CN113603421A - Impervious recycled concrete and preparation method thereof - Google Patents
Impervious recycled concrete and preparation method thereof Download PDFInfo
- Publication number
- CN113603421A CN113603421A CN202110972029.6A CN202110972029A CN113603421A CN 113603421 A CN113603421 A CN 113603421A CN 202110972029 A CN202110972029 A CN 202110972029A CN 113603421 A CN113603421 A CN 113603421A
- Authority
- CN
- China
- Prior art keywords
- hydrotalcite
- aggregate
- recycled concrete
- recycled
- terminated polysiloxane
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000004567 concrete Substances 0.000 title claims abstract description 98
- 238000002360 preparation method Methods 0.000 title claims abstract description 39
- GDVKFRBCXAPAQJ-UHFFFAOYSA-A dialuminum;hexamagnesium;carbonate;hexadecahydroxide Chemical class [OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[Mg+2].[Mg+2].[Mg+2].[Mg+2].[Mg+2].[Mg+2].[Al+3].[Al+3].[O-]C([O-])=O GDVKFRBCXAPAQJ-UHFFFAOYSA-A 0.000 claims abstract description 103
- -1 polysiloxane Polymers 0.000 claims abstract description 63
- 229920001296 polysiloxane Polymers 0.000 claims abstract description 53
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 52
- 239000003638 chemical reducing agent Substances 0.000 claims abstract description 16
- 239000004568 cement Substances 0.000 claims abstract description 14
- 230000003487 anti-permeability effect Effects 0.000 claims abstract description 11
- 239000002994 raw material Substances 0.000 claims abstract description 9
- 239000011398 Portland cement Substances 0.000 claims abstract description 8
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 4
- 229960001545 hydrotalcite Drugs 0.000 claims description 41
- 229910001701 hydrotalcite Inorganic materials 0.000 claims description 41
- 239000000839 emulsion Substances 0.000 claims description 13
- 125000002887 hydroxy group Chemical group [H]O* 0.000 claims description 13
- 238000003756 stirring Methods 0.000 claims description 12
- 239000002245 particle Substances 0.000 claims description 11
- 239000008367 deionised water Substances 0.000 claims description 9
- 229910021641 deionized water Inorganic materials 0.000 claims description 9
- 238000002156 mixing Methods 0.000 claims description 9
- 238000000034 method Methods 0.000 claims description 8
- 229920005646 polycarboxylate Polymers 0.000 claims description 8
- 238000006243 chemical reaction Methods 0.000 claims description 6
- 238000010438 heat treatment Methods 0.000 claims description 6
- 238000004321 preservation Methods 0.000 claims description 6
- 238000005303 weighing Methods 0.000 claims description 6
- 238000007605 air drying Methods 0.000 claims description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 abstract description 13
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 abstract description 11
- 238000001179 sorption measurement Methods 0.000 abstract description 11
- 150000002500 ions Chemical class 0.000 abstract 1
- 230000000052 comparative effect Effects 0.000 description 12
- 238000012360 testing method Methods 0.000 description 12
- 230000000694 effects Effects 0.000 description 11
- 230000035515 penetration Effects 0.000 description 11
- 150000001450 anions Chemical class 0.000 description 7
- 239000011148 porous material Substances 0.000 description 7
- 239000004205 dimethyl polysiloxane Substances 0.000 description 6
- 229920000435 poly(dimethylsiloxane) Polymers 0.000 description 6
- 239000004576 sand Substances 0.000 description 6
- 239000013535 sea water Substances 0.000 description 6
- 125000001931 aliphatic group Chemical group 0.000 description 5
- 238000006703 hydration reaction Methods 0.000 description 5
- PWZFXELTLAQOKC-UHFFFAOYSA-A dialuminum;hexamagnesium;carbonate;hexadecahydroxide;tetrahydrate Polymers O.O.O.O.[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[Mg+2].[Mg+2].[Mg+2].[Mg+2].[Mg+2].[Mg+2].[Al+3].[Al+3].[O-]C([O-])=O PWZFXELTLAQOKC-UHFFFAOYSA-A 0.000 description 4
- 238000011049 filling Methods 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 239000004575 stone Substances 0.000 description 4
- 239000008030 superplasticizer Substances 0.000 description 4
- 239000002699 waste material Substances 0.000 description 4
- 239000003153 chemical reaction reagent Substances 0.000 description 3
- 230000007797 corrosion Effects 0.000 description 3
- 238000005260 corrosion Methods 0.000 description 3
- 238000001514 detection method Methods 0.000 description 3
- 230000035699 permeability Effects 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 238000012216 screening Methods 0.000 description 3
- SCPYDCQAZCOKTP-UHFFFAOYSA-N silanol Chemical compound [SiH3]O SCPYDCQAZCOKTP-UHFFFAOYSA-N 0.000 description 3
- 230000004580 weight loss Effects 0.000 description 3
- 230000009471 action Effects 0.000 description 2
- 230000036571 hydration Effects 0.000 description 2
- 239000011229 interlayer Substances 0.000 description 2
- 230000009545 invasion Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 230000035484 reaction time Effects 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 238000007493 shaping process Methods 0.000 description 2
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- 229920000049 Carbon (fiber) Polymers 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 235000011114 ammonium hydroxide Nutrition 0.000 description 1
- 150000001449 anionic compounds Chemical class 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000011449 brick Substances 0.000 description 1
- 239000004566 building material Substances 0.000 description 1
- 239000004917 carbon fiber Substances 0.000 description 1
