CN101607804A - Concrete corrosion-proof rust-resisting permeation-resisting agent - Google Patents

Abstract

The invention relates to an additive of concrete, in particular to a concrete corrosion-resistant rust-resistant anti-permeability agent. Is prepared by mixing sodium methylene naphthalene sulfonate, rosin soap composite foam stabilizer, sodium bentonite, calcium nitrite or dicyclohexyl nitrite, a sulfate complexing agent and an anti-permeability component according to a certain proportion. Compared with scientific experiments, the concrete corrosion-resistant rust-resistant permeability-resistant agent can obviously improve the corrosion resistance and the destructive performance of the concrete in seawater and marine environments, the compression resistance, the volume stability, the impermeability, the freezing resistance, the carbonization resistance, the chloride ion permeability resistance and the like of the concrete, and various indexes are improved to different degrees.

Description

Concrete corrosion-prevention rust-resistance penetration-resistant agent

Technical field

The present invention relates to a kind of concrete additive, is a kind of concrete corrosion-prevention rust-resistance penetration-resistant agent specifically.

Background technology

The too early destruction of reinforced concrete constructional work under the ocean environment is typical case's performance of concrete structures deterioration.Concrete structures suffers the violent corrosion of seawater and other corrosive environments, often just occurs in several years significantly degrading, phenomenon such as cracking and steel bar corrosion.Hazardness for seawater and other corrosive environments does not cause enough attention for a long time, to its research also great majority is from the corrosion process of one-sided consideration Steel Concrete and the working conditions of structures, and ignored interaction with ocean environment or other corrosive environments, so heightened awareness ocean and other corrosive environments are to the mechanism of corrosion of concrete structures, be to prevent concrete structures premature corrosion destruction, improve the prerequisite of weather resistance.Ocean and other corrosive environments mainly show following several respects to the corrosive nature of concrete structures: the vitriol in the seawater is to concrete swelling property corrosive nature; Magnesium salts in the seawater is to concrete cationic exchange type corrosive nature; Villaumite in the seawater is to concrete dissolution type corrosive nature; The physical action of oceanic climate alternation of wetting and drying; The maritime concrete structures spatter unfreezing and the sulphate chemical effect that the district is subjected in tidal range district and wave.

Summary of the invention

The purpose of this invention is to provide a kind of concrete corrosion-prevention rust-resistance penetration-resistant agent that can improve the weather resistance of concrete structure.

For achieving the above object, the present invention is by the following technical solutions:

Concrete corrosion-prevention rust-resistance penetration-resistant agent of the present invention comprises following compositions in weight portion:

Methanonaphthalene sodium sulfonate 0.6-1.0 gram

The compound suds-stabilizing agent 0.01-0.02 gram of rosined soap

Sodium bentonite 0.5-0.7 gram

Calcium nitrite or nitrous acid bicyclohexane 0.9-1.1 gram

Vitriol complexing agent 1.0-1.1 gram

Impervious component 0.5-0.6 gram.

Described impervious component is the organosilane mixture.

Contrast through scientific experimentation, use this concrete corrosion-prevention rust-resistance penetration-resistant agent can obviously improve the corrosion and the destructive characteristics of concrete anti-seawater and ocean environment, concrete compressive property, volume stability, impermeability, frost resistance, anti-carbonization ability, resistance of chloride ion penetration energy, etc. many index in various degree raising is all arranged.

One, test materials and test method

1.1 test materials and correlated performance parameter

Table 1-1 cement type and correlated performance parameter

* annotate: 2h5 represents 2 hours 5 minutes, all the other expressions and the like.

The kind and the correlated performance parameter of table 1-2 sand

Table 1-3 rubble kind and correlated performance parameter

Table 1-4 flyash kind and correlated performance parameter

Table 1-5 blast-furnace slag kind and correlated performance parameter

1.2 test method

1.2.1 water-reducing rate test

According to " concrete admixture " (GB 8076-1997) regulation, water-reducing rate is slump normal concrete and mix the ratio of admixture concrete unit consumption of water when basic identical.The slump is measured according to GBJ 80 prescriptive procedures, and water-reducing rate is calculated as follows:

$W_R=\frac{W_0-W_1}{{\mathrm{<figure-callout\; id="0"\; label="W"\; filenames="A2009100082720048H1.png,A2009100082720048H2.png"\; state="\{\{state\}\}">W</figure-callout>}}_0}\&times;100$

In the formula: W _R-water-reducing rate, %;

W ₀-normal concrete unit consumption of water, Kg/m ³

W ₁-mix admixture concrete unit consumption of water, Kg/m ³

The water-reducing rate that test records concrete corrosion-prevention rust-resistance penetration-resistant agent sees Table 1-6.

The water-reducing rate of table 1-6 concrete corrosion-prevention rust-resistance penetration-resistant agent

1.2.2 compressive strength rate test

Stipulate according to " concrete admixture " (GB 8076-1997), compressive strength rate with mix admixture concrete and normal concrete with the length of time ultimate compression strength ratio represent, mix the ultimate compression strength of admixture and normal concrete and test and calculate by GBJ 81, compressive strength rate is calculated as follows:

$R_S=\frac{S_t}{S_c}\&times;100$

In the formula: R _S-compressive strength rate, %;

S _t-mix the concrete ultimate compression strength of admixture, MPa;

S _cThe ultimate compression strength of-normal concrete, MPa.

Mix concrete corrosion-prevention rust-resistance penetration-resistant agent concrete compressive strength rate test-results in the different length of time list in table 1-7.

Table 1-7 mix concrete corrosion-prevention rust-resistance penetration-resistant agent concrete compressive strength rate in the different length of time

1.2.3 the slump is through time loss test

The slump when measuring after the firm discharging of concrete, the discharging 60min behind the 30min and discharging respectively with reference to " normal concrete mix method for testing performance " (GBJ 80-85).

Carry out slump determination test after the concrete discharging immediately, used concrete mix dress mould or do not re-use remainingly mixes and stirs covering surfaces after the material barrelling, prevents that moisture is excessively lost.Pour an amount of mix in agitator kettle appropriateness stirring behind the 30min, measure concrete mix slump value after the discharging.Repeat above-mentioned steps behind the 60min and measure mix slump value.Test shows that the concrete slump value by different time changes, reflect the concrete 1h slump through the time loss be no more than 10%.

For the performance of further check concrete corrosion-prevention rust-resistance penetration-resistant agent and with the adaptability of cement and mineral admixture, experimental study concrete slump through the time loss and divergence thereof through the time lose.The concrete mix that adopts is listed in table 1-8, concrete slump through the time loss and divergence through the time lost data as showing shown in the 1--9.

Table 1-8 concrete mix

Annotate: 1.F---flyash, the excess coefficient gets 1.5;

2..S---slag powders, its addition content are 25% of flyash total amount.

The table concrete slump of 1-9 and divergence

By table 1-9 as seen, concrete slump value when 60min of singly mixing concrete corrosion-prevention rust-resistance penetration-resistant agent drops to 165mm by initial 195mm, and slump value descends 15%.And during the concrete 60min of admixture concrete corrosion-prevention rust-resistance penetration-resistant agent and mineral admixture slump value about 200mm, big slump-loss does not appear, show the slump lower when concrete adopts CW concrete corrosion-prevention rust-resistance penetration-resistant agent and mineral admixture to carry out two mixing through the time lose and good slump retentivity.Illustrate that also concrete corrosion-prevention rust-resistance penetration-resistant agent and cement and mineral admixture have good adaptability.This mainly is because flyash is ganoid globular glass body particle, and concrete is had tangible plasticising water-reduction, and its " shape effect " and " separating the wadding effect " obtained good embodiment.Adding coal ash and slag powders make concrete have more good micro-aggregate grating system, thereby have compensated concrete slump-loss effectively simultaneously.Test shows that also Adding Mineral Admixtures can significantly improve concrete rheological property.In engineering, adopt concrete corrosion-prevention rust-resistance penetration-resistant agent, and require the lower slump through the time when losing and mineral admixture simultaneously admixture use and have better effect.

Concrete divergence also is its mobile important indicator, for the concrete flowability of systematic study, also carried out the concrete divergence through the time loss mensuration.The test-results of table 1-9 shows that mineral admixture can significantly improve concrete divergence, and the concrete initial extension degree of Adding Mineral Admixtures improves 31% than the concrete divergence of singly mixing concrete corrosion-prevention rust-resistance penetration-resistant agent.Flyash and slag powders make concrete mix show lower divergence through the time lose.

1.2.4 concrete corrosion-prevention rust-resistance penetration-resistant agent is to steel bar corrosion influence test

Steel bar corrosion accelerated test procedures in the reference " concrete admixture " (GB8076-1997), the check admixture is to the action of rust and the influence of reinforcing bar.

1. plant and instrument

(output current scope is not less than 0～2000 μ A to potentiostat, can change 0～2V continuously, precision≤1%), rosin=9: 1), plastics have end movable mold (size 40mm * 100mm * 150mm) mercurous chloride electrode, timing watch, copper core plastic cord, insulation compound (paraffin:.

2. testing sequence and precaution

(1) makes the reinforcing bar electrode

I level building iron is processed into the electrode that length is 100mm, the surfaceness maximum permissible value is the test specimen of 1.6 μ m, soak successively with gasoline, ethanol, acetone and to wipe degrease, and the lead of the long 130mm～150mm that at one end burn-ons, carefully wipe solder paste with ethanol again, at the two ends of reinforcing bar, dip-coating hot melt paraffin rosin insulation compound, making the middle length of exposure of reinforcing bar is 80mm, calculates its surface-area.It is standby that reinforcing bar is after treatment put into moisture eliminator, three of every group of test specimens.

