A test method for evaluating slurry homogeneity

Abstract

The present invention discloses a test method for evaluating the homogeneity of slurry, comprising the following steps: pouring the prepared slurry into a cylindrical container, covering it with a plastic wrap and letting it stand, pouring out the slurry in the container after standing, weighing the weight of the remaining slurry in the container, and testing the particle size distribution of the upper and lower layers of the poured slurry, and then putting it into a mold for curing, cutting it into three parts after the curing is completed, testing their weight and compressive strength respectively, and obtaining a homogeneity index, and judging the homogeneity of the slurry by the homogeneity index. The test method for evaluating the homogeneity of slurry of the present invention is suitable for measuring the homogeneity of slurry. For high-flowability slurry composed of multiple gelling materials, the bleeding and stratification of the grouting material can be fundamentally eliminated by controlling the slurry homogeneity index.

Description

Technical Field

[0001] The invention relates to the technical field of slurry homogeneity determination methods, and in particular to a test method for evaluating slurry homogeneity. Background Art

[0002] Grouting material is a building material used for grouting construction of post-tensioned prestressed pipes. It is mainly composed of cement-based materials and functional admixtures, and its cementitious material system is becoming increasingly complex. Grouting material is generally composed of 4 to 6 different cementitious materials. Currently, commonly used cementitious materials mainly include cement, slag powder, fly ash, silica fume, limestone powder, expansion agent and chemical admixtures. Since the chemical composition and physical properties of each material are different, such as the apparent density, particle shape and particle size of each material are not the same, this type of slurry will inevitably produce uneven sedimentation and stratification, resulting in poor homogeneity of the slurry.

[0003] However, there is no testing method for slurry homogeneity in the current national and industry testing standards and various literatures, and the homogeneity of slurry cannot be judged by intuitive observation. Therefore, a test method for evaluating slurry homogeneity was invented. Summary of the invention

[0004] The purpose of the present invention is to provide a test method for evaluating slurry homogeneity, so as to fill the technical gap of the detection method for slurry homogeneity in the prior art.

[0005] To achieve the above purpose, an embodiment of the present invention provides a test method for evaluating the homogeneity of slurry, comprising the following steps: pouring the prepared slurry into a cylindrical container, covering it with a plastic wrap and letting it stand, pouring out the slurry in the container after standing, weighing the weight of the remaining slurry in the container, and testing the particle size distribution of the upper and lower layers of the poured slurry, and then putting it into a mold for curing, cutting it into three parts after the curing is completed, testing the weight and compressive strength of each part, and obtaining a homogeneity index, and judging the homogeneity of the slurry by the homogeneity index;

[0006] The test method for evaluating the homogeneity of the slurry specifically comprises the following steps:

[0007] a. Weigh the cementitious materials according to the combination ratio of the cementitious materials used in the slurry mix ratio, calculate the amount of water and admixtures used and weigh them according to the water-binder ratio and admixture dosage of the mix ratio;

[0008] b. Pour water into the grouting material stirring pot, start the grouting material stirring pot to stir slowly, mix the gelling material and water reducing agent evenly and add them into the stirring pot. After the addition is completed, adjust the stirring speed of the grouting material stirring pot and continue stirring;

[0009] c. Prepare two identical cylindrical containers A and B, weigh the weight M1 of container A, slowly and evenly pour the prepared slurry into container A, then immediately pour it into container B, let it stand and then pour it out;

[0010] d. Weigh the total mass of container A + the slurry attached to the container wall M2, and weigh the total mass of container B + the slurry attached to the container wall M3;

[0011] e. Calculate the mass of the remaining slurry in the container according to the following formula: m = (M3-M1)-(M2-M1) = M3-M2, and calculate the homogeneity coefficient α according to the following formula: α = m / (M2-M1);

[0012] f. Prepare a cylindrical container C that can be separated into upper and lower parts, pour the slurry into the container C, let it stand for a period of time, and then separate the upper and lower slurries to obtain an upper slurry 1 and a lower slurry 2;

[0013] g. Perform particle size analysis on the upper slurry 1 and the lower slurry 2 respectively to obtain the particle size analysis results of the upper slurry 1 and the lower slurry 2. The d(0.1), d(0.5), and d(0.9) of the two slurries are d1(0.1), d1(0.5) and d1(0.9), d2(0.1), d2(0.5) and d2(0.9) respectively. The homogeneity coefficient of the slurry β = |d2(0.1)-d1(0.1)|+|d2(0.5)-d1(0.5)|+|d2(0.9)-d1(0.9)|;

[0014] h. Pour the slurry prepared in step b into a closed test mold D and cure it with the film for 28 days. Take out the test block in the test mold and cut it into 40*40*40 test blocks according to the upper, middle and lower layers. Weigh them respectively and test their strength, which is calculated as m 上 , m 中 、m 下 , S 上 , S 中 and S 下 ;

[0015] i. The slurry homogeneity index γ is obtained according to the following formula: 上 -(m 上 +m 中 +m 下 ) / 3] 2 +[m 中 -(m 上 +m 中 +m 下 ) / 3] 2 +[m 下 -(m 上 +m 中 +m 下 ) / 3] 2; Homogeneity index μ = [S 上 -(S 上 +S 中 +S 下 ) / 3] 2 +[S 中 -(S 上 +S 中 +S 下 ) / 3] 2 +[S 下 -(S 上 +S 中 +S 下 ) / 3] 2 ;

[0016] j. Data collation: slurry homogeneity index Y = α*β*γ*μ / 1000.