- MMCOUVMKNAHQOY-UHFFFAOYSA-N carbonoperoxoic acid Chemical group OOC(O)=O MMCOUVMKNAHQOY-UHFFFAOYSA-N 0.000 description 1
- 239000011083 cement mortar Substances 0.000 description 1
- 238000013329 compounding Methods 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 238000006482 condensation reaction Methods 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 125000001301 ethoxy group Chemical group [H]C([H])([H])C([H])([H])O* 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 230000002209 hydrophobic effect Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000011065 in-situ storage Methods 0.000 description 1
- 230000008595 infiltration Effects 0.000 description 1
- 238000001764 infiltration Methods 0.000 description 1
- 229910001412 inorganic anion Inorganic materials 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 239000010410 layer Substances 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 230000005012 migration Effects 0.000 description 1
- 238000013508 migration Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 229920002239 polyacrylonitrile Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 150000008130 triterpenoid saponins Chemical class 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 230000003313 weakening effect Effects 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
- C04B28/02—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing hydraulic cements other than calcium sulfates
- C04B28/04—Portland cements
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B14/00—Use of inorganic materials as fillers, e.g. pigments, for mortars, concrete or artificial stone; Treatment of inorganic materials specially adapted to enhance their filling properties in mortars, concrete or artificial stone
- C04B14/02—Granular materials, e.g. microballoons
- C04B14/36—Inorganic materials not provided for in groups C04B14/022 and C04B14/04 - C04B14/34
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B20/00—Use of materials as fillers for mortars, concrete or artificial stone according to more than one of groups C04B14/00 - C04B18/00 and characterised by shape or grain distribution; Treatment of materials according to more than one of the groups C04B14/00 - C04B18/00 specially adapted to enhance their filling properties in mortars, concrete or artificial stone; Expanding or defibrillating materials
- C04B20/02—Treatment
- C04B20/023—Chemical treatment
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
- C04B2111/20—Resistance against chemical, physical or biological attack
- C04B2111/2015—Sulfate resistance
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
- C04B2111/20—Resistance against chemical, physical or biological attack
- C04B2111/24—Sea water resistance
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
- C04B2111/20—Resistance against chemical, physical or biological attack
- C04B2111/27—Water resistance, i.e. waterproof or water-repellent materials
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2201/00—Mortars, concrete or artificial stone characterised by specific physical values
- C04B2201/50—Mortars, concrete or artificial stone characterised by specific physical values for the mechanical strength
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2201/00—Mortars, concrete or artificial stone characterised by specific physical values
- C04B2201/50—Mortars, concrete or artificial stone characterised by specific physical values for the mechanical strength
- C04B2201/52—High compression strength concretes, i.e. with a compression strength higher than about 55 N/mm2, e.g. reactive powder concrete [RPC]
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Inorganic Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Civil Engineering (AREA)
- Curing Cements, Concrete, And Artificial Stone (AREA)
Abstract
The invention discloses anti-permeability recycled concrete and a preparation method thereof. An impervious recycled concrete is prepared from the following raw materials: portland cement, fine aggregate, coarse aggregate, 110-144 parts of water, a water reducing agent, an air entraining agent and dihydroxy terminated polysiloxane modified hydrotalcite; the content of the recycled fine aggregate in the fine aggregate and the content of the recycled coarse aggregate in the coarse aggregate are both 20 to 80 weight percent. According to the application, gaps of the recycled aggregate are filled by using the dihydroxy terminated polysiloxane modified hydrotalcite, and meanwhile, the modified hydrotalcite can improve the compatibility among the natural aggregate, the recycled aggregate and the cement, so that the recycled concrete is compact in interior, the modified hydrotalcite has good adsorption and fixation performances on chloride ions, sulfate ions and other ions, and the impermeability of the recycled concrete is remarkably improved.
Description
Technical Field
The invention relates to the technical field of building materials, in particular to impervious recycled concrete and a preparation method thereof.
Background
With the rapid development of the building industry in China, the resource pressure is increasing day by day, and the recycling of wastes in the building industry is gradually paid attention by people. The gravel obtained by crushing the waste building is called recycled aggregate, and the recycled aggregate can be used for preparing concrete. The surface of the recycled aggregate is coated with the hardened cement mortar, so that the recycled aggregate has high apparent density, high water absorption and porosity, and chloride ions, sulfate ions and the like are easy to corrode concrete, so that the recycled concrete has poor durability.
