CN101008600A - Quick determination method of water content of block - Google Patents

Abstract

This invention discloses one non-clay block establishing with water rapid test method, which comprises the following steps: firstly taking sample in the needed test agent; then grinding the test sample powder into set scale and weighting proper weight test sample m0 in sealing environment mixture with calcium acetylene; computing out test sample water rate according to the pressure value and mixture test sample.

Description

A kind of rapid assay methods of water content of block

Technical field

The present invention relates to a kind of rapid assay methods technical field of non-clay class water content of block.

Background technology

The blockwork cracking is one of major reason that influences the urban architecture quality, and the water percentage of walling unit is the key factor that influences the building block building cracking.The equipment and instrument how exploitation, application measure the walling unit water percentage fast and accurately is the key that improves the walling unit quality.The rapid assay methods of formulating rational water content of block not only improves construction quality, and can remedy domestic blank.Though developed the ripe system of many material measurement of water-content coefficient abroad, adapt to the actual conditions of Chinese architecture industry, still be necessary to investigate in a large number and experimental work.

Develop some water percentage detection methods both at home and abroad, mainly comprised oven drying method, hydrometer method, alcohol firing method, microwave oven process, electric-resistivity method, capacitance method, near infrared light tester method, microwave moisture meter method and nucleon density instrument method etc.But a lot of methods are too complicated in the mensuration process, require the very long testing period, can't solve building-site requirement quick, that accurately measure.When defect occurring and occur, can not satisfy the requirement of clear and definite confirmation of responsibility.Therefore, the rapid assay methods of the novel water content of block of research and development has important and practical meanings to detection, the supervision of construction quality.

Summary of the invention

Purpose of the present invention is exactly the problems referred to above that solve prior art, and a kind of method of fast measuring water content of block is provided, simple fast, the enforcement easily of this method.

The method principle that the present invention proposes is to utilize carbide of calcium and the rapid generated reactive gas of water, the characteristic that makes the increase of unit volume internal gas pressure, be to react specifically according to free water in carbide of calcium powder and the sample from building block, got, produce acetylene gas, air pressure in the unit volume internal gas pressure bottle is raise, according to the quality of the sample of weighing and the water percentage that the air pressure changing value calculates sample.

Its reaction equation is: CaC ₂+ 2H ₂O → Ca (OH) ₂+ C ₂H ₂↑

This method can be tested the free water that is present in grain surface and crystal grain gap, but can not test tie water or water of crystallization in the material.Therefore, this method can effectively be measured the free water of material internal.

According to this principle, the concrete technical scheme that the present invention takes is as follows:

A kind of rapid assay methods of water content of block, this method is: at first at the position sample of required test, then with the sample grinding to stipulating fineness, the sample of weighing approrpiate wts mixes with carbide of calcium in sealed environment, calculates the water percentage of sample according to the weight of force value that increases and recombined sample.

When calculating the water percentage of sample, the easiest, method is to utilize following formula fast: $h=\frac{m}{m_0}=\frac{36V\·\mathrm{\ΔP}}{m_0\mathrm{RT}}$ , h is the water percentage of sample in the formula, and unit is %, and m is the liquid water content in the specimen sample, m ₀Be the sample mass of weighing, R is a gas law constant, and T is an environment temperature, and the sealed environment container volume when V is sample and carbide of calcium hybrid reaction, Δ P are gaseous tension added value in the container.

Because according to reaction equation and equation for ideal gases, can calculate, be the container of V for the given volume capacity, its generation gas pressure change value is:

$\mathrm{\ΔP}=\frac{\mathrm{mRT}}{36V}---\left(1\right)$

Thereby the water percentage that can calculate sample is:

$h=\frac{m}{m_0}=\frac{36V\·\mathrm{\ΔP}}{m_0\mathrm{RT}}---\left(2\right)$

The rapid assay methods of above-mentioned water content of block during sampling, scrapes off the building block top layer with chisel, removal sticks to the foreign matter of block surfaces, and is at the position sample of required test, in abrasive disk that sample is thin together with fine aggregate grinding in the lump, until passing through sample sifter, the sample that weighing is got.The grain warp that generally requires sample is less than 0.25 mm, and easy like this and carbide of calcium mixes and reacts completely.

In order to make powdered sample and carbide of calcium fully mix, react, the particle diameter of carbide of calcium is preferably in 0.16～1.25mm, powdered sample and carbide of calcium incorporation time at least 5 minutes, powdered sample and carbide of calcium are mixed fully like this, and moisture and carbide of calcium in the sample can react completely.9-10g carbide of calcium powder is used in each test, and the purity of carbide of calcium should be greater than 98%.Generalized case allows be reflected to have in the manometric sealing air-pot and carries out, and leaves standstill and can obtain stable atmospheric pressure value in 5-10 minute.

Can calculate the water percentage of sample according to the quality of atmospheric pressure value and weighing.Water percentage for the same degree of depth of walling unit place, should be with the mean value of 3 measurement results as final water percentage, if the water cut value of single measurement and mean value differ more than 10%, then this measured value should be rejected, the mean value of getting 2 measured values of residue is as the water cut test result.