[0017] In one of the preferred solutions of the present invention, the stirring speed of the slow stirring in step b is 500 r / min, the stirring speed of the slurry stirring pot is adjusted to 1000-2000 r / min, and the stirring is continued for 5-10 minutes.

[0018] In one of the preferred solutions of the present invention, the standing time in step c is 30 min-60 min.

[0019] One of the preferred solutions of the present invention is that in step f, the cylindrical container C has a diameter of 100mm-200mm and a height of 100mm-200mm, and a temporary blocking device is provided in the middle of the container C to divide the slurry in the container C into two parts in the upper and lower directions.

[0020] In one of the preferred solutions of the present invention, the test mold D in step h is 40 mm long, 40 mm wide, 160 mm high, and has a closed bottom.

[0021] In summary, the beneficial effects of the present invention are:

[0022] 1. The test method for evaluating slurry homogeneity of the present invention is suitable for measuring slurry homogeneity. For high-fluidity slurry composed of various cementitious materials, water seepage and stratification of grouting materials can be fundamentally eliminated by controlling the slurry homogeneity index.

[0023] 2. The method of the present invention is used to determine the homogeneity of the slurry, which fills the gap in the current standard for determining the homogeneity of the slurry and provides a control index basis for the design of the grouting material mix ratio. DETAILED DESCRIPTION

[0024] (1) Testing environment requirements:

[0025] Temperature 20±2℃; relative humidity not less than 50%.

[0026] (2) Main instruments and equipment:

[0027] Grouting material mixer; speed 0-2000r / min

[0028] Balance: range 5000g, accuracy 0.1g;

[0029] Balance: range 200g, accuracy 0.01g;

[0030] Cylindrical containers A and B: 2L;

[0031] Cylindrical container C: The container has a diameter of 100mm-200mm and a height of 100mm-200mm, and a temporary blocking device is provided in the middle of the cylindrical container C to divide the slurry in the container C into two parts in the vertical direction;

[0032] Test mold: 40mm long, 40mm wide, 160mm high, closed bottom.

[0033] (3) Test steps:

[0034] a. Weigh 3500g of cementitious materials according to the combination ratio of cementitious materials used in the slurry mix ratio. Calculate the amount of water and admixtures according to the mix ratio of water-binder ratio and admixture dosage, and weigh them. Weigh the admixture to an accuracy of 0.01g, and weigh other materials to an accuracy of 0.1g;

[0035] b. Pour water into the grouting material stirring pot, start the grouting material stirring pot and stir slowly at a speed of 500r / min. Mix the cementitious material and water reducing agent evenly and add them into the stirring pot. After adding, adjust the speed of the grouting material mixer to 1000-2000r / min and stir for 5-10 minutes;

[0036] c. Prepare two identical cylindrical containers A and B, weigh the weight M1 of container A, slowly and evenly pour the prepared slurry into container A, then immediately pour it into container B, let it stand for 30-60 minutes, and then pour it out;

[0037] d. Weigh the total mass of container A + the slurry attached to the container wall M2, and weigh the total mass of container B + the slurry attached to the container wall M3;

[0038] e. Data processing: Calculate the mass of the remaining slurry in the container according to the following formula: m = (M3-M1)-(M2-M1) = M3-M2, and calculate the homogeneity coefficient α according to the following formula: α = m / (M2-M1);

[0039] f. Prepare a cylindrical container C that can be separated into upper and lower parts, pour the slurry into the container C, let it stand for 30-60 minutes, and then separate the upper and lower slurries to obtain an upper slurry 1 and a lower slurry 2;

[0040] g. Perform particle size analysis on the upper slurry 1 and the lower slurry 2 respectively to obtain the particle size analysis results of the upper slurry 1 and the lower slurry 2. The d(0.1), d(0.5), and d(0.9) of the two slurries are d1(0.1), d1(0.5) and d1(0.9), d2(0.1), d2(0.5) and d2(0.9) respectively. The homogeneity coefficient of the slurry β = |d2(0.1)-d1(0.1)|+|d2(0.5)-d1(0.5)|+|d2(0.9)-d1(0.9)|;

[0041] h. Pour the slurry prepared in step b into a closed test mold D and cure it with the film for 28 days. Take out the test block in the test mold and cut it into 40*40*40 test blocks according to the upper, middle and lower layers. Weigh them respectively and test their strength, which is calculated as m 上 , m 中 、m 下 , S 上 , S 中 and S 下 ;

[0042] i. The slurry homogeneity index γ is obtained according to the following formula: 上 -(m 上 +m 中 +m 下 ) / 3] 2 +[m 中 -(m 上 +m 中 +m 下 ) / 3] 2 +[m 下 -(m 上 +m 中 +m 下 ) / 3] 2 ; Homogeneity index μ = [S 上 -(S 上 +S 中 +S 下 ) / 3] 2 +[S 中 -(S 上 +S 中 +S 下 ) / 3] 2 +[S 下 -(S 上 +S 中 +S 下 ) / 3] 2 ;

[0043] j. Data collation: Slurry homogeneity index Y = α*β*γ*μ / 1000. The smaller the homogeneity coefficient, the better the slurry homogeneity.