The patent with the application number of CN201710231317.X discloses recycled concrete, which utilizes an air entraining agent to react with triterpenoid saponin, so that a large number of closed holes are formed in the concrete, and a hydrophobic membrane is formed on the surface of cement particles, so that the suction effect of capillaries is reduced, the penetration depth of the recycled concrete is measured, and the water penetration height of the recycled concrete is 20-30 mm.
The patent with the application number of CN201711112861.9 discloses a recycled concrete mixture and a preparation method and application thereof, the porosity of the recycled concrete mixture is reduced by adjusting the particle size range between recycled aggregate and natural aggregate, and the porosity of the recycled concrete mixture is reduced by filling the pores of the recycled concrete mixture with polypropylene fibers and polyacrylonitrile-based carbon fibers, so that the prepared recycled concrete is subjected to a penetration test, and the water penetration height is not lower than 13 mm.
When the recycled concrete in the related art is used in coastal areas, the concrete is in contact with seawater for a long time, and the seawater contains chloride ions and sulfate ions with certain concentration, so that the interior of the concrete is easily corroded, the seawater is more easily introduced into the concrete, the durability of the concrete is poor, and the impermeability of the concrete needs to be improved.
Disclosure of Invention
In order to improve the anti-permeability performance of recycled concrete, the application provides anti-permeability recycled concrete and a preparation method thereof.
In a first aspect, the application provides an impervious recycled concrete, which is realized by adopting the following technical scheme: the anti-permeability recycled concrete is prepared from the following raw materials in parts by weight:
the content of the recycled fine aggregate in the fine aggregate and the content of the recycled coarse aggregate in the coarse aggregate are both 20 to 80 weight percent.
By adopting the technical scheme, the fine aggregate and the coarse aggregate are both composed of the recycled aggregate and the natural aggregate with different particle sizes, and as various interface structures exist among the recycled aggregate, the natural aggregate and the cement, a large number of micropore pores exist in the recycled concrete, and the dihydroxy-terminated polysiloxane modified hydrotalcite added into the recycled concrete can improve the interface structure of the recycled concrete, and simultaneously fills the pores in the recycled concrete, so that the water permeability resistance of the recycled concrete is improved; in addition, the modified hydrotalcite has good adsorption and fixation performance on anions such as chloride ions, sulfate ions and the like, and improves the chloride ion permeation resistance and sulfate ion corrosion resistance of the recycled concrete;
the specific principle is as follows: one end of the dihydroxy terminated polysiloxane containing ethoxy is hydrolyzed into silanol, the hydrotalcite is hydroxyl carbonate of magnesium and aluminum, the hydrotalcite is assembled by a main body laminate with positive charges and interlayer anions through the interaction of non-covalent bonds, the hydrotalcite has a special layered structure, and the silanol is combined with the hydroxyl of the hydrotalcite, so that the surface of the modified hydrotalcite has a large number of hydroxyl; the modified hydrotalcite has high hydroxyl content, and can promote the compatibility of the recycled aggregate, the natural aggregate and the cement through hydrogen bond action and dehydration condensation reaction, thereby improving the interface structure of the recycled concrete, reducing the generation of pores inside the recycled concrete, weakening the capillary action inside the recycled concrete and improving the water-resistant permeability;
part of the dihydroxy terminated polysiloxane modified hydrotalcite is attached to the aggregate and migrates to the surface of the recycled concrete, so that the surface of the recycled concrete contains a large number of siloxane chain segments, has certain hydrophobicity, and the possibility of external moisture infiltration is further reduced; meanwhile, due to the special layered structure of the hydrotalcite, the interlayer binding force is weaker, so that the hydrotalcite has a better adsorption effect on inorganic anions in water, plays a better role in adsorption and fixation, reduces the penetration depth of chloride ions, and weakens the erosion effect of sulfate ions.
Preferably, the preparation method of the dihydroxy terminated polysiloxane modified hydrotalcite comprises the following steps: adjusting the pH value of deionized water to 8-10, adding hydrotalcite into the deionized water, wherein the weight ratio of the hydrotalcite to water is 1 (3-5), and preparing a hydrotalcite emulsion;
adding dihydroxy terminated polysiloxane into the hydrotalcite emulsion, wherein the weight ratio of the dihydroxy terminated polysiloxane to the hydrotalcite is 1 (0.2-0.4), heating to 35-45 ℃, and carrying out heat preservation reaction for 0.5-1.5 h to obtain the dihydroxy terminated polysiloxane modified hydrotalcite.
By adopting the technical scheme, the dihydroxy terminated polysiloxane is hydrolyzed in deionized water, silanol ends generated by hydrolysis and hydroxyl groups in the hydrotalcite are subjected to in-situ condensation, and dihydroxy terminated polysiloxane chain segments are grafted on the surface of the hydrotalcite to obtain the dihydroxy terminated polysiloxane modified hydrotalcite.