(2) mix the fresh mortar of system

Adopt water cement ratio 0.5, cement-sand ratio preparation in 1: 2 mortar, water is distilled water, the standard sand that sand is used for the check strength of cement, cement is reference cement, dry mixing 1min, wet-mixing 3min.Admixture adds with mixing water in proportion.

(3) mortar and electrode are gone into mould

Pour in the die trial mixing the mortar that makes, water half (about thick 20mm) earlier.Two handled well does not have the parallel mortar surface that is placed on of the reinforcing bar of iron mold electrode on inspection, and spacing 40mm pulls out lead, and it is floating to fill mortar then, and raps several lower side panels, makes it closely knit.

(4) connect test apparatus

Press the new sand cutting slurry of Fig. 1-1 polarized potential test set synoptic diagram and connect testing apparatus, the electrode input lead is a Bundling conducting wire, in accordance with regulations three clips are connect anode reinforcing bar, negative electrode reinforcing bar and mercurous chloride electrode respectively, connect " research " and "+" connection hole of instrument as anode with a reinforcing bar, another root reinforcing bar be negative electrode (being supporting electrode) connect instrument " assist " connection hole, again the lower end of mercurous chloride electrode is aimed at reinforcing bar anodic center position, contact with new sand cutting slurry surface, and perpendicular to the mortar surface, the lead of mercurous chloride electrode connects " reference " connection hole of instrument.

(5) test

Before the illogical impressed current, read the spontaneous potential V (being the current potential difference between reinforcing bar anode and the mercurous chloride electrode) of anode reinforcing bar earlier.Connect impressed current, and by current density 50 * 10 ^-2A/m ²(i.e. 50 μ A/cm ²) adjust μ A and show to desired value.Start the clock simultaneously, successively by 2,4,6,8,10,15,20,25,30min writes down the anodic polarization potential value respectively.

3. test-results treatment process

With the mean value of three test electrode measuring results, as the measured value of reinforcing bar anodic polarization current potential, be X-coordinate with time, the anodic polarization current potential is an ordinate zou, draws current potential-time curve, continuous current as shown in Figure 1, current potential-time curve analysis chart.According to the influence to steel bar corrosion such as the cement in current potential-time curve judgement mortar, admixture.

4. continuous current, current potential-time curve map analysis

After the electrifying electrodes, anode reinforcing bar current potential rises to positive dirction rapidly, and reaches the oxygen evolution potential value at short notice, and through the 30min test, potential value does not have obvious reduction, as the curve among Fig. 1 1. shown in, belong to Passivation Curve.Show that anode rebar surface passive film is excellent, the admixture of surveying be harmless to reinforcing bar.

After the energising, anode reinforcing bar current potential rises to positive dirction earlier, along with descending gradually again, as the curve among Fig. 1-2 2., illustrates that the rebar surface passive film is partially damaged.And 3. the curve among Fig. 1 belongs to activation curve, and it is serious to illustrate that the rebar surface passive film destroys.Both of these case shows that all rebar passivation film goes to pot.But at this moment still can not make clear and definite judgement to the influence of steel bar corrosion to contained cement, admixture in the test mortar, also must remake the measurement of sclerosis mortar anodic polarization current potential, or carry out long-term corrosion test, with further differentiation admixture reinforcing bar there is non-corroding harm.

After the energising, 1. and the intermediate state situation 2. anode reinforcing bar current potential curve occurs among Fig. 1 over time sometimes, be current potential earlier to pros rise to higher positive electricity place value (〉=+600mV), continue one period steady time, gradually on a declining curve then, if potential value descends rapidly, then belong to the 2. situation; If potential value descends slowly, and change few, the time of then testing and writing down current potential prolongs 30min again, write down the anodic polarization potential value in per 5 minutes respectively, if keeping stable, potential curve no longer descends, can think that rebar surface still can remain intact passive film, the admixture of surveying be harmless to reinforcing bar, if potential curve continues to continue to descend, can think the breakage of rebar surface passive film and change active state into,, also must remake the measurement of sclerosis mortar anodic polarization current potential for this situation, or carry out long-term corrosion test, with further differentiation admixture reinforcing bar there is non-corroding harm.

5. concrete corrosion-prevention rust-resistance penetration-resistant agent is to the influence research of steel bar corrosion

The corrosion and destruction of reinforcing bar is considered to the main reason that the structures weather resistance reduces, so in GB 8076-1997 " concrete admixture " rules, admixture has been used as clear and definite regulation to steel bar corrosion, should there be corrosion harm in admixture to reinforcing bar.Steel bar corrosion accelerated test procedures (new sand cutting slurry method) is adopted in this test, has checked the influence of concrete corrosion-prevention rust-resistance penetration-resistant agent to steel bar corrosion, owing to contain the corrosion-prevention rust-resistance composition in the concrete corrosion-prevention rust-resistance penetration-resistant agent, so simultaneously its effect is checked.Test parameter with the results are shown in the table 1-10～table 1-13, the continuous current of test, current potential-time curve such as Fig. 2, shown in Figure 3.

Table 1-10 admixture concrete corrosion-prevention rust-resistance penetration-resistant agent test parameter

Anodic polarization potential value during table 1-11 admixture concrete corrosion-prevention rust-resistance penetration-resistant agent

The test parameter of table 1-12 admixture concrete corrosion-prevention rust-resistance penetration-resistant agent and NaCl

Anodic polarization potential value when table 1-13 admixture concrete corrosion-prevention rust-resistance penetration-resistant agent and NaCl

As seen from Figure 2, energising back anode reinforcing bar current potential rises to positive dirction rapidly, in 8min, reach the oxygen evolution potential value, through test in 30 minutes, current potential does not have obvious reduction, illustrate that continuous current, current potential-time curve are Passivation Curve, promptly anode rebar surface passive film is excellent, shows that concrete corrosion-prevention rust-resistance penetration-resistant agent has passivation to reinforcing bar.

As seen from Figure 3, when admixture concrete corrosion-prevention rust-resistance penetration-resistant agent and NaCl, curve is an activation curve, illustrates that the rebar surface passive film destroys.Concrete corrosion-prevention rust-resistance penetration-resistant agent contains resistance rust composition, and corrosion potential is positive, and has the effect of resistance rust, can reduce the potential hazard of steel bar corrosion.But, (as adopting the situation of seawater as mixing water) both made the admixture rust inhibitor when containing too high salt amount in the mixture, and reinforcing bar still the intensive action of rust can occur, so in construction, should strictly control chloride content in the concrete raw material, guarantee that reinforcing bar is not corroded.

1.2.4 expansion contraction test

Reference standard " normal concrete long-term behaviour and durability test method " (GBJ 82-85) is tested.Present method is applicable to measures concrete sample under the temperature of stipulating, humidity condition, is not subjected to the caused length variations of external force effect.

1. test material preparation

When measuring concrete shrinkage, the prism test specimen that adopts 100mm * 100mm * 400mm is as the test test specimen.The pre-buried copper gauge head in test specimen two ends.

2. test apparatus

Concrete shrinkage instrument, thermostatic constant wet chamber's (can make room temperature remain on 20 ± 2 ℃, relative humidity remains on 60 ± 5%) etc.

3. testing sequence and precaution

(1) concrete sample (was counted when ready-mixed concrete adds water) when the 3 day length of time, took out and moved into thermostatic constant wet chamber immediately from standard curing room and measure its initial length, its distortion reading of time interval measurement according to the rules after this.Because the criteria of right and wrong maintenance test specimen that adopts, so should be with test specimen at the indoor 4h that presets earlier of fixed temperature and humidity, measuring its initial value, so that they have same temperature reference.

(2) should use the zero point of par instrument calibration earlier before the measurement, and in the mensuration process, check at least again 1～2 time.Surpass ± 0.01mm if find the deviation of zero point and initial value when checking, should redeterminate after the zeroing.

(3) test specimen position, the direction of at every turn placing on retractometer all should be consistent.Should indicate corresponding mark on the test specimen.Test specimen should be gently steady careful in placement and take-off time, do not make its collision dial framework and table bar, if bump, then should take off test specimen, checks zero point with par again.

(4) test specimen is placed on the shelf that does not absorb water in that fixed temperature and humidity is indoor, and the bottom surface is built on stilts, and it always supports area should not take advantage of the test specimen cross section length of side (mm) greater than 100, should leave the gap of 30mm between each test specimen at least.

4. the concrete shrinkage value is calculated as follows:

${\mathrm{\&epsiv;}}_{\mathrm{st}}=\frac{L_0-L_t}{L_b}$

In the formula: ε _St-trial period is t days a concrete shrinkage value, and t is counted when measuring initial length;

L _bThe measurement gauge length of-test specimen when measuring with the concrete shrinkage instrument, should equal the distance of two gauge head inboards, and promptly the length of concrete sample deducts 2 times of gauge head lengths of embedment, mm;

L ₀The initial reading of-test specimen length, mm;

L _tThe length reading that-test specimen recorded during for t in trial period, mm.