Claims

1. A test method for evaluating slurry homogeneity, characterized in that: The following steps are involved: Pour the prepared slurry into a cylindrical container, cover it with plastic wrap and let it stand, pour out the slurry in the container after standing, weigh the weight of the remaining slurry in the container, and test the particle size distribution of the upper and lower layers of the poured slurry, then put it into a mold for curing, cut it into three parts after curing, test their weight and compressive strength respectively, and obtain the homogeneity index, and judge the homogeneity of the slurry by the homogeneity index; The test method for evaluating slurry homogeneity specifically comprises the following steps: a. Weigh the cementitious materials according to the combination ratio of the cementitious materials used in the slurry mix ratio, calculate the amount of water and admixtures used and weigh them according to the water-binder ratio and admixture dosage of the mix ratio; b. Pour water into the grouting material stirring pot, start the grouting material stirring pot to stir slowly, mix the gelling material and water reducing agent evenly and add them into the stirring pot. After the addition is completed, adjust the stirring speed of the grouting material stirring pot and continue stirring; c. Prepare two identical cylindrical containers A and B, weigh the weight M1 of container A, slowly and evenly pour the prepared slurry into container A, then immediately pour it into container B, let it stand and then pour it out; d. Weigh the total mass of container A + the slurry attached to the container wall M2, and weigh the total mass of container B + the slurry attached to the container wall M3; e. Calculate the mass of the remaining slurry in the container m = (M3-M1) - (M2-M1) = M3-M2 according to the following formula, and calculate the homogeneity coefficient α according to the following formula: α = m / (M2-M1); f. Prepare a cylindrical container C that can be separated into upper and lower parts, pour the slurry into the container C, let it stand for a period of time, and then separate the upper and lower slurries to obtain an upper slurry 1 and a lower slurry 2; g. Perform particle size analysis on the upper slurry 1 and the lower slurry 2 respectively to obtain the particle size analysis results of the upper slurry 1 and the lower slurry 2. The d(0.1), d(0.5), and d(0.9) of the two slurries are d1(0.1), d1(0.5) and d1(0.9), d2(0.1), d2(0.5) and d2(0.9), respectively. The homogeneity coefficient of the slurry β=|d2(0.1)-d1(0.1)|+|d2(0.5)-d1(0.5)|+|d2(0.9)-d1(0.9)|; wherein d(0.1) is the particle size value corresponding to the cumulative particle size distribution percentage of 10%, d(0.5) is the particle size value corresponding to the cumulative particle size distribution percentage of 50%, and d(0.9) is the particle size value corresponding to the cumulative particle size distribution percentage of 90%; h. Pour the slurry prepared in step b into a closed test mold D and cure it with the film for 28 days. Take out the test block in the test mold and cut it into 40*40*40 test blocks according to the upper, middle and lower layers. Weigh them respectively and test their strength, which is calculated as m 上 , m 中 、m 下 , S 上 , S 中 and S 下 ; i. The slurry homogeneity index γ is obtained according to the following formula: 上 -(m 上 +m 中 +m 下 ) / 3] 2 +[m 中 -(m 上 +m 中 +m 下 ) / 3] 2 +[m 下 -(m 上 +m 中 +m 下 ) / 3] 2 ; Homogeneity index µ=[S 上 -(S 上 +S 中 +S 下 ) / 3] 2 +[S 中 -(S 上 +S 中 +S 下 ) / 3] 2 +[S 下 -(S 上 +S 中 +S 下 ) / 3] 2 ; j. Data collation: slurry homogeneity index Y=α*β*γ*µ / 1000.

2. A test method for evaluating slurry homogeneity according to claim 1, characterized in that: The stirring speed of the slow stirring in step b is 500 r / min, and the stirring speed of the slurry stirring pot is adjusted to 1000-2000 r / min, and the stirring is continued for 5-10 minutes.

3. A test method for evaluating slurry homogeneity according to claim 1, characterized in that: The standing time in step c is 30 min-60 min.

4. A test method for evaluating slurry homogeneity according to claim 1, characterized in that: In the step f, the cylindrical container C has a diameter of 100 mm to 200 mm and a height of 100 mm to 200 mm. A temporary blocking device is provided in the middle of the container C to divide the slurry in the container C into two parts in the vertical direction.

5. A test method for evaluating slurry homogeneity according to claim 1, characterized in that: In the step h, the test mold D has a length of 40 mm, a width of 40 mm, a height of 160 mm, and a closed bottom.