Method for rapidly testing pozzolanic activity of pozzolanic material
By combining zeta potential testing with curve fitting, the problem of time-consuming activity testing of volcanic ash materials has been solved, achieving rapid, simple, and accurate activity testing.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ANHUI CONCH GRP
- Filing Date
- 2026-01-29
- Publication Date
- 2026-05-08
AI Technical Summary
Existing methods for detecting the volcanic ash activity of volcanic ash materials are cumbersome and time-consuming, failing to meet the need for rapid testing.
The method of combining zeta potential testing with fitting curves was adopted. By preparing simulated pore solutions, dispersing samples, and quantitatively taking sample suspensions for zeta potential testing, the intensity activity index was quickly determined using the fitting curves.
It enables rapid, simple, and reliable testing of the pozzolanic activity of pozzolanic materials, reduces human interference, significantly shortens testing time, and provides highly accurate results.
Smart Images
Figure CN121994560A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of cement technology, specifically relating to a method for rapidly testing the pozzolanic activity of pozzolanic materials. Background Technology
[0002] Pozzolanic materials are a type of siliceous and / or aluminous material. While they possess little to no cementitious properties, after fine grinding, they can react with Ca(OH)₂ at room temperature in the presence of moisture to form cementitious products. Utilizing pozzolanic materials not only reduces the proportion of cement clinker used, achieving waste-saving, cost-effective, energy-efficient, and carbonation-based preparation of cementitious materials, but also improves the durability properties of concrete, such as impermeability and resistance to chemical erosion, while ensuring its mechanical properties.
[0003] The proportion of pozzolanic materials replacing cement depends on the pozzolanic activity of these materials. Currently, the Chinese standards "Pozzolanic Materials for Cement" (GB / T 2847-2005) and "Natural Pozzolanic Materials for Cement Mortar and Concrete" (JC / T 315-2011) specify two methods for testing pozzolanic activity: the lime absorbance method and the strength activity index method. The lime absorbance method is relatively cumbersome and susceptible to human error, while the strength activity index method is simple to operate and directly reflects the contribution of pozzolanic materials to the strength of the cementitious system. Therefore, the strength activity index method has become the most commonly used method for evaluating the performance of pozzolanic materials. However, the strength activity index method has a long testing cycle, which cannot meet the requirements for rapid testing of pozzolanic activity. Therefore, how to quickly, easily, and reliably test the pozzolanic activity of pozzolanic materials has become an urgent technical problem to be solved. Summary of the Invention
[0004] The purpose of this invention is to provide a method for rapidly testing the volcanic ash activity of volcanic ash materials, thereby solving the technical problem of long testing cycles in existing technologies.
[0005] The method for rapidly testing the volcanic ash activity of volcanic ash materials includes: Step 1: Prepare a simulated pore solution for cement slurry; Step 2: Disperse samples of several types of volcanic ash materials into corresponding simulated pore solutions to obtain corresponding sample suspensions; Step 3: Take a quantitative sample suspension of each sample for zeta potential testing; Step 4: Fit the Zeta potential and corresponding intensity activity index of each sample to obtain the fitting curve; Step 5: Take the sample to be tested and test the Zeta potential of the sample according to the procedures in Steps 1 to 3. Determine the intensity activity index of the sample based on the fitted curve.
[0006] Preferably, the pozzolanic materials used for fitting include slag powder, fly ash, silica fume, coal gangue, pumice, and incineration sludge ash. In step four, the 28-day strength activity index used for fitting is measured using the national standard calculation method for the strength activity index.
[0007] Preferably, in step one, the components of the simulated pore solution include calcium sulfate dihydrate, calcium sulfate dihydrate, potassium sulfate, potassium hydroxide, and water.
[0008] Preferably, in step two, the simulated pore solution containing the volcanic ash material sample is subjected to ultrasonic treatment.
[0009] Preferably, in step two, one part of each of the various volcanic ash materials used for fitting, 100 parts of the simulated pore solution, and an ultrasonic treatment time of 2.5 min are used; in step three, the amount of each sample suspension is 1 mL.
[0010] Preferably, in step three, the Zeta potential test is performed under a constant temperature of 25 °C, and the test is started after the suspension is injected into the measuring cell and kept at a constant temperature for 1 min.
[0011] Preferably, for the sample used for fitting and the sample to be tested, the zeta potential test of each sample is repeated 3 times, and the arithmetic mean of the measured results is taken as the final result.
[0012] Preferably, in step one, 1.72 parts of calcium sulfate dihydrate, 6.96 parts of sodium sulfate, 4.75 parts of potassium sulfate and 7.12 parts of potassium hydroxide are taken in sequence and dissolved in 1000 parts of deionized water to prepare a simulated pore solution for cement slurry.
