CN103472213B - Method for measuring strength of cementing materials - Google Patents

Abstract

The invention discloses a method for measuring the strength of cementing materials. The method includes the following steps: step1, testing the apparent density of cement and the apparent density of a mineral admixture, step2, obtaining the reaction degree of the mineral admixture in slurry of the cementing materials, step3, obtaining the hydration degree of the cement in the slurry of the cementing materials, step4, obtaining three main influence factors influencing the strength of the cementing materials, step5, establishing a cementing material strength GM (1,4) model, and step6, substituting the three main influence factors of the cementing materials to be measured to the cementing material strength GM (1,4) model to obtain the strength of the cementing materials. According to the method, the strength of different cementing material combinations can be obtained by calculation through simple tests, and the method is high in accuracy, good in reliability and capable of solving the problem that only through strength tests can the strengths of all the different cementing material combinations be obtained.

Description

A kind of measuring method of Binder Materials intensity

Technical field

The present invention relates to a kind of measuring method, particularly the measuring method of Binder Materials intensity.

Background technology

Strength of cement carries out testing obtaining according to " Test method for strength of hydraulic cement mortar (ISO method) " (GB/T17671-1999), and prepare high performance concrete at present and generally all want Adding Mineral Admixtures, Binder Materials is formed and becomes various and complicated, and the intensity of different Binder Materials combination generally all just can will be obtained by strength test, so not only require shaping a large amount of glue sand test specimen, also to wait until the curing age 28d of glue sand test specimen simultaneously, not only loaded down with trivial details but also consuming time, cause the consume of a large amount of manpower and materials.

Up to now, investigation and application for Binder Materials intensity is more, and comparatively wide and design accuracy the is higher method of application mainly contains the improvement modification method etc. of neural net method, Simplex-barycenter design method, orthogonal design method and experimental formula homing method and these methods.Neural net method wherein predicts the outcome to obtain accurate design, needs the trial value of abundant training network, can not obtain the analytical expression between intensity and influence factor in addition; Orthogonal design method and experimental formula homing method consider that the factor affecting intensity is limited, equally owing to not having the analytical expression between corresponding intensity and influence factor, cannot draw the association size of each influence factor to intensity; There is certain restrictive condition in the use of Simplex-barycenter design method, if the volume of mineral admixture is no more than a definite limitation, its universality needs to be verified further.

Summary of the invention

Technical matters: the measuring method that the invention provides a kind of Binder Materials intensity.It not only accuracy and reliability high, and only need by simply test just can calculate different Binder Materials combined strength, avoiding different Binder Materials combined strength all needs just can obtain through 28d strength test.

Technical scheme: the measuring method of Binder Materials intensity of the present invention, comprises the following steps:

1) apparent density of cement and the apparent density of mineral admixture is tested;

2) extent of reaction α of mineral admixture in the saturated limewater containing NaOH is obtained by Selective dissolution method test _{mA, SL, i}, wherein i represents mineral admixture kind, and the pH value of described saturated limewater is 13 ~ 14; Then the extent of reaction α of mineral admixture in two groups of Binder Materials slurries is obtained by Selective dissolution method test _{mA, i}, draw the extent of reaction test regression constant of mineral admixture in Binder Materials slurry, A ₁for exponential function advance constant, A ₂for built-in constant, finally calculate the extent of reaction of mineral admixture in Binder Materials slurry;

3) by the degree of hydration of chemical combined water test cement under Different Water-Cement Ratio, the degree of hydration test regression constant of cement in Binder Materials slurry is obtained, B ₁for exponential function advance constant, B ₂for built-in constant, then calculate the degree of hydration of cement in Binder Materials slurry;

4) three major influence factors of Binder Materials intensity are obtained: 1. by calculating water-cement ratio W/B; 2. Binder Materials bulk density ρ is obtained by test _bD; 3. by calculating the volume ratio of hydrated product calcium silicate and unhydrated cement and mineral admixture;

5) with three major influence factors for correlative factor sequence, Binder Materials intensity is system features data sequence, adopt About Modelling of Grey systems set up Binder Materials intensity GM (Isosorbide-5-Nitrae) model.

6) three major influence factors need measuring Binder Materials are substituted in Binder Materials intensity GM (Isosorbide-5-Nitrae) models can obtain Binder Materials intensity results.