The arithmetical av of getting three values calculates and is accurate to 10 * 10 as this concrete shrinkage value ^-6

5. expansion shrinkage research

The compound nano level sodium bentonite of handling through hydrophobisation in the middle of the concrete corrosion-prevention rust-resistance penetration-resistant agent, it is after concrete hardening, water-repellent layer is dissolved by alkaline matter gradually, moisture in the wilkinite absorptive hair pore or the planar water on the cement particle surface produce and expand, fill pore and micro gap, significantly increase density, anti-carbonization and the anti-drying shrinkage of maturing, thereby increase the volume stability of maturing.

(1) contractile mechanism analysis

The Qin Wei ancestors give birth to and to think: " people have given very big concern to contraction, but noticeable be not contraction itself, but owing to it can cause cracking ".In recent years, domestic and international many scholars find that there is early-age shrinkage rimose problem in high performance concrete, its reason is under the situation of low water-cement ratio or low water binder ratio, mix more concrete and can produce self-desiccation (Self-drying or Self-desiccation) with quite active mineral admixture, thereby cause concrete spontaneous contraction (Autogenous Shrinkage), concrete inner structure is sustained damage and produce microfracture.It is because the influence of outside atmosphere relative humidity that concrete produces self-desiccation, and free water amount spontaneously reduces and the dry-out phenomenon that causes in the concrete inner structure minute aperture, and causes concrete shrinkage strain.Therefore, the shrinkage character of serious analysis maturing is taked at measure, and is significant to the cracking that prevents to cause thus.

(2) test results and analysis

Mix proportion is listed in table 1-14, and the expansion and shrinkage value in concrete different length of times is listed in table 1-15, and the expansion contraction change curve in concrete different length of times as shown in Figure 4.

Table 1-14 concrete mix

Show the 1-15 concrete expansion and shrinkage value in the different length of times

Annotate: detecting test specimen maintenance and testing process is 30～50% in relative humidity all, and temperature is to carry out under 20 ± 2 ℃ the envrionment conditions.

By table 1-15 as seen, at 3d during the length of time, the concrete of admixture concrete corrosion-prevention rust-resistance penetration-resistant agent shows the microdilatancy phenomenon separately, mainly be because the concrete corrosion-prevention rust-resistance penetration-resistant agent of admixture has the microdilatancy composition, thereby make the concrete shrinkage value of its preparation significant reduction be arranged than the normal concrete test specimen, this for prevent concrete especially the early stage cracking of mass concrete be very important; The concrete sample shrinkage value of admixture 40% flyash is 67 * 10 ^-6, than the shrinkage value 75 * 10 of normal concrete ^-6Low by 11%, show early stage low contraction, mainly be that a large amount of admixtures of flyash help slowing down the hydration rate of concrete self because the activity of flyash is lower, thereby reduce whole contraction.And the concrete shrinkage value of admixture 10% slag powders is respectively 88 * 10 ^-6, higher by 15% respectively than the shrinkage value of normal concrete, shrinkage value increases gradually, mainly is because scoriaceous water-retentivity is relatively poor, thereby has increased the shrinkage value of concrete sample.

By table 1-15 as seen, the mineral admixture change of component, concrete shrinkage value changes obviously, and the concrete shrinkage value of admixture 40% flyash reaches constant at first, and less than with the scoriaceous concrete shrinkage value of the admixture in the length of time.Along with the prolongation of curing age, the scoriaceous concrete sample of admixture shows bigger shrinkage value.The test of document also shows, the concrete shrinkage value of admixture slag powders increases along with the increase of slag powders volume, the concrete of admixture slag powders shows too along with the phenomenon that increases is shunk in the raising of fine slag contents in this test, and the concrete sample of admixture slag powders shrinks and is greater than the concrete sample of not mixing slag powders on long terms.Excessive contraction causes concrete cracking, is disadvantageous to concrete protection against corrosion and weather resistance, and test shows that at the total volume of complex mineral blending material be at 40% o'clock, and the volume ratio of flyash and slag micropowder should be not less than 3: 1.

1.2.5 impervious test

Reference standard " normal concrete long-term behaviour and durability test method " (GBJ 82-85) is tested.Present method is applicable to measures the concrete impervious grade in sclerosis back.

1. test material preparation

Adopting the end face diameter is 175mm, and the bottom surface diameter is 185mm, highly is the Rotary-table of 150mm.24h form removal behind the specimen molding brushes away both ends of the surface cement serous coat with wire brush, sends into maintenance in the standard curing room then.Test specimen maintenance to 28 is tested day length of time.

2. testing installation

Concrete impervious instrument, pressure testing machine, baking oven etc.

3. testing sequence and precaution

(1) the test specimen maintenance is taken out to testing the day before yesterday, and the surface is dried, and is coated with the sealing material of one deck fusing then in its side, immediately on pressing machine, test specimen is pressed in the specimen sleeve after the baking oven preheating, slightly after the cooling, pressure relief is contained on the Anti-leakage instrument together with specimen sleeve and tests.

(2) test is 0.1MPa from hydraulic pressure.Increase hydraulic pressure 0.1MPa every 8h later on, and note observing the infiltration situation of test specimen end face at any time.

(3) when having 3 test specimen end faces to be to have the infiltration phenomenon in 6 test specimens, promptly stop test, write down hydraulic pressure at that time.

(4) in process of the test, if find that water oozes out from the test specimen periphery, stop test, reseal.

4. test-results is calculated

Concrete impervious grade is calculated with 4 peak pressures when infiltration occurring in every group of 6 test specimens, and is as follows:

P＝10H-1

In the formula: the impervious grade of P-;

Water pressure in H-6 test specimen during 3 infiltrations, MPa.

5. the concrete impervious research of admixture concrete corrosion-prevention rust-resistance penetration-resistant agent

Concrete mix and correlation parameter are listed in table 1-16, and its impervious test-results is listed in table 1-17.

Table 1-16 concrete mix and correlation parameter

The concrete impermeability of table 1-17

By table 1-17 as seen, concrete corrosion-prevention rust-resistance penetration-resistant agent and mineral admixture are two to be mixed, and the concrete anti-permeability performance of preparation is far superior to normal concrete.14d during the length of time normal concrete under the low water pressure of 0.4MPa, just produce permeable phenomenon, and that the concrete of admixture concrete corrosion-prevention rust-resistance penetration-resistant agent does not take place under the water pressure of 2.0MPa yet is permeable, and the infiltration of sample is highly all lower.The concrete impermeability of 28d admixture concrete corrosion-prevention rust-resistance penetration-resistant agent during the length of time is compared with normal concrete to have greatly and is increased, under the water pressure of 3.5MPa, do not take place permeable yet, reason is the micro aggregate effect and the secondary hydration reaction of flyash and slag powders in the concrete, and through moisture in the nano level sodium bentonite absorptive hair pore of hydrophobisation processing or the generation of the planar water on cement particle surface expansion, make the refinement of concrete aperture, communicating aperture is blocked, concrete density improves, thereby has significantly improved concrete anti-permeability performance.

The infiltration degree of depth of concrete sample shows among the table 1-17, two fly ashs and slag powders have higher degree of compactness and impervious ability than independent adding coal ash, the bleeding of concrete degree of depth of 14d independent adding coal ash of bleeding of concrete depth ratio of admixture complex mineral blending material during the length of time low 65%.Because the degree of compactness of hardened cement paste and the stacking states of gelling material powder before mixing water have substantial connection, cement particle diameter maximum, flyash and slag powders take second place (1/3-1/2 that is about the cement median size), these gelling material are through the mixing of suitable proportion, and feasible gelling material of mixing in the preceding concrete of water has the continuous microstage better than unitary system and joins form.The gelling material particle of different-grain diameter is filled mutually in the hydration process; reduced intergranular space, littler hole is filled in nano level sodium bentonite suction diffusion; thereby further reduced the overall porosity behind the composite gelled material system setting and harden, reduced concrete perviousness effectively.

Table 1-17 data show that the concrete of admixture concrete corrosion-prevention rust-resistance penetration-resistant agent has higher impervious ability, and 28D 3.5MPa in length of time hydraulic pressure infiltration height down can drop to below the 10mm.Mainly be owing to also contain the bleed component in the concrete corrosion-prevention rust-resistance penetration-resistant agent, after being adsorbed onto on the liquid-vapo(u)r interface, surface free energies reduces, reduced the surface tension of solution, make concrete mix in whipping process, very easily produce many small CABs, bubble diameter and at interval mostly below 200 μ m, thus concrete water retention capacity improved, the bleeding performance of concrete mix is greatly reduced.Because the obstruct of bubble makes the complications that free evaporation of water route becomes in the concrete mix, tiny, dispersion, thereby has changed quantity capillaceous and characteristic, and concrete impermeability is significantly improved.

1.2.6 corrosion-resistant coefficient test

1. test material preparation

Make two groups of concrete samples, put into 20 ± 2 ℃ fresh water behind one group of normal curing 7D, put into 20 ± 2 ℃ of seawater behind another group normal curing 7D and carry out long period of soaking.Maintenance is carried out the concrete cube compressive strength test to two groups of test specimens respectively according to GBJ 81-85 to certain length of time, and calculates the concrete corrosion resistant coefficient according to following formula:

In the formula: f ₁-at the medium-term and long-term concrete sample ultimate compression strength of soaking of seawater, MPa;

f ₂-at the medium-term and long-term concrete sample ultimate compression strength of soaking of fresh water, MPa.

2. corrosion-resistant coefficient research

Concrete mix that test is adopted and the corrosion-resistant coefficient that soaked 7 months in seawater are listed in table 1-18.