Preferably, the weight ratio of the dihydroxy-terminated polysiloxane to hydrotalcite is 1: 0.25.
Preferably, the hydroxyl content of the dihydroxy terminated polysiloxane is 7.5-8.5%.
By adopting the technical scheme, the higher the grafting rate of the dihydroxy terminated polysiloxane on the surface of the hydrotalcite is, the better the interface improvement effect on the recycled concrete is, but when the grafting rate is too high, the dihydroxy terminated polysiloxane is easy to be condensed, and the adsorption and fixation efficiency of the hydrotalcite on anions is reduced.
Preferably, the particle size of the hydrotalcite is 300-400 meshes.
By adopting the technical scheme, the mesh number of the hydrotalcite is increased, the particle size of the hydrotalcite is reduced, the specific surface area is increased, the adsorption capacity to anions is improved, meanwhile, the grafting ratio of the dihydroxy terminated polysiloxane and the hydrotalcite is increased, but when the particle size of the hydrotalcite is too small, agglomeration is easy to occur, and the adsorption effect of the modified hydrotalcite on the anions is influenced.
Preferably, the weight ratio of the cement to the water is 1: 0.3.
By adopting the technical scheme, the water-cement ratio of the recycled concrete is regulated, the cement hydration reaction time is shortened on the premise of full hydration of cement, the compactness of the concrete is improved, the pore structure is optimized to a certain extent, the early strength and the compactness of the recycled concrete are improved, and the anti-permeability performance of the recycled concrete is further improved.
Preferably, the water reducing agent is a polycarboxylate water reducing agent.
By adopting the technical scheme, the polycarboxylate water reducing agent plays a dispersing role, and the water reducing agent and the dihydroxy terminated polysiloxane modified hydrotalcite are compounded for use, so that on one hand, the workability of the recycled concrete can be improved, and on the other hand, part of the polycarboxylate water reducing agent is stored in the modified hydrotalcite due to the electrostatic adsorption effect of carboxylate ions and positive charge laminates of the modified hydrotalcite, and a slow release effect is played in the recycled concrete, so that the hydration reaction of the recycled concrete is sufficient, and the compressive strength and the density of the recycled concrete are further improved.
In a second aspect, the application provides a preparation method of impervious recycled concrete, which adopts the following technical scheme:
a preparation method of impervious recycled concrete comprises the following steps:
p1 and aggregate treatment: weighing dihydroxy-terminated polysiloxane modified hydrotalcite, fine aggregate and coarse aggregate according to the formula ratio, putting 40-60 wt% of dihydroxy-terminated polysiloxane modified hydrotalcite into deionized water to prepare modified hydrotalcite emulsion, putting the coarse aggregate and the fine aggregate into the modified hydrotalcite emulsion, stirring and mixing uniformly, heating to 50-60 ℃, carrying out heat preservation reaction for 1-2 h, and air-drying to obtain modified aggregate;
p2, preparation of recycled concrete: weighing Portland cement, water, a water reducing agent and an air entraining agent according to the formula ratio, adding the raw materials and the residual dihydroxy terminated polysiloxane modified hydrotalcite into modified aggregate, and stirring and blending to obtain the anti-permeability recycled concrete.
By adopting the technical scheme, the modified hydrotalcite fills gaps in the recycled aggregate, so that on one hand, the porosity of the recycled aggregate is reduced, the porosity in the recycled concrete is reduced, and the anti-permeability performance and the compressive strength of the recycled concrete are improved; on the other hand, the modified hydrotalcite can be fully dispersed and attached to the surface of the recycled aggregate, and effectively resists the invasion of chloride ions and sulfate ions.
Preferably, 54 to 55wt% of dihydroxy terminated polysiloxane modified hydrotalcite is taken from step P1 to treat coarse aggregate and fine aggregate.
Under the dosage range of the technical scheme, the filling effect of the modified hydrotalcite on the coarse and fine aggregates is optimal, and the filling effect of the modified hydrotalcite on the coarse and fine aggregates is almost not influenced if the dosage range is exceeded.
In summary, the present application has the following beneficial effects:
1. according to the application, the dihydroxy terminated polysiloxane is grafted on the surface of the hydrotalcite, so that the surface of the hydrotalcite contains a large amount of hydroxyl, the modified hydrotalcite improves the interface structure of the recycled concrete, the pores inside the recycled concrete are filled, the water-resistant permeability of the recycled concrete is improved, and meanwhile, due to the special layer structure of the modified hydrotalcite, the adsorption and fixation performances of anions such as chloride ions and sulfate ions are better.
2. This application is through regulating and control the water-cement ratio of recycled concrete, under the prerequisite of cement abundant hydration, shortens cement hydration reaction time, and the closely knit nature of concrete improves, has optimized pore structure to a certain extent, improves the early strength and the compactedness of recycled concrete, and the impervious performance of recycled concrete further improves.