The step 2 of the inventive method) in, adopt following formula to calculate the extent of reaction of mineral admixture in Binder Materials slurry:

${\mathrm{\α}}_{\mathrm{MA},i}={\mathrm{\α}}_{\mathrm{MA},\mathrm{SL},i}+A_1{e}^{\frac{A_2\·w}{c+\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{m}_{\mathrm{MA},i}\·{\mathrm{\α}}_{\mathrm{MA},\mathrm{SL},i}}}$

In formula:

α _{mA, i}: the extent of reaction of mineral admixture in Binder Materials slurry;

α _{mA, SL, i}: the extent of reaction of mineral admixture in the saturated limewater containing NaOH;

M _{mA, i}: the consumption of Binder Materials slurry Minerals admixture;

C: the consumption of cement in Binder Materials slurry;

W: water consumption; N is mineral admixture kind sum;

E: natural constant, its value is 2.718;

A ₁, A ₂: the extent of reaction test regression constant of mineral admixture in Binder Materials slurry, is respectively exponential function advance constant and built-in constant.

In the step 3) of the inventive method, following formula is adopted to calculate the degree of hydration of cement in Binder Materials slurry:

${\mathrm{\α}}_C=B_1{e}^{-\frac{B_2}{w/(c+{\mathrm{\α}}_{\mathrm{MA},i}{\·m}_{\mathrm{MA},i})}}$

In formula:

α _c: the degree of hydration of cement in Binder Materials slurry;

B ₁, B ₂: the degree of hydration test regression constant of cement in Binder Materials slurry, is respectively exponential function advance constant and built-in constant.

In the step 4) of the inventive method, calculate the volume ratio of hydrated product calcium silicate and unhydrated cement and mineral admixture according to following formula:

$\mathrm{VR}=\frac{171\·(n_{C2S}+n_{C3S})\·{\mathrm{\α}}_C\·c+3.197\·\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{f}_{S,\mathrm{MA},i}{\·m}_{\mathrm{MA},i}\·{\mathrm{\α}}_{\mathrm{MA},i}}{2.604\·[\frac{c\·(1-{\mathrm{\α}}_C)}{{\mathrm{\ρ}}_C}+\underset{i=1}{\overset{n}{\mathrm{\Σ}}}\frac{m_{\mathrm{MA},i}\·(1-{\mathrm{\α}}_{\mathrm{MA},i})}{{\mathrm{\ρ}}_{\mathrm{MA},i}}]}$

In formula, VR: the volume ratio of calcium silicate and unhydrated cement and mineral admixture;

F _{s, MA, i}: the massfraction of monox in mineral admixture chemical composition;

N _c2Sand n _c3S: be respectively cement composition mesosilicic acid dicalcium and tricalcium silicate molal quantity;

ρ _cand ρ _{mA, i}: the apparent density being respectively cement and mineral admixture.

Beneficial effect: the present invention compared with prior art, has the following advantages:

1. existing Binder Materials intensity is all generally carry out glue sand test by specification to obtain, and experiment work amount is large, needs at substantial Binder Materials simultaneously, and the present invention only needs a small amount of Binder Materials to carry out simple test can obtain corresponding Binder Materials intensity.

2. existing Binder Materials strength model or the major influence factors of intensity cannot be embodied in a model, or can not get corresponding analytical expression, or applicable elements comparatively harshness limit its usable range.The present invention obtains Binder Materials intensity analytical expression by three major influence factors, applied widely.

3. existing Binder Materials strength model or accuracy lower, reliability is poor, for ensureing that its precision needs abundant test findings modeling, the present invention uses the About Modelling of Grey systems that needed for modeling, test findings sample is less, the Binder Materials intensity obtained is compared with test actual strength, and its average relative error is within 10%, and whole result relative error is within 15%, accuracy is higher, and reliability is better.

Accompanying drawing explanation

Fig. 1 is the 28d strength simulation value that obtains of Binder Materials intensity GM (Isosorbide-5-Nitrae) Residual Error Modified Model and trial value comparison diagram.

Fig. 2 is the relative error figure of the 28d strength simulation value that obtains of Binder Materials intensity GM (Isosorbide-5-Nitrae) Residual Error Modified Model and trial value.