Table 1-18 concrete mix and corrosion-resistant coefficient

^*The chemical ingredients of corrosive medium: Cl ^-Be 19000g/L, SO ₄ ^2-Be 7000mg/L, Na ⁺Be 12655mg/L, Mg ²⁺Be 2000g/L.

^*The preparation explanation of corrosive medium: in order to add the corrosive power of dense medium, corrosive medium is the MgSO that has added some amount in seawater ₄2H ₂O, MgCl ₂6H ₂O and NaSO ₄The back is formulated.

By table 1-18 as seen, do not mix the concrete intensity of mineral admixture and occur reducing largely after the seawater long period of soaking, its corrosion-resistant coefficient is also minimum.And the concrete corrosion resistant coefficient of compound adding coal ash and slag powders is 0.94, has significantly improved the ability of concrete anti-seawater corrosion.Because Ca (OH) ₂With drated calcium aluminate is to cause cement stone corrosive principal element, admixture active mineral admixture in concrete, and part has replaced the amount of cement, makes C ₃The relative content of A decreases, and because its secondary hydration reaction can mass consumption Ca (OH) ₂Thereby, can improve concrete corrosion resistance nature.The concrete resistance to corrosion of admixture complex slag and concrete corrosion-prevention rust-resistance penetration-resistant agent is stronger simultaneously, and its corrosion-resistant coefficient reaches 0.99.This is that sanitas can be combined to insoluble salt or complex compound with objectionable impurities, and leaches from concrete by means of diffusion owing to contain anticorrosion density composition in the concrete corrosion-prevention rust-resistance penetration-resistant agent.Sanitas can also suppress Cl ^-Activation or quicken Cl ^-Be combined to the hydration calcium chloroaluminate of indissoluble, thereby slow down its direct influence reinforcing bar.Micro pores is filled in density composition nano level sodium bentonite suction diffusion, significantly improves concrete degree of compactness, therefore reduces concrete perviousness effectively, makes corrosive medium be difficult to infiltrate inside concrete.

1.2.7 anti-carbonization test

Reference standard " normal concrete long-term behaviour and durability test method " (GBJ 82-85) chapter 8 is tested.Present method is applicable to the carbonizing degree that is determined at concrete sample in the certain density carbon dioxide gas body medium, with this concrete anti-carbonization ability of evaluation.

1. test material preparation

Carbonization test adopts the prism concrete sample of 100mm * 100mm * 400mm.Carried out carbonization the 28 day length of time, carbonization test took out from curing room in preceding 2 days, dried by the fire 48h down at 60 ℃.The test specimen that drying is handled, except that staying next side, the paraffin that remaining surface is melted with heat is sealed, on the side along the length direction with the 10mm spacing parallel lines that draw, as the measurement point of being scheduled to carbonation depth.

2. testing installation

Carbonization case, gas analyzer, carbonic acid gas air feeder (gas cylinder, tensimeter and under meter) etc.

3. testing sequence and precaution

(1) treated test specimen is put on the brandreth of carbonization case, the spacing that each test specimen stands between the surface of carbonization should be 50mm at least.

(2) with after the sealing of carbonization case, start gaseous exchange device in the case, pour carbonic acid gas slowly, and measure gas concentration lwevel in the case, progressively regulate the flow of carbonic acid gas, the gas concentration lwevel in the case is remained on about 5%.Available water catcher or put into silica gel during whole test is controlled in 70 ± 5% the scope relative humidity in the case.Carbonization test should carry out under 20 ± 5 ℃ temperature.

(3) carbonization is taken out each test specimen to 3,7,14,28 days the time, measures its carbonation depth behind the broken type.On pressure testing machine, break type since an end with split the law.The thickness of each excision is half of specimen width, will break behind the type cut surface of test specimen with paraffin and seal, and puts into case again and continues carbonization, up to next one trial period.

(4) test specimen that will excise gained partly scrapes off powder remaining on the section, drips concentration immediately and be 1% phenolphthalein spirituous solution.Behind 30s, measure side each point carbonation depth with Steel Ruler by measurement point of 10mm that original mark is drawn.If just be embedded with the coarse aggregate particle on the carbonization line of delimitation at measuring point place, the mean value of then desirable this place, particle both sides carbonation depth is as the depth value of this point, and carbonation depth is accurate to 1mm.

4. test-results is calculated

Concrete is calculated as follows at the average carbonation depth of each test during the length of time:

$\stackrel{\&OverBar;}{d_i}=\frac{\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{d}_i}{n}$

In the formula: d _iThe average carbonation depth of-test specimen carbonization after t days, mm; d _iThe carbonation depth of each measuring point on the-side, mm; Measuring point sum on the n-side.

5. interpretation of result method

Draw the relation curve of carbonization time and carbonation depth with the carbonation depth that calculates gained each length of time, to be illustrated in the concrete carbonization rule of development under this condition.

6. anti-carbonation properties research

Ca in the concrete (OH) ₂With CO in the atmosphere ₂Under rational humidity condition, chemical reaction takes place generate CaCO ₃, being called carbonization of concrete, its chemical equation is:

Ca(OH) ₂+CO ₂+H ₂O→CaCO ₃+2H ₂O

Along with the growth of time, carbonization can improve the intensity of concrete self, shrinks but the carbonization of concrete effect makes it produce carbonization, and reduces concrete basicity, quickens the corrosion of reinforcing bar, and this is totally unfavorable to the Steel Concrete that is in the ocean environment.This test has been carried out systematic research at carbonization of concrete performance under the situation of the more mineral admixture of admixture, has studied the influence of different standards curing age to concrete carbonizing performance simultaneously.

(1) concrete anti-carbonization

The early stage effects of action of considering the more complex mineral blending material of admixture is not obvious, in order to give full play to it to concrete good action effect, the straight cement concrete of normal curing 28d and the breeze concrete of mixing of normal curing 90d are carried out high-speed carbonation test, systematic study carbonization of concrete performance under the more flyash of admixture and the complex mineral blending material situation, the mix proportion and the flash carbonization degree of depth are listed in table 1-19 respectively, and each organizes concrete flash carbonization curve shown in Fig. 1-5.

The table 1-19 concrete mix and the flash carbonization degree of depth

As show 1-19 and shown in Figure 4, for various concrete, during flash carbonization 3d, carbonation depth is 6～8mm; During flash carbonization 7d, carbonation depth is 9～11mm, and after this concrete carbonization depth begins to occur bigger difference; During flash carbonization 14d, the concrete sample carbonation depth of adding coal ash is 16mm separately, and is higher by 18.7% than the concrete of not mixing adulterant.During flash carbonization 28d, the concrete sample carbonation depth of adding coal ash reaches 21mm separately, and is higher by 30% than the carbonization of concrete degree of depth of not mixing adulterant, higher by 20%～38% than the concrete of admixture complex mineral blending material.Mainly be because behind the concrete hydrating of the especially independent adding coal ash of Adding Mineral Admixtures, carbonizable substance Ca (OH) in the unit volume ₂Content reduces, and because the secondary hydration reaction of active mineral admixture also will consume a part of carbonizable substance Ca (OH) ₂, make its content still less, so carbonization speed is accelerated.

As shown in Figure 4, secondly the concrete carbonization depth maximum of single fly ash is the two concrete of mixing of flyash and slag powders, the concrete carbonization depth minimum of not mixing adulterant.In sum, the concrete carbonization depth of admixture 40% mineral admixture is greater than the concrete of not mixing mineral admixture.At identical flash carbonization during the length of time, the concrete carbonization depth of normal curing 90d is a little more than the straight cement concrete of normal curing 28d, this and K.K.Sideris ^[65]Conclusion (of pressure testing) consistent.Mainly be that the breeze extent of hydration develops gradually because of the prolongation along with curing age, concrete density increases gradually, thereby has hindered the diffusion of carbon dioxide to inside concrete, the carrying out of having slowed down concrete carbonization effectively.

(2) carbonization speed coefficient analysis

The concrete carbonization characteristic curve is the curve that characterizes the concrete carbonization depth change with time, shown in Fig. 1-5.The carbonization of concrete performance can be evaluated with carbonization of concrete velocity factor α, so the carbonization of concrete velocity factor is studied.Both domestic and external a large number of experiments show that, under normal atmospheric condition, the concrete carbonization characteristic curve, available power function equation is represented:

$D=\mathrm{\&alpha;}\sqrt{t}$

In the formula:

The D-concrete carbonization depth, mm;

T-concrete carbonization length of time, d;

The alpha-carbon velocity factor.

Utilize the SQL function among the Origin, adopt above-mentioned function that the concrete carbonization characteristic curve is carried out match, thereby determine respectively to organize the carbonization of concrete velocity factor shown in table 1-21 and 1-22.

Table 1-20 concrete carbonization velocity factor

By table 1-20 as can be seen, under different curing age, the concrete of single fly ash all has the highest carbonization speed coefficient.As show shown in the 1-20, normal curing 28d mixes the complex slag concrete, and when flyash and slag powders ratio were 3: 1, having minimum carbonization speed coefficient was 2.844.Along with the normal curing growth in the length of time, the activity of mineral admixture is brought into play gradually, and the carbonization of concrete velocity factor of mixing mineral admixture can reduce gradually.