3. According to the application, the polycarboxylate water reducing agent and the dihydroxy terminated polysiloxane modified hydrotalcite are compounded for use, so that on one hand, the workability of the recycled concrete can be improved, on the other hand, part of the polycarboxylate water reducing agent and the modified hydrotalcite play a slow release effect through an electrostatic adsorption effect, and the compression strength and the density of the recycled concrete are further improved.
4. According to the preparation method, the modified hydrotalcite is used for filling gaps in the recycled aggregate, so that on one hand, the porosity of the recycled aggregate is reduced, the porosity in the recycled concrete is reduced, and the anti-permeability performance of the recycled concrete is improved; on the other hand, the modified hydrotalcite can be fully dispersed and attached to the surface of the recycled aggregate, and effectively resists the invasion of chloride ions and sulfate ions.
Detailed Description
Unless otherwise specified, the raw material sources of the following preparation examples, examples and comparative examples are shown in table 1 below.
TABLE 1 sources of raw materials
The recycled aggregate is recovered from waste buildings in Yongjia county, Zhejiang, and the age is 1 year.
Preparation example of bishydroxy-terminated polysiloxane-modified hydrotalcite
Preparation example 1
A dihydroxy terminated polysiloxane modified hydrotalcite is prepared by the following steps:
adding 20wt% ammonia water into 30kg deionized water, adjusting pH to 8, slowly adding 10kg hydrotalcite (model is Lu-12, mesh number is 800) under stirring at 1200rpm, and making into hydrotalcite emulsion;
adding 50kg of dihydroxy terminated polydimethylsiloxane (with a hydroxyl value of 6-7%) into the hydrotalcite emulsion, heating to 35 ℃, reacting for 1.5 hours under heat preservation, filtering after the reaction is finished, washing with water, and drying in the air to obtain the dihydroxy terminated polysiloxane modified hydrotalcite.
Preparation examples 2 to 6
The dihydroxy terminated polysiloxane modified hydrotalcite is different from the hydrotalcite prepared in preparation example 1 in process parameters, and the specific process parameters are shown in table 2 below.
TABLE 2 Process parameters of bishydroxy terminated polysiloxane modified hydrotalcite
Preparation example 7
A dihydroxy terminated polysiloxane modified hydrotalcite is different from that of preparation example 6 in that hydrotalcite with 300-400 mesh is used as a substitute for hydrotalcite with 800 mesh.
Preparation examples 8 to 9
A bishydroxy-terminated polysiloxane-modified hydrotalcite which is different from that of preparation example 7 in the hydroxyl group content of the bishydroxy-terminated polydimethylsiloxane:
wherein, in preparation example 8, dihydroxyl-terminated polydimethylsiloxane with hydroxyl content of 6-7% is replaced by dihydroxyl-terminated polydimethylsiloxane with hydroxyl content of 10-12% by mass;
preparation example 9 bishydroxy-terminated polydimethylsiloxane having a hydroxyl group content of 6 to 7% was replaced with bishydroxy-terminated polydimethylsiloxane having a hydroxyl group content of 7.5 to 8.5% by mass.
Preparation example of recycled aggregate
The recycled aggregate is prepared by the following preparation method:
putting bricks of a waste building into a crusher for crushing to obtain recycled aggregate with the maximum particle size of not more than 31.5mm, putting the recycled aggregate into a 5X series gravel shaping machine production machine sand making device, wherein the linear speed of the 5X series gravel shaping machine production machine sand making device is 100m/s, carrying out primary rolling screening on the shaped recycled aggregate particles, and screening out recycled fine aggregate with the particle size of 3-5 mm and recycled coarse aggregate with the particle size of 5-16 mm after two times of screening.
Examples
Examples 1-9 each provide an impervious recycled concrete, and are described below with reference to example 1.
Example 1 provides an impervious recycled concrete, comprising the steps of:
p1, weighing 6kg of the dihydroxy terminated polysiloxane modified hydrotalcite prepared in preparation example 1, 13.6kg of natural sand, 23.2kg of crushed stone, 54.4kg of recycled fine aggregate and 92.8kg of recycled coarse aggregate;
2.4kg of dihydroxy terminated polysiloxane modified hydrotalcite is put into 30kg of deionized water to prepare modified hydrotalcite emulsion;
adding natural sand, broken stone, regenerated fine aggregate and regenerated coarse aggregate into the modified hydrotalcite emulsion, stirring and mixing uniformly, heating to 50 ℃, keeping the temperature and reacting for 1h, taking out, and air-drying to obtain modified aggregate;
p2, weighing 39kg of portland cement, 11kg of water and 3kg of HSB aliphatic superplasticizer; adding portland cement, an HSB aliphatic superplasticizer and the rest 3.6kg of dihydroxy terminated polysiloxane modified hydrotalcite into the modified aggregate, stirring and blending for 5min at the rotating speed of 600rpm, adding water after stirring, stirring and blending for 1min at the rotating speed of 1500rpm to obtain the anti-permeability recycled concrete.