Embodiment

Gelling gel material symbol is respectively: CI is the PI52.5 class g cement that little Ye Tian cement mill, the south of the River produces; CII is the PII42.5 class g cement that Huaxin Concrete Co., Ltd produces; FAI-1, FAI-2 and FAI-3 are respectively the I level flyash of Different sources; FAII-1 and FAII-2 is respectively the II level flyash of Different sources; BFS95-1 and BFS95-2 is respectively the S95 level breeze of Different sources; S75 and S105 is respectively S75 and S105 level breeze; It is 550m that MK-1 and MK-2 is respectively specific surface area ²/ kg and 1200m ²the metakaolin of/kg; LP, QP and EP are respectively agstone, quartz sand powder and the emery dust that purity is greater than 90%.

1) the cement apparent density obtained and mineral admixture apparent density is tested, as shown in table 1.

Table 1 cement and mineral admixture apparent density/g/cm ³

1) mineral admixture is obtained containing the extent of reaction in the saturated limewater of NaOH by Selective dissolution method test, as shown in table 2; Obtain the extent of reaction of mineral admixture in two groups of Binder Materials slurries by Selective dissolution method test, draw the extent of reaction test regression constant of mineral admixture in Binder Materials slurry, A ₁for exponential function advance constant, A ₂for built-in constant, as shown in table 3, the extent of reaction computing formula of different minerals admixture in Binder Materials slurry can be obtained accordingly.

The 28d extent of reaction of table 2 mineral admixture in the saturated limewater containing NaOH

Table 3 mineral admixture is extent of reaction test regression constant in Binder Materials slurry

3) by the degree of hydration of chemical combined water test cement under Different Water-Cement Ratio, the degree of hydration test regression constant of cement in Binder Materials slurry is obtained, B ₁for exponential function advance constant, B ₂for built-in constant, as shown in table 4, the degree of hydration computing formula of cement in Binder Materials slurry can be obtained accordingly.

Table 4 cement is degree of hydration test regression constant in Binder Materials slurry

4) three major influence factors of Binder Materials intensity are obtained: 1. by calculating water-cement ratio W/B; 2. Binder Materials bulk density ρ is obtained by test _bD; 3. by calculating the volume ratio of hydrated product calcium silicate and unhydrated cement and mineral admixture, as shown in table 5.

Table 5 Binder Materials intensity with three major influence factors

In table 5, letter in test number represents Binder Materials composition, numeral before Binder Materials letter then represents its volume, illustrate for (M:7CI+FAI-1+2BFS95-1), M represents glue sand, CI, FAI-1 and BFS95-1 represents that in this group glue sand, Binder Materials forms cement used respectively, flyash and breeze, and CI, numeral before each letter of FAI-1 and BFS95-1 (usually omit by numeral 1, as the numeral 1 before FAI-1 is not indicated) then represent starting material volume separately, be respectively 70%CI, 10%FAI-1 and 20%BFS95-1, and reference water earth rubber sand test sample number into spectrum is respectively (M:CI) and (M:CII).CS represents Binder Materials 28d intensity, MPa.

5) with three major influence factors for correlative factor sequence, Binder Materials intensity is system features data sequence, About Modelling of Grey systems is adopted to set up Binder Materials intensity GM (1,4) model, wherein GM (1,4) represent that exponent number is 1, variable is the gray model of 4, " 1 " represents order of equation number in gray model, and " 4 " represent the number of variable in gray model equation.

When be taken as time, the time proximity response type of Binder Materials intensity GM (Isosorbide-5-Nitrae) model obtained is:

$\begin{array}{c}{{\widehat{\mathrm{CS}}}_1}^{\left(1\right)}(k+1)=\{65.33-1.812[16.576W/{B_2}^{\left(1\right)}(k+1)+24.466{{\mathrm{\ρ}}_{\mathrm{BD}3}}^{\left(1\right)}(k+1)+5.22{{\mathrm{VR}}_4}^{\left(1\right)}(k+1)\left]\right\}{e}^{-0.552k}\\ +1.812[16.576W/{B_2}^{\left(1\right)}(k+1)+24.466{{\mathrm{\ρ}}_{\mathrm{BD}3}}^{\left(1\right)}(k+1)+5.22{{\mathrm{VR}}_4}^{\left(1\right)}(k+1)\end{array}$