(3) structures carbonization time limit prediction

Document shows, can utilize the concrete flash carbonization degree of depth, predicts the carbonization time limit of the concrete structures of different protective layer thickness:

${\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="A2009100082720049H2.png"\; state="\{\{state\}\}">d</figure-callout>}}_2=d_1\sqrt{\frac{t_2{C}_2}{t_1{\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="A2009100082720049H2.png"\; state="\{\{state\}\}">C</figure-callout>}}_1}}$

In the formula:

d ₂The natural carbonation depth of certain age concrete of-prediction, mm;

d ₁The concrete degree of depth that-rapid method is measured, mm;

t ₂The natural carbonization length of time of-prediction, year;

t ₁The carbonization time that-rapid method is measured, year;

C ₁-flash carbonization CO ₂Concentration, %;

C ₂-predict good surrounding medium CO ₂Mean concns generally gets 0.03%.

Concrete cover is an ocean environment with the direct barrier of contact of reinforcing bar, and reinforcing bar is remained in certain alkaline environment, stops or slows down CO ₂With the infiltration of chlorion, prevent that reinforcing bar from being corroded.According to reinforced concrete structure erosion failure theory under the ocean environment, outside the Pass concrete safe operating life removes and to have with the material capability of concrete own,, suitably increase protective layer thickness with square being directly proportional of thickness of concrete cover, can improve work-ing life.Based on 7 days high-speed carbonation test data of table 1-19, the concrete structures carbonization time limit that calculates different protective layer thickness is shown in table 1-21.

The carbonization time limit of table 1-21 concrete structures

Calculation result shows, except the 4th group of bigger concrete of slag powders volume, when concrete cover is 60mm, all can satisfy design reference period and be the requirement in 100 years.

1.2.8 resistance of chloride ion penetration energy

Chlorion enters two kinds of approach usually in the concrete: the first " is sneaked into ", contains the admixture of chlorion and uses extra large sand etc. as employing; It two is " infiltrations ", and absorbs and permeate three kinds of modes and move to inside concrete by diffusion, pore ^[68]Because the ionic radius of chlorion is very little; its transfer ability in concrete is stronger; often pass concrete cover and gather, when its massfraction surpasses certain threshold value, will cause the destruction of rebar passivation film, and then cause the corrosion of reinforcing bar and the destruction of structures at rebar surface.The penetrating quality of chlorion in concrete often expressed with chloride ion content in the concrete and chlorion apparent diffusion coefficient.Adopt long-term natural immersion method to study the concrete resistance of chloride ion penetration energy of different grades, different proportion of composing complex mineral blending materials in this problem, comprise soluble chlorine ion content and the infiltration diffusion process in concrete thereof on the different depths.Test is measured maritime concrete natural immersion chloride ion content after 7 months in seawater with reference to " concrete chloride ion content measuring method ", calculates the concrete chloride ion apparent diffusion coefficient with reference to " standard test methods of the total spread coefficient of maturing chlorion ".

1. the natural immersion method is measured the permeability of concrete chloride ions test

Test with reference to " standard test methods of the total spread coefficient of maturing chlorion " that Shanghai Construction Science Research Inst. formulates.This test method is by measuring the concentration distribution of chlorion on the concrete depth direction, the total spread coefficient of the concrete chlorion of analytical calculation.Be applicable to the ocean port engineering and be subjected to the test of the total spread coefficient of Chloride of Concrete Structure of chloride erosion.

(1) testing installation and material

Concrete section cutting machine (cutting precision should reach 0.25mm), chlorine ion content determination device (measuring accuracy reaches 0.001%), seawater (its chemical ingredients sees Table " * " under the 1-18), other sealing class materials.

(2) preparation of test test specimen

The laboratory compact dimensions is the cubes concrete sample of 100mm * 100mm * 100mm, and maintenance is 7 days under standard conditions, is one group with three test specimens during test.Except that a side as the exposure, all the other each faces comprise on the exposure and all to seal with the no-solvent type epoxy coating less than the periphery of 5mm.

(3) testing sequence and precaution

1. the concrete sample with maintenance to 7 day length of time is soaked in the seawater, and makes liquid level of solution be not less than 20mm from the distance of exposure, and keeping envrionment temperature is 20 ± 2 ℃.Soak 3 week of seawater of usefulness and change once, treat that test specimen is dipped to regulation and takes out after the length of time.Remove concrete exposed surface residue (unavailable water flushing), and polish flat.

2. use concrete section cutting machine,, concrete sample is carried out stratified sampling by the aspect that is parallel to exposure along the direction of vertical exposure.The thickness of sampling layer should be less than 2mm, and outermost layer sampling weight should satisfy the uniform minimum weight of sampling concrete powder sample.

3. with reference to above-mentioned method, measure the chloride ion content of water soluble chloride in the concrete powder sample, the chloride ion content measuring accuracy should reach 0.001%.

(4) test-results is calculated

Be plotted in the distribution curve that the concrete degree of depth (apart from exposure m) goes up chlorine ion concentration (%).Concrete surface chlorine ion concentration Cs, apparent diffusion coefficient Da and chlorine ion concentration distribution curve carry out non-linear regression with method of least squares.First point in the chlorine ion concentration curve, promptly outermost layer point should be rejected in regression analysis, and other each point satisfies following formula:

$C(x,t)=C_s-(C_s-C_i)\mathrm{erf}\left(\frac{x}{2\&CenterDot;\sqrt{D_a\&CenterDot;t}}\right)$

In the formula:

C (x, t)-exposure duration is when being t, the chlorine ion concentration at degree of depth x place, %;

The distance of x-exposure and sampling interlayer (a sampling layer center), m;

The time that the t-concrete is exposed in the bar in chlorine salt solution to be continued, s;

C _sThe chlorine ion concentration of-concrete exposed surface, %;

C _iInitial chlorine ion concentration of-concrete or background concentration, % considers that when choices of raw materials the content to chlorion has carried out strict qualification, simultaneously in order to simplify calculating, gets C _i=0;

D _aTotal spread coefficient of-chlorion or apparent diffusion coefficient, m ²/ s;

The erf-error function, its value can be looked in standard mathematics book of reference commonly used and get.

C _sValue is the theoretical value that is drawn by regression analysis, is not actual surperficial chlorine ion concentration.

$\mathrm{erf}\left(x\right)=\frac{2}{\sqrt{\mathrm{\&pi;}}}(x-\frac{{\mathrm{<figure-callout\; id="3"\; label="x"\; filenames="A2009100082720049H2.png"\; state="\{\{state\}\}">x</figure-callout>}}^3}{3\&CenterDot;1!}+\frac{x^5}{5\&CenterDot;2!}-\frac{x^7}{7\&CenterDot;3!}+\&CenterDot;\&CenterDot;\&CenterDot;)=\frac{2}{\sqrt{\mathrm{\&pi;}}}\&CenterDot;\underset{i=1}{\overset{\&infin;}{\mathrm{\&Sigma;}}}{(-1)}^{i+1}\frac{x^{2i-1}}{(2i-1)(i-1)!}$

(5) test data analyzer

According to the chloride diffusion coefficient standard that Mr. Tang Luping proposes, judge this concrete resistance of chloride ion penetration energy, shown in table 1-22.

Table 1-22 chloride diffusion coefficient reference standard

2. concrete chloride ion content is measured

Carry out Determination of chlorine ion content in the concrete with reference to NT BUILD208, AAHSTO T260, " marine traffic engineering concrete test rules " (JTJ 270-98) and " building structure detection technique standard " (GBT 5034-2004), present method is applicable to water-soluble chlorine ion content determination in the concrete.

(1) testing installation and material

The Silver Nitrate standardized solution of drop-burette (50ml), transfer pipet (50ml), Erlenmeyer flask, salpeter solution (1+3), phenolphthalein indicator (10g/l), 0.02N, 5% potassiumchromate indicator.

(2) testing sequence and precaution

1. with the concrete cube test specimen of normal curing 7d, except that a side as the exposure, all the other each faces comprise on the exposure and all to be sealed with the no-solvent type epoxy coating less than the periphery of 5mm, do the long period of soaking test.

The test specimen that 2. will soak in seawater 210 days takes out, remove concrete exposed surface residue, after treating the test specimen airing, get powder with section cutting machine mill, every 2mm degree of depth sampling on cube specimen, and whole sieves by 0.63mm, with powder collection to being mixed together even representative sample as this layer.Then sample is placed 60 ℃ baking oven baking 24 hours, putting into moisture eliminator after the taking-up, to be cooled to room temperature standby.

3. take by weighing (the being accurate to 0.0001g) sample about 5 grams, put into plastic cup, and add 200 ml distilled waters, after the vigorous agitation, cover and soaked 24 hours.

4. with qualitative filter paper solution is filtered, pipette filtrate with transfer pipet and put into Erlenmeyer flask for 50 milliliters, solution becomes redness drip a phenolphthalein indicator in extracting solution after, drips till the extremely red disappearance just of an amount of salpeter solution (1+3), and promptly the pH value of extracting solution is adjusted to 7～8.In extracting solution, drip 10～12 5% potassiumchromate indicator then,, shake while dripping with the standard silver nitrate solution titration of 0.02N, until solution occur not disappearing orange red till.The standard silver nitrate solution milliliter number (V that record is consumed ₁), measure the consumption (V of blank test Silver Nitrate standardized solution simultaneously ₂).