Examples 2 to 9, differing from example 1 only in that: the sources of the bishydroxy-terminated polysiloxane-modified hydrotalcite are different, and the specific sources are shown in table 3.
TABLE 3 sources of bishydroxy terminated polysiloxane modified hydrotalcite from examples 1-9
| Examples | Preparation example | Examples | Preparation example |
| Example 2 | Preparation example 2 | Example 6 | Preparation example 6 |
| Example 3 | Preparation example 3 | Example 7 | Preparation example 7 |
| Example 4 | Preparation example 4 | Example 8 | Preparation example 8 |
| Example 5 | Preparation example 5 | Example 9 | Preparation example 9 |
Examples 10 to 16
An impervious recycled concrete which differs from example 9 only in that: the raw material quality of the impervious recycled concrete is different, and the specific source is shown in table 4.
TABLE 4 quality of raw materials in impervious recycled concrete of examples 10-11
Example 17
An impervious recycled concrete which differs from example 16 only in that: the polycarboxylate water reducing agent and the like are used for replacing the HSB aliphatic high-efficiency water reducing agent.
Example 18
The impervious recycled concrete is different from the impervious recycled concrete in example 16 in that the modified hydrotalcite emulsion in the step P1 is heated to 60 ℃ and is subjected to heat preservation reaction for 2 hours.
Comparative example
Comparative example 1
An impervious recycled concrete is prepared by the following steps:
39kg of portland cement, 11kg of water and 3kg of an HSB aliphatic superplasticizer, 6kg of the bishydroxy-terminated polysiloxane-modified hydrotalcite prepared in preparation example 1, 13.6kg of natural sand, 23.2kg of crushed stone, 54.4kg of recycled fine aggregate and 92.8kg of recycled coarse aggregate were weighed;
putting portland cement, an HSB aliphatic superplasticizer, dihydroxy terminated polysiloxane modified hydrotalcite, natural sand, broken stone, regenerated fine aggregate and regenerated coarse aggregate into a stirrer, stirring and blending for 5min at the rotating speed of 600rpm, adding water after stirring, stirring and blending for 1min at the rotating speed of 1500rpm to obtain the anti-seepage regenerated concrete.
Comparative example 2
An impervious recycled concrete is different from the concrete in example 1 in that hydrotalcite and the like are used for replacing dihydroxy terminated polysiloxane modified hydrotalcite by mass.
Performance test
Preparation of test pieces: the concrete test molds of 100mm × 100mm × 100mm in size were poured into the concrete test molds of examples 1 to 18 and comparative examples 1 to 2, respectively, and the concrete in the test molds was cured for 28 days under standard curing conditions after molding to obtain test pieces.
Compressive strength: detecting the compressive strength of the cured test piece according to GB/T50081-2010 standard of test methods for mechanical properties of common concrete;
and (3) detecting the impermeability:
detecting the water seepage depth according to a water seepage height method in GB/T50082-2009 in examples 1-14 and comparative examples 1-3, wherein a reagent used for detection is seawater;
the penetration depth of the chloride ions is detected according to a rapid chloride ion migration coefficient method in GB/T50082-2009 in examples 1-14 and comparative examples 1-3, and the detection reagent is seawater;
the weight loss rate after sulfate ion corrosion is measured according to a sulfate corrosion resistance test in GB/T50082-2009, dry-wet cycle test equipment is weighed after performing a dry-wet cycle test for 150 times, and a reagent used for detection is seawater.
TABLE 5 test results of 28d compressive Strength of examples 1-18 and comparative examples 1-2
TABLE 6 results of depth test of impermeability in examples 1-18 and comparative examples 1-2
By combining example 1 and comparative examples 1-2, and by combining the data in tables 5-6, it can be seen that in comparative example 1, the compressive strength of the aggregate is slightly reduced when the aggregate is modified without using the dihydroxy-terminated polysiloxane modified hydrotalcite, but the water penetration depth, the chloride ion penetration depth and the weight loss rate are all higher than those of example 1, which proves that the compressive strength and the impermeability of the recycled concrete can be improved when the dihydroxy-terminated polysiloxane modified hydrotalcite is used for treating the aggregate in advance;
in comparative example 2, the compressive strength of the hydrotalcite which is not modified by the dihydroxy terminated polysiloxane is slightly lower than that of example 1, and the water penetration depth is higher than that of example 1, so that the dihydroxy terminated polysiloxane can effectively improve the compressive strength and the water penetration resistance of the recycled concrete after the hydrotalcite is modified.
Combining examples 1-3 and the data in Table 6, it can be seen that the ratio of hydrotalcite to dihydroxy terminated polysiloxane in examples 1-3 is different, and the grafting ratio of dihydroxy terminated polysiloxane on the surface of example 2 is higher than that of example 3, but the penetration depth of chloride ions and the weight loss ratio are higher than those of example 3, which proves that the grafting ratio of dihydroxy terminated polysiloxane is too high to cause the adsorption and fixation efficiency of hydrotalcite to anions to be reduced.