Beneficial effect of the present invention: compare with additive method, test process of the present invention is simple, and the test duration is short, test process control is easy, is particularly suitable for engineering site and detects.Method of the present invention is applicable to the building block of fast measuring non-clay class, as the water percentage of sand aerated-block, normal concrete small hollow block, FAS, concrete perforated brick etc., also can be used for the measurement of water-content coefficient of other building materialss.It also is suitable for the internal pair production of building block factory and detects not only applicable to building block engineering site fast measuring.

Embodiment

Specify the test process of the inventive method below with example:

Embodiment 1～3

To the building block of non-clay class, because of the water percentage at building block wall thickness, different depth place inequality.During sampling, scrape off the building block top layer, remove the foreign matter that sticks to block surfaces,, carry out water cut test at the position sample of required test with chisel.In abrasive disk that sample is thin together with fine aggregate grinding in the lump, until passing through the 0.25mm sample sifter.Water percentage according to eye estimate building block to be measured is about 10%, weighing sample m.10g。

In order to measure atmospheric pressure value accurately.The weighing quality of sample will be on the estimation water percentage and decide.The water cut of estimating is big more, and the quality of weighing just requires few more; The water percentage of estimating is more little, and the quality of weighing is then corresponding big more.

Is 640cm with hairbrush with volume V ³Air-pot clean up, air-pot is tilted to hold, slip in the bottle greater than 98% 10g carbide of calcium reagent at leisure along the air-pot wall purity of sealing; Then load weighted testing sample is poured in the bottle with the plastics scoop; Then rain glass is contained on the pressure vessel bottle, lid is tight.The air-pot of holding with a firm grip does not stop air-pot rotated and rocked at least 5 minutes, and powdered sample and carbide of calcium are mixed fully like this, and react.

Air-pot was left standstill 5-10 minute, obtain stable air pressure, getting the air pressure added value is 0.02MPa.According to formula $h=\frac{m}{m_0}=\frac{36V\·\mathrm{\ΔP}}{m_0\mathrm{RT}}$ The water percentage h that can calculate sample is 1.90%.M wherein.Be 10g, V is 640cm ³, Δ P is 0.02MPa, R is 8.3145Jmol ^-1K ^-1, T is 293k.

Test finishes, and the back is careful opens closing plug from an end, and acetylene and Air mixing gas slow release are gone out.Translate into pressure bottle then and pour out the material of the inside, clean with brush again.Since the residue of caustic lime and carbide of calcium etc. is arranged in the vial matter, thus must be careful when pouring out material, and no smoking and naked light.

Use the same method, sample is got the place of the same degree of depth of walling unit, records other twice water percentage and is respectively 1.84%, 1.98%.

Then the final water percentage of this walling unit is the mean value 1.91% that records for three times.

Water percentage for the same degree of depth of walling unit place, should be with the mean value of 3 measurement results as final water percentage, if the water cut value of single measurement and mean value differ more than 10%, then this measured value should be rejected, the mean value of getting 2 measured values of residue is as the water cut test result.

If formula that need not be above-mentioned calculates, also can calculate the water percentage of building block sample by other standard model comparison method.Amount and reaction front and back air pressure change value thereof to air pressure change value before and after standard model (water percentage the is known) reaction and building block to be measured compare, and can calculate the water percentage of testing sample equally.

For example, for a 20g standard model, its water percentage is 6%, and the air pressure increment of adopting the method to record is 0.12MPa.When weighing needs specimen 15g, record the air pressure increment and be 0.18MPa.Can obtain according to equation for ideal gases, the water percentage of specimen is 8%.

According to the air pressure change that records, calculate the water percentage of the building block of surveying, this is for one of ordinary skill in the art, and the utilization known systems can be derived and be drawn.

Claims (6)

1, a kind of rapid assay methods of water content of block, this method is: at first at the position sample of required test, then with the sample grinding to stipulating fineness, the sample of weighing approrpiate wts mixes with carbide of calcium in sealed environment, calculates the water percentage of sample according to the weight of force value that increases and recombined sample.

2, the rapid assay methods of water content of block as claimed in claim 1 is characterized in that: when calculating the water percentage of sample, utilize following formula: $h=\frac{m}{m_0}=\frac{36V\·\mathrm{\ΔP}}{m_0\mathrm{RT}}$ , h is the water percentage of sample in the formula, m is the liquid water content in the specimen sample, m ₀Be the sample mass of weighing, R is a gas law constant, and T is an environment temperature, and the sealed environment container volume when V is sample and carbide of calcium hybrid reaction, Δ P are gaseous tension added value in the container.

3, the rapid assay methods of water content of block as claimed in claim 1 is characterized in that: the grain of sample to be tested is through being equal to or less than 0.25mm.

4, the rapid assay methods of water content of block as claimed in claim 1 is characterized in that: the particle diameter of carbide of calcium is 0.16～1.25mm, and purity is greater than 98%.

5, the rapid assay methods of water content of block as claimed in claim 1 is characterized in that: 9-10g carbide of calcium powder is used in each test.

6, the rapid assay methods of water content of block as claimed in claim 1, it is characterized in that: for the water percentage at the same degree of depth of walling unit place, with the mean value of 3 measurement results as final water percentage, if the water cut value of single measurement and mean value differ more than 10%, then this measured value is rejected, the mean value of getting 2 measured values of residue is as the water cut test result.