[0013] The technical advantages of this invention are as follows: Compared with existing lime absorbance value methods and intensity activity index methods, this invention, except for the time-consuming existing technology of testing the intensity activity index of each sample used for fitting during the initial determination of the fitting curve, directly uses the Zeta potential detection method for the actual test samples. After obtaining the Zeta potential data, the corresponding intensity activity index is calculated using the fitting curve. The correlation between the intensity activity index and the Zeta potential has been obtained in the previous fitting process and has been experimentally verified. Therefore, it enables rapid and simple testing, greatly reducing the detection time and is less susceptible to human interference. The data measured by this method has a high positive correlation with the intensity activity index method, and has broad application prospects. Attached Figure Description
[0014] Figure 1 This is a basic flowchart of a method for rapidly testing the volcanic ash activity of volcanic ash materials according to the present invention.
[0015] Figure 2 This is a fitted curve of the strength activity index and Zeta potential of the volcanic ash material in Example 1 of the present invention. Detailed Implementation
[0016] The following detailed description of the embodiments, with reference to the accompanying drawings, will further illustrate the specific implementation of the present invention, in order to help those skilled in the art to have a more complete, accurate, and in-depth understanding of the inventive concept and technical solution of the present invention.
[0017] like Figures 1-2 As shown, the present invention provides a method for rapidly testing the volcanic ash activity of volcanic ash materials, comprising the following steps.
[0018] Step 1: Prepare a simulated pore solution for cement slurry.
[0019] In this step, the simulated pore solution consists of calcium sulfate dihydrate, calcium sulfate dihydrate, potassium sulfate, potassium hydroxide, and water.
[0020] In this embodiment, the specific steps are as follows: 1.72 parts of calcium sulfate dihydrate, 6.96 parts of sodium sulfate, 4.75 parts of potassium sulfate, and 7.12 parts of potassium hydroxide are sequentially dissolved in 1000 parts of deionized water to prepare a simulated pore solution for cement slurry. The reagent purity of the above components should reach analytical grade. To ensure the stability of the simulated pore solution, the solution must be prepared at least 24 hours before the start of the test.
[0021] Step 2: Add samples of several types of volcanic ash materials to the corresponding simulated pore solutions for dispersion to obtain the corresponding sample suspensions.
[0022] In this step, one part of each of several commonly used volcanic ash materials is selected and dispersed in 100 parts of a prepared simulated pore solution.
[0023] In this embodiment, the specific steps are as follows: Six types of pozzolanic materials are used, including one part each of slag powder, fly ash, silica fume, coal gangue, pumice, and incinerated sludge ash, which are dispersed in 100 parts of a prepared simulated pore solution. The XRF test results of the above six pozzolanic materials are shown in Table 1.
[0024] Table 1: XRF Test Results of the Selected Volcanic Ash Material in Step Two
[0025] To ensure effective dispersion, this step involves ultrasonically treating the simulated pore solution containing the volcanic ash material sample for 2.5 minutes to ensure that the powder is fully and uniformly dispersed in the solution.
[0026] Step 3: Take a quantitative sample suspension of each sample for zeta potential testing.
[0027] In this step, 1 mL of each dispersed sample suspension is injected into the measuring cell for zeta potential testing.
[0028] In this embodiment, to ensure the comparability and consistency of the test results of each sample, the Zeta potential test in this step should be carried out under constant temperature conditions of 25 ℃, and the test should be started after the suspension is injected into the measuring cell and kept at constant temperature for 1 min.
[0029] Step 4: Fit the Zeta potential of each sample to the determined intensity activity index to obtain the fitting curve.
[0030] In this step, the Zeta potential (tested in step three) and the 28-day strength activity index (tested using existing techniques) of the selected volcanic ash material are fitted to obtain the fitting curve of the Zeta potential and the 28-day strength activity index.
[0031] In this embodiment, the specific step is as follows: The six types of pozzolanic materials mentioned above are tested according to the test methods specified in "Natural Pozzolanic Materials for Cement Mortar and Concrete" (JC / T315-2011) to obtain the corresponding 28-day strength activity index. The strength activity index and Zeta potential of the selected pozzolanic materials are fitted to obtain the fitting curve of strength activity index versus Zeta potential, as shown below. Figure 2 As shown in Table 2, the corresponding data for the intensity activity index and zeta potential are presented.
[0032] Table 2: Zeta potential and 28-day strength activity index of common volcanic ash materials
[0033] Step 5: Take the sample to be tested and test the Zeta potential of the sample according to the procedures in Steps 1 to 3. Determine the intensity activity index of the sample based on the fitted curve.
[0034] In this step, a simulated pore solution of cement paste is first prepared according to the method in step one. One part of the volcanic ash material to be tested is then dispersed in 100 parts of the prepared simulated pore solution. Next, a quantitative sample suspension of the test sample is taken for Zeta potential testing. After testing the Zeta potential of the volcanic ash material, its strength activity index can be determined based on the fitted curve.