It can be seen from the data of examples 9-13 and tables 5-6 that the water cement ratio has a large influence on the properties of the recycled concrete, and the compressive strength and the impermeability of the recycled concrete prepared by the method are best when the water cement ratio is controlled to be 0.25.
By combining examples 16 and 18 and the data in table 6, it can be seen that the compounding of the polycarboxylate water reducing agent and the bishydroxy terminated polysiloxane modified hydrotalcite can further improve the compressive strength and the impermeability of the recycled concrete.
The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.
Claims (9)
1. The anti-permeability recycled concrete is characterized by being prepared from the following raw materials in parts by weight:
390-410 parts of Portland cement
680-720 parts of fine aggregate
1160-1200 parts of coarse aggregate
110-144 parts of water
30-51 parts of water reducing agent
60-100 parts of dihydroxy terminated polysiloxane modified hydrotalcite;
the content of the recycled fine aggregate in the fine aggregate and the content of the recycled coarse aggregate in the coarse aggregate are both 20 to 80 weight percent.
2. The impervious recycled concrete of claim 1, wherein: the preparation method of the dihydroxy terminated polysiloxane modified hydrotalcite comprises the following steps:
adjusting the pH value of deionized water to 8-10, adding hydrotalcite into the deionized water, wherein the weight ratio of the hydrotalcite to water is 1 (3-5), and preparing a hydrotalcite emulsion;
adding dihydroxy terminated polysiloxane into the hydrotalcite emulsion, wherein the weight ratio of the dihydroxy terminated polysiloxane to the hydrotalcite is 1 (0.2-0.4), heating to 35-45 ℃, and carrying out heat preservation reaction for 0.5-1.5 h to obtain the dihydroxy terminated polysiloxane modified hydrotalcite.
3. The impervious recycled concrete of claim 2, wherein: the weight ratio of the dihydroxy terminated polysiloxane to the hydrotalcite is 1: 0.25.
4. The impervious recycled concrete of claim 3, wherein: the hydroxyl content of the dihydroxy-terminated polysiloxane is 7.5-8.5%.
5. The impervious recycled concrete of claim 2, wherein: the particle size of the hydrotalcite is 300-400 meshes.
6. The impervious recycled concrete of claim 1, wherein: the weight ratio of the cement to the water is 1: 0.3.
7. The impervious recycled concrete of claim 1, wherein: the water reducing agent is polycarboxylate water reducing agent.
8. The method of any one of claims 1-7, comprising the steps of:
p1 and aggregate treatment: weighing dihydroxy-terminated polysiloxane modified hydrotalcite, fine aggregate and coarse aggregate according to the formula ratio, putting 40-60 wt% of dihydroxy-terminated polysiloxane modified hydrotalcite into deionized water to prepare modified hydrotalcite emulsion, putting the coarse aggregate and the fine aggregate into the modified hydrotalcite emulsion, stirring and mixing uniformly, heating to 50-60 ℃, carrying out heat preservation reaction for 1-2 h, and air-drying to obtain modified aggregate;
p2, preparation of recycled concrete: weighing Portland cement, water, a water reducing agent and an air entraining agent according to the formula ratio, adding the raw materials and the residual dihydroxy terminated polysiloxane modified hydrotalcite into modified aggregate, and stirring and blending to obtain the anti-permeability recycled concrete.
9. The method for preparing impervious recycled concrete according to any one of claim 8, wherein 54 to 55wt% of dihydroxy terminated polysiloxane modified hydrotalcite is taken from step P1 and coarse aggregates and fine aggregates are treated.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110972029.6A CN113603421A (en) | 2021-08-23 | 2021-08-23 | Impervious recycled concrete and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110972029.6A CN113603421A (en) | 2021-08-23 | 2021-08-23 | Impervious recycled concrete and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113603421A true CN113603421A (en) | 2021-11-05 |
Family
ID=78341727
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110972029.6A Pending CN113603421A (en) | 2021-08-23 | 2021-08-23 | Impervious recycled concrete and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113603421A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115028400A (en) * | 2022-06-01 | 2022-09-09 | 杭州五友建材有限公司 | Recycled concrete and preparation method thereof |
| CN116003033A (en) * | 2023-02-01 | 2023-04-25 | 陕西国琳建设工程有限公司 | Recycled concrete and preparation method thereof |
| CN117263624A (en) * | 2023-11-22 | 2023-12-22 | 长沙中科盛联新材料有限公司 | Recycled aggregate concrete and preparation method thereof |