(3) test-results is calculated

The soluble chloride ion content calculates according to following formula in the concrete:

$W_{{\mathrm{Cl}}^{-}}=\frac{C_{\left({\mathrm{AgNO}}_3\right)}(V_1-V_2)\&times;0.03545}{m_s\&times;50.00/250.0}\&times;100$

In the formula:

The mass percent of chlorion in the concrete;

C _(AgNO3)The amount of substance concentration of-Silver Nitrate standardized solution, mol/l;

V ₁The consumption of-Silver Nitrate standardized solution, ml;

V ₂The consumption of-blank test Silver Nitrate standardized solution, ml;

0.03545-the mmole quality of chlorion, g/mmol;

m _sThe quality of-concrete sample, g.

3. concrete resistance of chloride ion penetration energy

Concrete mix is shown in table 1-23.

Table 1-23 concrete mix

(1) concrete different depths chloride ion content

The soluble chlorine ion content is shown in table 1-24 on the concrete different depths.

Soluble chlorine ion content on the table 1-24 different depths

^*Annotate: 1.G is a different depths concrete layer institute sample thief quality;

2.V ₁Be the 0.02N standard silver nitrate liquor capacity that consumes;

3.0 the chloride ion content Cs the on～2mm degree of depth obtains by the function match.

(2) the concrete different depths chloride ion content regularity of distribution

Adopt " single order decaying exponential function ", among the his-and-hers watches 1-26 on the different depths soluble chlorine ion content testing data carry out match, the gained fitting parameter is listed in table 1-25, the chloride ion content matched curve of different depths as shown in Figure 5.

$y={\mathrm{<figure-callout\; id="0"\; label="y"\; filenames="A2009100082720048H1.png,A2009100082720048H2.png"\; state="\{\{state\}\}">y</figure-callout>}}_0+A_1\&CenterDot;e^{\frac{-\mathrm{<figure-callout\; id="1"\; label="x\; t"\; filenames="A2009100082720049H2.png"\; state="\{\{state\}\}">x</figure-callout>}}{t_{}}}$

In the formula:

A ₁Be intensity factor;

t ₁Be decay factor.

Table 1-25 concrete chloride ion content curve fitting parameter

Annotate: R is a correlation parameter.

By table 1-25 testing data as can be known, the chloride ion content of concrete different depths is obeyed single order decaying exponential function shown in Figure 5, and has good dependency, and correlation parameter R is all more than 0.99.

As shown in Figure 5, on the same degree of depth, the concrete chloride ion content of Adding Mineral Admixtures significantly is lower than the concrete of not mixing mineral admixture, and maximum can reduce by 40%, and the concrete opposing chlorion erosive ability of Adding Mineral Admixtures is better than not mixing the concrete of mineral admixture.The major cause that flyash and slag improve concrete resisting chloride ion penetration diffusibility is, the complex effects such as closely knit filling of flyash and scoriaceous active effect and concrete corrosion-prevention rust-resistance penetration-resistant agent are to the improvement of concrete hole structure, diffusion admittance has not only been blocked in nano level sodium bentonite suction diffusion in the concrete corrosion-prevention rust-resistance penetration-resistant agent, make the connective variation of concrete hole, the hole tortuosity increases, improved the ability of resisting chloride ion penetration diffusion, concrete corrosion-prevention rust-resistance penetration-resistant agent can adsorb the free chloro ion that enters from concrete surface penetration in addition, make it to be converted into insoluble complex, thereby the chlorion diffusion is constantly descended.

(3) concrete chloride ion spread coefficient

Research to concrete resisting chloride ion penetration performance, generally adopt the chlorion apparent diffusion coefficient as controlling index, in this test, adopt " the self-defined nonlinear fitting function " function among the software for calculation origin, analytic solution according to Fick second law, carry out non-linear regression with the data among the method for least squares his-and-hers watches 1-24, and try to achieve concrete surface chlorine ion concentration Cs and chlorion apparent diffusion coefficient Da, gained the results are shown in table 1-24 and table 1-26.

The concrete chlorion apparent diffusion coefficient of table 1-26 Da * 10 ^-12/ m ²/ s

According to the chloride diffusion coefficient standard that Mr. Tang Luping proposes, chlorion apparent diffusion coefficient Da＜8 * 10 ^-12m ²During/s, the concrete resistance of chloride ion penetration can be better; Chlorion apparent diffusion coefficient Da＜2 * 10 ^-12m ²During/s, the concrete resistance of chloride ion penetration can be very good.Testing data by table 1-28 shows concrete Da＜2 * 10 of admixture complex mineral blending material and concrete corrosion-prevention rust-resistance penetration-resistant agent ^-12m ²/ s, concrete have extraordinary resistance of chloride ion penetration energy, can satisfy Da≤3.0 * 10 ^-12m ²The engine request of/s.

The remarkable reduction of concrete chloride ion apparent diffusion coefficient of admixture complex mineral blending material and concrete corrosion-prevention rust-resistance penetration-resistant agent mainly is because diffusion admittance has not only been blocked in nano level sodium bentonite suction diffusion in the shape effect that complex mineral blending material exists and micro aggregate effect and the concrete corrosion-prevention rust-resistance penetration-resistant agent, make the connective variation of concrete hole, therefore, can significantly improve concrete anti-Cl ^-Erosional competency.

1.2.9 concrete antifreezing Journal of Sex Research

The test of concrete antifreezing performance:

Concrete mix and correlation parameter thereof that test is adopted see Table 1-16.

1. the scope of application

Present method is applicable in water measures concrete anti-freezing property through fast freeze-thaw.The index available energy of rapid method anti-freezing property stands fast freeze-thaw round-robin number of times or durability factor is represented.

Present method is specially adapted to the demanding concrete of frost resistance.

2. testing installation

(1) fast freeze-thaw device: it is motionless that test specimen is rested in the water, rely on heat exchanger fluid temperature variation and continuously, automatically according to the 5th freeze thawing device that requirement is carried out of present method testing sequence.The extreme difference of each point temperature must not be above 2 ℃ in the freeze thawing case during full-load running.

(2) test specimen box: make by the steel plate that 1～2mm is thick.Its net section size should be 110 * 110 (mm), and height should exceed 50～100mm than test specimen.The interior water surface of back box has been filled up in the test specimen bottom should can exceed test specimen end face 5mm at least.

(3) counter scale: weighing 10kg, sensibility reciprocal 5g, or weighing 20kg, sensibility reciprocal 10g.

(4) dynamic modulus of elasticity determinator: resonant method dynamic modulus of elasticity determinator.

(5) thermopair, potentiometer: in 20～-20 ℃ of scopes, measuring core temperature.Measuring accuracy is not less than ± and 0.5 ℃.

3. testing sequence

(1) test specimen should begin freezing and thawing test at 28d during the length of time.4d takes out test specimen from curing room before the freezing and thawing test, carries out visual inspection, soaks (comprising the thermometric test specimen) then in temperature is 15～20 ℃ water.The water surface exceeds test specimen water surface 20mm at least during immersion, and test specimen carries out freezing and thawing test after soaking 4d.

(2) after immersion finishes, take out test specimen, visit except that surface-moisture, weigh, and measure the initial value of its horizontal fundamental frequency by the regulation of this standard dynamic modulus of elasticity test with wet cloth.

(3) test specimen is put into the test specimen box, in order to make test specimen be subjected to temperature balanced, and the additional pressure of freezing and causing because of moisture around the elimination test specimen, the side of test specimen and bottom pad are put the rubber plate of proper width and thickness, in entire test, elevation of water surface remains and exceeds about test specimen end face 5mm in the box.

(4) the test specimen box is put into the freeze thawing case.The test specimen box that the thermometric test specimen wherein is housed is placed on the central position of freeze thawing case, and can begin freeze-thaw cycle this moment.

(5) the freeze-thaw cycle process meets the following requirements:

1. each freeze-thaw cycle is finished in 2～4h, and the time that wherein is used to melt is no less than 1/4 of the whole freeze thawing time.

2. freezing and melting at the end, the test specimen core temperature is controlled at-17 ± 2 ℃ and 8 ± 2 ℃ respectively.

3. every test specimen is reduced to-15 ℃ of used times from 6 ℃ and is no less than 1/2 of freeze-off time.Every test specimen rises to 6 ℃ of used times from-15 ℃ also must not be less than 1/2 of the whole thawing time, and the inside and outside temperature difference of test specimen is no more than 28 ℃.

4. be no more than 10min the switching time between freezing and melting.

(6) test specimen is done once laterally fundamental frequency measurement every 25 circulations, before measuring the test specimen surface scum is cleaned up, and wipes surface area water, and checks that its outside exergy dissipation injures mass loss.The measuring method of horizontal fundamental frequency and the regulation that step is pressed elasticity modulus test are carried out.After having surveyed, promptly test specimen is fallen a stature and reload in the test specimen box.The measurement of test specimen, weighing and visual inspection are rapid as far as possible, in order to avoid moisture loss.

The temperature-stable equilibrium when some test specimen stops freezing taking-up, is filled the room with test specimen in addition when (7) freezing in cold liquid for the assurance test specimen.

(8) freeze thawing arrive one of following 3 kinds of situations promptly stop the test:

1. 300 circulations have been reached;

2. relative dynamic elastic modulus drops to below 60%;

3. mass loss rate reaches 5%.

4. test-results is calculated

(1) relative dynamic elastic modulus of concrete sample:

$P=\frac{f_n^2}{{\mathrm{<figure-callout\; id="2"\; label="f\; o"\; filenames="A2009100082720049H2.png"\; state="\{\{state\}\}">f</figure-callout>}}_o^{}}\&times;100$

In the formula:

The relative dynamic elastic modulus of P------test specimen behind n freeze-thaw cycle is with the mean value calculation (%) of three test specimens;

f _n--the horizontal fundamental frequency (Hz) of test specimen behind----n freeze-thaw cycle;

f _o--the horizontal fundamental frequency initial value of the test specimen that----records before the freezing and thawing test (Hz).