In formula, : intensity CS ₁ ⁽⁰⁾(k+1) analogue value of 1-AGO sequence;

W/B ₂ ⁽¹⁾(k+1), ρ _bD3 ⁽¹⁾and VR (k+1) ₄ ⁽¹⁾(k+1): be respectively water-cement ratio W/B ₂ ⁽⁰⁾(k+1), Binder Materials bulk density ρ _bD3 ⁽⁰⁾and the volume ratio VR of hydrated product calcium silicate and unhydrated cement and mineral admixture (k+1) ₄ ⁽⁰⁾(k+1) 1-AGO sequence;

K-test specimen sequence number.

The regressive reduction-type of Binder Materials intensity GM (Isosorbide-5-Nitrae) model can be obtained accordingly:

${{\widehat{\mathrm{CS}}}_1}^{\left(0\right)}(k+1)={{\widehat{\mathrm{CS}}}_1}^{\left(1\right)}(k+1)-{{\widehat{\mathrm{CS}}}_1}^{\left(1\right)}\left(k\right)$

In formula, intensity CS ₁ ⁽⁰⁾(k+1) the analogue value.

For improving accuracy and the reliability of Binder Materials intensity GM (Isosorbide-5-Nitrae) model, intensity restoring data residual sequence can be adopted to set up Residual GM (1,1) model Binder Materials intensity GM (Isosorbide-5-Nitrae) model is revised.

When k >=4, the programme regressive reduction-type of Residual GM (1, the 1) model obtained of MATLAB is adopted to be:

${\widehat{\mathrm{CS}}}^{\left(0\right)}(k+1)=-13.451e^{-0.04k}$

In formula, the intensity residual GM analogue value.

Therefore, when k >=4, Binder Materials intensity GM (Isosorbide-5-Nitrae) Residual Error Modified Model is:

$\begin{array}{c}{{\widehat{\mathrm{CS}}}_1}^{\left(1\right)}(k+1)=\{65.33-1.812[16.576W/{B_2}^{\left(1\right)}(k+1)+24.466{{\mathrm{\ρ}}_{\mathrm{BD}3}}^{\left(1\right)}(k+1)+5.22{{\mathrm{VR}}_4}^{\left(1\right)}(k+1)\left]\right\}{e}^{-0.552k}\\ +1.812[16.576W/{B_2}^{\left(1\right)}(k+1)+24.466{{\mathrm{\ρ}}_{\mathrm{BD}3}}^{\left(1\right)}(k+1)+5.22{{\mathrm{VR}}_4}^{\left(1\right)}(k+1)\end{array}$

${{\widehat{\mathrm{CS}}}_1}^{\left(0\right)}(k+1)={{\widehat{\mathrm{CS}}}_1}^{\left(1\right)}(k+1)-{{\widehat{\mathrm{CS}}}_1}^{\left(1\right)}\left(k\right)+{\widehat{\mathrm{CS}}}^{\left(0\right)}(k+1)$

As shown in Figure 1, relative error as shown in Figure 2 for the 28d strength simulation value adopting Binder Materials intensity GM (Isosorbide-5-Nitrae) Residual Error Modified Model to obtain and trial value contrast.As can be seen here, the method accuracy is higher, and reliability is better.

6) choose arbitrarily needing can obtain Binder Materials intensity results in Binder Materials three major influence factors substitution Binder Materials intensity GM (Isosorbide-5-Nitrae) Residual Error Modified Models of measured intensity, as shown in table 6.

The Binder Materials strength test value that table 6 need be measured and the Comparative result that this method obtains

This shows, this method accuracy is high, good reliability, achieves and can obtain different Binder Materials 28d intensity results by simple experiment.