| CN116003033B (en) * | 2023-02-01 | 2024-07-02 | 陕西国琳建设工程有限公司 | Recycled concrete and preparation method thereof |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5399329A (en) * | 1993-07-06 | 1995-03-21 | Aristech Chemical Corporation | Hydrotalcite-like materials having a sheet-like morphology and process for production thereof |
| CN110054442A (en) * | 2019-04-26 | 2019-07-26 | 四川衡鼎建材有限公司 | A kind of regeneration concrete mixture and its preparation process |
| CN110255963A (en) * | 2019-06-14 | 2019-09-20 | 河海大学 | A kind of preparation method of modified houghite sulfate corrosion-resistance preservative for concrete |
| CN112778874A (en) * | 2020-12-31 | 2021-05-11 | 桂林理工大学 | Ocean engineering concrete corrosion-resistant coating and preparation method thereof |
-
2021
- 2021-08-23 CN CN202110972029.6A patent/CN113603421A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5399329A (en) * | 1993-07-06 | 1995-03-21 | Aristech Chemical Corporation | Hydrotalcite-like materials having a sheet-like morphology and process for production thereof |
| CN110054442A (en) * | 2019-04-26 | 2019-07-26 | 四川衡鼎建材有限公司 | A kind of regeneration concrete mixture and its preparation process |
| CN110255963A (en) * | 2019-06-14 | 2019-09-20 | 河海大学 | A kind of preparation method of modified houghite sulfate corrosion-resistance preservative for concrete |
| CN112778874A (en) * | 2020-12-31 | 2021-05-11 | 桂林理工大学 | Ocean engineering concrete corrosion-resistant coating and preparation method thereof |
Non-Patent Citations (2)
| Title |
|---|
| 姜新佩等: "富含砖粒再生混凝土的抗渗性试验", 《兰州理工大学学报》 * |
| 李青山等: "《微型高分子化学实验》", 31 July 2003, 化学工业出版社 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115028400A (en) * | 2022-06-01 | 2022-09-09 | 杭州五友建材有限公司 | Recycled concrete and preparation method thereof |
| CN116003033A (en) * | 2023-02-01 | 2023-04-25 | 陕西国琳建设工程有限公司 | Recycled concrete and preparation method thereof |
| CN116003033B (en) * | 2023-02-01 | 2024-07-02 | 陕西国琳建设工程有限公司 | Recycled concrete and preparation method thereof |
| CN117263624A (en) * | 2023-11-22 | 2023-12-22 | 长沙中科盛联新材料有限公司 | Recycled aggregate concrete and preparation method thereof |
| CN117263624B (en) * | 2023-11-22 | 2024-02-06 | 长沙中科盛联新材料有限公司 | Recycled aggregate concrete and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4473345B2 (en) | Cement formulation | |
| CN110218051A (en) | A kind of high strength lightweight aggregate concrete and its preparation process | |
| CN111439942B (en) | Method for preparing cement admixture by utilizing engineering waste soil, cement admixture and cement composition | |
| CN113603421A (en) | Impervious recycled concrete and preparation method thereof | |
| Nazari et al. | The effects of ZnO2 nanoparticles on strength assessments and water permeability of concrete in different curing media | |
| Khan et al. | Effect of Microsilica on Strength and Microstructure of the GGBS-based Cement composites | |
| CN112110705B (en) | Self-repairing semi-rigid base material for recycling construction waste | |
| JP2010524823A (en) | Light weight additive, its production method and use | |
| Nejad et al. | Effects of calcium carbonate nanoparticles and fly ash on mechanical and permeability properties of concrete | |
| Ayodele et al. | Effect of sawdust ash and eggshell ash on selected engineering properties of lateralized bricks for low cost housing | |
| CN109020405B (en) | High-performance concrete with excellent impermeability and preparation method thereof | |
| Song et al. | Compressive strength, water and chloride transport properties of early CO2-cured Portland cement-fly ash-slag ternary mortars | |
| CN111807779B (en) | High-strength waterproof soil consolidation agent | |
| Rashidian-Dezfouli et al. | Role of ground glass fiber as a pozzolan in Portland cement concrete | |
| WO2021179067A1 (en) | Use of amorphous silica reagent produced from serpentine in concrete preparation | |
| CN116354679A (en) | Strain hardening type recycled coarse aggregate concrete and preparation method thereof | |
| Idrees et al. | Effectiveness of metakaolin and hybrid polymers incorporated mortar for the compressive strength and acid resistance of industrial and wastewater infrastructure | |
| CN114394798A (en) | Environment-friendly solid waste recycled concrete and preparation process thereof | |
| Asiwaju-Bello et al. | Effect of salt water on the compressive strength of ceramic powder concrete | |
| CN115745447B (en) | Concrete prepared by regenerating waste concrete and preparation method thereof | |
| Ahmad et al. | Experimental study of cold–Bonded artificial lightweight aggregate concrete | |
| Amin et al. | Transport properties of concrete containing lithium slag | |
| CN115043640A (en) | Outdoor floor ceramic wood material and using method thereof | |
| El-Mahllawy et al. | The influence of aggregate type on the physico-mechanical properties of magnesia cement pastes | |
| Olivia et al. | Improvements in the strength and water penetrability of low calcium fly ash based geopolymer concrete |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20211105 |