(2) mass loss rate after the concrete sample freeze thawing:

$\mathrm{\&Delta;}{W}_n=\frac{G_0-{\mathrm{<figure-callout\; id="0"\; label="G\; n\; G"\; filenames="A2009100082720048H1.png,A2009100082720048H2.png"\; state="\{\{state\}\}">G</figure-callout>}}_n}{G_{}}\&times;100$

In the formula:

Δ W _n--mass loss rate of test specimen behind----n freeze-thaw cycle is with the mean value calculation (%) of 3 test specimens;

G _o--the test specimen quality (kg) before----freezing and thawing test;

G _n--the test specimen quality (kg) behind----n freeze-thaw cycle.

(3) the anti-fast freeze-thaw cycle index of concrete with satisfy simultaneously the relative dynamic elastic modulus value reach 60% and the mass loss rate maximum cycle that is no more than at 5% o'clock represent.

(4) the concrete durability coefficient is calculated as follows:

DF＝P×n/300

In the formula:

DF------concrete durability index;

N------reaches it (8) freezing-thawing cycles when requiring of this section testing sequence;

The relative dynamic elastic modulus of P------test specimen behind n freeze-thaw cycle.

5. concrete dynamic modulus of elasticity test

(1) scope of application

Present method is applicable to measures concrete dynamic modulus of elasticity, the degree that after standing unfreezing, wrecks with the check concrete, and evaluate durability of concrete with this.

(2) test material preparation

It is the prism test specimen of 100 * 100 (mm) that the cross section is adopted in this test, and its depth-width ratio is 5.

(3) testing installation

1. resonant method concrete dynamic modulus of elasticity determinator;

The output frequency variable range is 100～20000Hz, and output rating should be able to encourage test specimen to produce forced vibration, so that can make the fundamental vibration frequency (fundamental frequency) of test specimen with the principle of resonance.

2. testing sequence

(1) quality and the size of mensuration test specimen.The measuring accuracy of test specimen quality should be in ± 0.5%, and the measuring accuracy of size should be in ± 1%.The length of each test specimen and sectional dimension are all got the mean value that 3 positions are measured.

(2) test specimen is placed on the supporting mass, and makes the position of transverter and acceptance point.

(3) the exciting power of the instrument of adjustment resonance earlier and receiving gain knob are to the appropriate location, the conversion excited frequency is noted the needle deflection of observation index ammeter simultaneously, when needle deflection is maximum, represent that promptly test specimen reaches resonance state, at this moment shown exciting rate is the fundamental vibration step rate of test specimen.Each measurement repeats to survey and reads more than twice, is no more than 0.5% as the difference of twice continuous measured value, gets the test result of the mean value of these two measured values as this test specimen.

6. test-results is calculated

The concrete dynamic modulus of elasticity is calculated as follows:

$E_d=9.46\&times;{10}^{-4}\frac{W{l}^3{f}^2}{a^4}\&times;K$

In the formula:

The concrete dynamic modulus of elasticity of Ed----(MPa);

The length of side (mm) of a------square sectional test specimen;

The length of L------test specimen (mm);

W-----test specimen quality (kg);

Basic vibration frequency (Hz) during f------test specimen transverse vibration;

K------sample dimensions correction factor:

During L/a=5, k=1.26

The concrete dynamic modulus of elasticity, calculates and is accurate to 100MPa as test-results with the mean value of 3 test specimens, and its test-results is listed in table 1-27.

The concrete freeze-thaw resistance of table 1-27

1.2.10 concrete thermal insulation warming research

1. thermal insulation warming Analysis on Mechanism

Concrete owing to the hydration reaction of gelling material produces a large amount of hydration heat, concrete internal temperature is raise rapidly, and concrete heat-conductive characteristic is lower in process of setting, and thermal conductivity is 7.66 * 10 ^-7～9.58 * 10 ^-7m ²/ s, when volume of concrete was big, inside concrete was approximately adiabatic condition, and heat distributes very slow, makes the tangible temperature difference of the inside and outside formation of concrete, thereby causes the distortion of concrete ectonexine inconsistent, produces thermal stress.When thermal stress surpassed concrete ultimate tensile strength, concrete surface will produce the crack, and concrete globality, weather resistance and even security are caused detrimentally affect.

2. test results and analysis

Mix proportion is listed in table 1-28, and inside concrete measuring point thermal insulation warming value is listed in table 1-29 and table 1-30, and concrete thermal insulation warming change curve as shown in Figure 6.

Table 1-28 concrete mix

Annotate: cement adopts scenery with hills and waters P.O 42.5R.

Table 1-29 inside concrete measuring point thermal insulation warming value/℃

The continuous table of going up

The conventional inside concrete measuring point of table 1-30 thermal insulation warming value/℃

The continuous table of going up

As seen from Figure 6, mix the concrete corrosion-prevention rust-resistance penetration-resistant agent concrete and mix and stir back 45h, the internal insulation temperature rise reaches 31 ℃ of peak values, and keeps this state to occur temperature reduction phenomenon in about 15 hours afterwards, and peak temperature and drop temperature difference are 18 ℃.The testing data of Yang Rongjun and Hu Liping shows, often appear at concrete for its exothermic peak of conventional concrete of same type and mix and stir between the 15～20h of back, and its peak value reaches about 45 ℃.Mix concrete corrosion-prevention rust-resistance penetration-resistant agent concrete exothermic peak time of occurrence and postpone about 25～30h, and its peak temperature is hanged down about 16 ℃ than conventional concrete.It is comparatively mild to mix concrete corrosion-prevention rust-resistance penetration-resistant agent concrete thermal insulation warming change curve, shows that the more conventional concrete of its rate of heat release is little, and whole exothermic process is elongated.Mix concrete corrosion-prevention rust-resistance penetration-resistant agent concrete hydrating speed characteristic comparatively uniformly, make sclerosis back microstructure more closely knit, the structure internal-external temperature difference is littler, has reduced the thermal cracking that causes because of the temperature difference, and this is highly beneficial for building of mass concrete member.

Mix concrete corrosion-prevention rust-resistance penetration-resistant agent and can reduce the thermal insulation warming of inside concrete significantly, mainly be because concrete corrosion-prevention rust-resistance penetration-resistant agent has good delayed coagulation, delay cement initial stage aquation, make early stage hydrated cementitious thermal discharge less, thereby reduced because the thermal stress that internal-external temperature difference causes, prevent the generation of concrete thermal cracking, guaranteed the concrete structure overall integrity.

3. temperature stress calculation

Mix the concrete corrosion-prevention rust-resistance penetration-resistant agent concrete, can avoid temperature difference crack, the underlying cause effectively is that concrete thermal stress is lower than concrete tensile strength.Reference literature ^[57]In Thermal Calculation Method, calculate and to mix herein the concrete corrosion-prevention rust-resistance penetration-resistant agent concrete pouring 2d length of time, the temperature shrinkage stress when promptly internal temperature reaches warm peak.

(1) E _(t)＝E ₀(1-e ^-0.09×t)

In the formula:

E _(t)-regulation age concrete Young's modulus, N/mm ²

E ₀-concrete final Young's modulus, N/mm ², approximate value is 3.0 * 10 ⁴

Calculate: E ₍₂₎=3.0 * 10 ⁴* (1-2.718 ^{-0.09 * 2})=4.9 * 10 ³

(2) ΔT＝T _(t)+T ₀-T _h

In the formula:

The comprehensive temperature difference of the concrete maximum of T-, ℃;

T _(t)-hydration heat of concrete thermal insulation warming value, by test T ₍₂₎=32 ℃;

T ₀-concrete molding temperature, by above-mentioned test T ₀=15 ℃;

T _hThe equilibrium temperature that reaches after-the concrete placement, general getting according to climatological data over the years worked as average temperature of the whole year, and area, Qingdao average temperature of the whole year is 12.3 ℃.

Calculate: T=32+15-12.3=34.7 ℃.

(3) $\mathrm{\&sigma;}=\frac{E_{\left(t\right)}\&times;a\&times;\mathrm{\&Delta;T}}{1-v}\&times;S_{\left(t\right)}\&times;R$

In the formula:

The concrete temperature string stress in σ-regulation length of time, N/mm ²

The coefficient of relaxation that S (t)-consideration is crept and influenced generally is taken as 0.3～0.5;

The concrete outer constraint factor of R-gets 0.25～0.5;

The concrete Poisson's ratio of v-generally gets 0.15～0.20.

The concrete linear expansivity of a-generally is taken as 1.0 * 10 ^-5

Calculate:

$\mathrm{\&sigma;}=\frac{4.9\&times;{10}^3\&times;1.0\&times;{10}^{-5}\&times;34.7}{1-0.2}\&times;0.4\&times;0.5=0.43N/{\mathrm{<figure-callout\; id="2"\; label="mm"\; filenames="A2009100082720049H2.png"\; state="\{\{state\}\}">mm</figure-callout>}}^2$

(4) ${\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="A2009100082720049H2.png"\; state="\{\{state\}\}">f</figure-callout>}}_2=f_{28}\&CenterDot;\frac{\mathrm{<figure-callout\; id="2"\; label="lg"\; filenames="A2009100082720049H2.png"\; state="\{\{state\}\}">lg</figure-callout>}2}{\lg 28}$

In the formula:

f ₂The ultimate compression strength of-2d age concrete, MPa;

f ₂₈The ultimate compression strength of-28d age concrete, MPa;

Calculate: f ₂=41.7 * 0.3/1.447=8.76MPa

Under the usual condition, tensile strength only is 1/10 of ultimate compression strength, so concrete tensile strength is 8.76 * 1/10=0.88Mpa＞0.43MPa.