Claims (4)

1. a measuring method for Binder Materials intensity, is characterized in that, the method comprises the following steps:

1) apparent density of cement and the apparent density of mineral admixture is tested;

2) extent of reaction α of mineral admixture in the saturated limewater containing NaOH is obtained by Selective dissolution method test _{mA, SL, i}, wherein i represents mineral admixture kind, and the pH value of described saturated limewater is 13 ~ 14; Then the extent of reaction α of mineral admixture in two groups of Binder Materials slurries is obtained by Selective dissolution method test _{mA, i}, draw the extent of reaction test regression constant of mineral admixture in Binder Materials slurry, A ₁for exponential function advance constant, A ₂for built-in constant, finally calculate the extent of reaction of mineral admixture in Binder Materials slurry;

3) by the degree of hydration of chemical combined water test cement under Different Water-Cement Ratio, the degree of hydration test regression constant of cement in Binder Materials slurry is obtained, B ₁for exponential function advance constant, B ₂for built-in constant, then calculate the degree of hydration of cement in Binder Materials slurry;

4) three major influence factors of Binder Materials intensity are obtained: 1. by calculating water-cement ratio W/B; 2. Binder Materials bulk density ρ is obtained by test _bD; 3. by calculating the volume ratio of hydrated product calcium silicate and unhydrated cement and mineral admixture;

5) with three major influence factors for correlative factor sequence, Binder Materials intensity is system features data sequence, adopt About Modelling of Grey systems set up Binder Materials intensity GM (Isosorbide-5-Nitrae) model;

6) three major influence factors need measuring Binder Materials are substituted in Binder Materials intensity GM (Isosorbide-5-Nitrae) models can obtain Binder Materials intensity results.

2. the measuring method of a kind of Binder Materials intensity according to claim 1, is characterized in that, described step 2) in adopt following formula calculate the extent of reaction of mineral admixture in Binder Materials slurry:

${\mathrm{\α}}_{\mathrm{MA},i}={\mathrm{\α}}_{\mathrm{MA},\mathrm{SL},i}+A_1{e}^{\frac{A_2\·w}{c+\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{m}_{\mathrm{MA},i}\·{\mathrm{\α}}_{\mathrm{MA},\mathrm{SL},i}}}$

In formula:

α _{mA, i}: the extent of reaction of mineral admixture in Binder Materials slurry;

α _{mA, SL, i}: the extent of reaction of mineral admixture in the saturated limewater containing NaOH;

M _{mA, i}: the consumption of Binder Materials slurry Minerals admixture;

C: the consumption of cement in Binder Materials slurry;

W: water consumption; N is mineral admixture kind sum;

E: natural constant, its value is 2.718;

A ₁, A ₂: the extent of reaction test regression constant of mineral admixture in Binder Materials slurry, is respectively exponential function advance constant and built-in constant.

3. the measuring method of a kind of Binder Materials intensity according to claim 1, is characterized in that, described step 3) in adopt following formula calculate the degree of hydration of cement in Binder Materials slurry:

${\mathrm{\α}}_C=B_1{e}^{-\frac{B_2}{w/(c+{\mathrm{\α}}_{\mathrm{MA},i}\·m_{\mathrm{MA},i})}}$

In formula:

α _c: the degree of hydration of cement in Binder Materials slurry;

B ₁, B ₂: the degree of hydration test regression constant of cement in Binder Materials slurry, is respectively exponential function advance constant and built-in constant.

4. the measuring method of a kind of Binder Materials intensity according to claim 1,2 or 3, is characterized in that, described step 4) in calculate the volume ratio of hydrated product calcium silicate and unhydrated cement and mineral admixture according to following formula:

$\mathrm{VR}=\frac{171\·(n_{C2S}+n_{C3S})\·{\mathrm{\α}}_C\·c+3.197\·\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{f}_{S,\mathrm{MA},i}\·m_{\mathrm{MA},i}\·{\mathrm{\α}}_{\mathrm{MA},i}}{2.604[\frac{c\·(1-{\mathrm{\α}}_C)}{{\mathrm{\ρ}}_C}+\underset{i=1}{\overset{n}{\mathrm{\Σ}}}\frac{m_{\mathrm{MA},i}\·(1-{\mathrm{\α}}_{\mathrm{MA},i})}{{\mathrm{\ρ}}_{\mathrm{MA},i}}]}$

In formula, VR: the volume ratio of calcium silicate and unhydrated cement and mineral admixture;

F _{s, MA, i}: the massfraction of monox in mineral admixture chemical composition;

N _c2Sand n _c3S: be respectively cement composition mesosilicic acid dicalcium and tricalcium silicate molal quantity;

ρ _cand ρ _{mA, i}: the apparent density being respectively cement and mineral admixture.