[0035] In this embodiment, the specific steps are as follows: volcanic rock powder taken from Lhasa, Tibet, before and after calcination at 700℃ is selected as the volcanic ash material to be tested, and the test is performed according to the method in step five. As verification, its corresponding 28-day strength activity index is also tested using the test method (i.e., the national standard calculation method) specified in "Natural Volcanic Ash Materials for Cement Mortar and Concrete" (JC / T 315-2011).
[0036] The Zeta potential (tested using the method in step three), 28-day strength activity index (tested using the test method specified in "Natural Volcanic Ash Materials for Cement Mortar and Concrete" (JC / T 315-2011) of volcanic rock powder (before and after calcination at 700 ℃) and the results obtained through... Figure 1 The 28-day intensity activity index (i.e. the result obtained in step five of this method) calculated by substituting the fitted relationship is shown in Table 3.
[0037] Table 3. Zeta potential and 28-day strength activity index of volcanic rock powder before and after calcination
[0038] As shown in the table above, the 28-day strength activity indices of volcanic rock powder before and after calcination, obtained according to the standard "Natural Volcanic Ash Materials for Cement Mortar and Concrete" (JC / T 315-2011), are 62.7% and 78.5%, respectively. However, the 28-day strength activity indices calculated from the fitted curve are 59.6% and 77.2%, respectively, with relative errors of 4.94% and 1.66%.
[0039] To ensure the reliability of the results, the zeta potential test of each sample should be repeated 3 times, whether it is the sample used for fitting or the sample to be tested in the actual test, and the arithmetic mean of the measured results should be taken as the final result.
[0040] In summary, the above results demonstrate that this testing method possesses high feasibility and accuracy. Furthermore, by using the zeta potential of the sample as a key detection step for fitting, the actual time required to detect the zeta potential is significantly shorter than that of the existing 28-day intensity activity index testing method. After preparing the solution, zeta potential data can be obtained in as little as a few minutes for fitting.
[0041] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other occasions without modification, are all within the protection scope of the present invention.
Claims
1. A method for rapidly testing the volcanic ash activity of volcanic ash materials, characterized in that, include: Step 1: Prepare a simulated pore solution for cement slurry; Step 2: Disperse samples of several types of volcanic ash materials into corresponding simulated pore solutions to obtain corresponding sample suspensions; Step 3: Take a quantitative sample suspension of each sample for zeta potential testing; Step 4: Fit the Zeta potential and corresponding intensity activity index of each sample to obtain the fitting curve; Step 5: Take the sample to be tested and test the Zeta potential of the sample according to the procedures in Steps 1 to 3. Determine the intensity activity index of the sample based on the fitted curve.
2. The method for rapidly testing the volcanic ash activity of volcanic ash materials according to claim 1, characterized in that, The pozzolanic materials used for fitting include slag powder, fly ash, silica fume, coal gangue, pumice, and incineration sludge ash. In step four, the 28-day strength activity index used for fitting is measured using the national standard calculation method for the strength activity index.
3. The method for rapidly testing the volcanic ash activity of volcanic ash materials according to claim 2, characterized in that, In step one, the simulated pore solution consists of calcium sulfate dihydrate, calcium sulfate dihydrate, potassium sulfate, potassium hydroxide, and water.
4. The method for rapidly testing the volcanic ash activity of volcanic ash materials according to claim 1, characterized in that, In step two, the simulated pore solution containing the volcanic ash material sample is subjected to ultrasonic treatment.
5. A method for rapidly testing the volcanic ash activity of volcanic ash materials according to claim 1, characterized in that, In step two, one part of each of the various volcanic ash materials used for fitting and 100 parts of the simulated pore solution were used, and the ultrasonic treatment time was 2.5 min. In step three, the amount of each sample suspension used was 1 mL.
6. A method for rapidly testing the volcanic ash activity of volcanic ash materials according to claim 5, characterized in that, In step three, the Zeta potential test is performed under a constant temperature of 25 °C, and the test is started after the suspension is injected into the measurement cell and kept at a constant temperature for 1 min.
7. The method for rapidly testing the volcanic ash activity of volcanic ash materials according to claim 6, characterized in that, For the samples used for fitting and the samples to be tested, the zeta potential test of each sample was repeated 3 times, and the arithmetic mean of the measured results was taken as the final result.
8. The method for rapidly testing the volcanic ash activity of volcanic ash materials according to claim 4, characterized in that, In step one, 1.72 parts of calcium sulfate dihydrate, 6.96 parts of sodium sulfate, 4.75 parts of potassium sulfate and 7.12 parts of potassium hydroxide were taken in sequence and dissolved in 1000 parts of deionized water to prepare a simulated pore solution for cement slurry.