Can get by aforementioned calculation, mix the thermal stress of concrete corrosion-prevention rust-resistance penetration-resistant agent concrete 2d during the length of time, can guarantee that mass concrete does not ftracture, thereby effectively improve the corrosion resistance and the endurance quality of concrete structures less than tensile strength.

Description of drawings

Fig. 1 is that concrete corrosion-prevention rust-resistance penetration-resistant agent is to continuous current, current potential-time curve analysis chart in the steel bar corrosion influence test;

Continuous current when Fig. 2 is the admixture concrete corrosion-prevention rust-resistance penetration-resistant agent, current potential-time plot;

Continuous current when Fig. 3 is admixture concrete corrosion-prevention rust-resistance penetration-resistant agent and NaCl, current potential-time plot;

Fig. 4 is a concrete flash carbonization graphic representation in the anti-carbonization test;

Fig. 5 is the chloride ion content matched curve figure of concrete different depths during resistance of chloride ion penetration can be tested;

Fig. 6 is a concrete thermal insulation warming change curve in the research of concrete thermal insulation warming;

Embodiment

Embodiment 1:

Concrete corrosion-prevention rust-resistance penetration-resistant agent of the present invention comprises following compositions in weight portion:

Methanonaphthalene sodium sulfonate 0.8 gram

Compound suds-stabilizing agent 0.015 gram of rosined soap

Sodium bentonite 0.6 gram

Calcium nitrite 1.0 grams

Vitriol complexing agent 1.055 grams

Organosilane mixture 0.53 gram.。

Wherein, the methanonaphthalene sodium sulfonate is as efficient diminishing component; Because there is many successive capillary-size pore in concrete own characteristic at inside concrete, thereby make corrosive medium, quicken the corrosion of cement stone very easily by hole invasion water mudstone inside.The admixture high efficiency water reducing agent can guarantee that concrete mix has under the prerequisite of good operation, reduces the W/C value of concrete mix, i.e. the content of coagulation water in soil.Reduce pore quantity, improve pore structure, strengthen concrete degree of compactness, thereby reduce the infiltration rate of chlorion, delay rusting rate, improve concrete corrosion resistance and weather resistance.

The compound suds-stabilizing agent of rosined soap is as the bleed component; The effect of air entrapment agent is to make concrete mix produce many small independently CABs in whipping process, because the obstruct of bubble, make the complications that free evaporation of water route becomes in the concrete mix, tiny, dispersion, thereby quantity capillaceous and characteristic have been changed, concrete maturing and frost resistance are significantly improved, the possibility that concrete inner structure is damaged significantly reduces, and hinders the infiltration of corrosive mediums such as extraneous chlorion simultaneously.

Calcium nitrite or nitrous acid cyclohexane give use for resistance rust component; One of main reason that the Steel Concrete weather resistance that the corrosion and destruction of reinforcing bar is considered to cause at present reduces is so at the safeguard procedures of steel bar corrosion, also be an importance that improves the Steel Concrete weather resistance.Mix rust inhibitor improving on the basis of concrete density, be considered to one of the simplest, economy and otherwise effective technique measure.Rust inhibitor is passivator and oxide film healant, and it can impel rebar surface to produce one deck with Υ-Fe ₂O ₃Or Fe ₃O ₄Being the main oxide passivation film of forming, this film thickness is about 20～

And the defective of repairing rebar surface, whole reinforcing bar is wrapped up by one deck oxide passivation film, compactness is fine, can stop chlorion to penetrate, and reduces the free speed of iron ion, thereby reaches antirust purpose.

The vitriol complexing agent is as antiseptic ingredient, it can with the vitriol generation chemical reaction that infiltrates in the concrete, generate the complex compound of no volumetric expansion, and by means of outside the diffusion discharge concrete body; Because the medium of skeleton construction outside is corrosion concrete at first, influences reinforcing bar by concrete then.In fact for reinforcing bar, concrete promptly is a kind of medium of decision reinforcement property.So the antiseptic power that improves concrete self is to guarantee that reinforcing bar avoids the primary condition of corrosion.Can cause the external agency of concrete erosion that contained CO in acid soil and soil or the underground water is arranged ₂, HCO ₃ ^-, SO ₄ ^2-, Cl ^-, Mg ²⁺, NH ₄ ⁺Deng, wherein, Cl ^-Direct corrosion reinforcing bar, remaining then first corrosion concrete finally also causes steel bar corrosion, SO ₄ ^2-Also can directly influence steel bar corrosion when content is high.Admixture sanitas in concrete can improve the antiseptic power of concrete self, thereby slows down the corrosion to reinforcing bar.This is because sanitas can be combined to insoluble salt or complex compound with objectionable impurities, and leaches from concrete by means of diffusion.In addition, sanitas can also suppress Cl ^-Activation or quicken Cl ^-Be combined to the hydration calcium chloroaluminate of indissoluble, thereby slow down its direct influence, also improve the antiseptic power of concrete self reinforcing bar.Sodium bentonite can cut off the successive pore as impervious component, significantly improves concrete degree of compactness, thereby reduces water and aggressive liquids infiltration significantly.In maturing, there are defectives such as many pores, microfracture, increased concrete perviousness.

The organosilane mixture of admixture density impervious agent in concrete, it is after concrete hardening, water-repellent layer is dissolved by alkaline matter gradually, moisture in the wilkinite absorptive hair pore or the planar water on the cement particle surface produce and expand, fill pore and micro gap, significantly increase density, impermeability, anti-carbonization and the anti-drying shrinkage of maturing, and reduce Ca (OH) in the concrete significantly ₂Solubility and the invasive of extraneous corrosive medium, thereby improve concrete resistance to corrosion.

Above-mentioned each component is coordinated mutually, promotes mutually, makes the performance of concrete corrosion-prevention rust-resistance penetration-resistant agent be tending towards perfect.

Above-mentioned each component drying, pulverizing, mixing are promptly become concrete corrosion-prevention rust-resistance penetration-resistant agent later on.

The weather resistance of concrete structure is meant that structure is resisted external environment in its use or self produces the ability of erosion damage, and the destruction of the weather resistance of concrete structure is meant structure properties degradation phenomena in time.From producing weather resistance destructive immediate cause, the reason of concrete structure durability destruction can be divided into inner reason and external cause two portions.The inner reason of concrete structures weather resistance destructive is meant some defectives of concrete self.Concrete is complicated heterogeneous complex group architectonical, and inside exists a large amount of kapillaries, hole and tiny crack etc., and these defectives become the passage of external corrosion medium to internal divergence.In addition, from concrete self composition material angle, the admixture villaumite also is a kind of defective in concrete, because the existence of chlorion will make steel bars in concrete produce corrosion.Concrete structures weather resistance destructive external cause mainly is meant the deterioration that physical environment and environment for use cause, makes the concrete neutralisation as carbonic acid gas etc., impels reinforcing bars rusting, and the salt in the ocean environment causes concrete erosion and steel bar corrosion etc.

Improve the corrosion resistance and the weather resistance of concrete structures, should take measures from two aspects of deterioration effect that reduce concrete subsurface defect and reduction external environment.Concrete corrosion-prevention rust-resistance penetration-resistant agent of the present invention is just from adopting high efficiency water reducing agent, air-entrained agent, admixture rust inhibitor, admixture sanitas, admixture density impervious agent etc. to embody this guiding theory by all kinds of means.

Embodiment 2:

Concrete corrosion-prevention rust-resistance penetration-resistant agent of the present invention comprises following compositions in weight portion:

Methanonaphthalene sodium sulfonate 0.6 gram

Compound suds-stabilizing agent 0.01 gram of rosined soap

Sodium bentonite 0.5 gram

Nitrous acid bicyclohexane 0.9 gram

Vitriol complexing agent 1.0 grams

Organosilane mixture 0.5 gram.

The present embodiment other parts are identical with embodiment 1.

Embodiment 3:

Concrete corrosion-prevention rust-resistance penetration-resistant agent of the present invention comprises following compositions in weight portion:

Methanonaphthalene sodium sulfonate 1.0 grams

Compound suds-stabilizing agent 0.02 gram of rosined soap

Sodium bentonite 0.7 gram

Nitrous acid bicyclohexane 1.1 grams

Vitriol complexing agent 1.1 grams

Organosilane mixture 0.6 gram.

The present embodiment other parts are identical with embodiment 1.

Claims (2)

1, concrete corrosion-prevention rust-resistance penetration-resistant agent is characterized in that comprising following compositions in weight portion:

Methanonaphthalene sodium sulfonate 0.6-1.0 gram

The compound suds-stabilizing agent 0.01-0.02 gram of rosined soap

Sodium bentonite 0.5-0.7 gram

Calcium nitrite or nitrous acid bicyclohexane 0.9-1.1 gram

Vitriol complexing agent 1.0-1.1 gram

Impervious component 0.5-0.6 gram.

2, concrete corrosion-prevention rust-resistance penetration-resistant agent according to claim 1 is characterized in that: described impervious component is the organosilane mixture.

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