Production and processing technology of a highly water-permeable environmental protection permeable brick

Abstract

This application relates to the technical field of permeable brick production, and specifically relates to a production and processing technology for highly permeable environmental protection permeable bricks. The technology includes: uniformly mixing the pretreated aggregate with fly ash and cement to obtain a mixed solid, pouring the uniformly mixed water and water reducer into the mixed solid, and stirring evenly to obtain a mixed slurry; pressing and molding the mixed slurry and then demolding to obtain a brick blank, where the brick blank includes a brick blank sample and a brick blank to be tested; drying the brick blank, and collecting terahertz spectral data at each position and each moment of the brick blank during the drying process; determining the pore feature vectors at each moment; testing the splitting tensile strength and flexural strength of the brick blank sample at each moment; combining a multiple linear regression model to obtain a regression equation, judging the drying time for the brick blank to be tested, and performing normal temperature curing on the dried brick blank to be tested to obtain a permeable brick. This application improves the production performance of permeable bricks.

Description

Technical Field

[0001] The present application relates to the technical field of permeable brick production, and specifically relates to a production and processing technology for highly permeable environmental protection permeable bricks. Background Art

[0002] A permeable brick is a new type of green environmental protection building material formed by high-pressure molding using environmental protection materials such as cement, sand, ore, and pulverized coal. It has good water permeability, can quickly infiltrate the accumulated rainwater into the groundwater system after rain, is beneficial to reducing the urban heat island effect, flood control, water conservation, etc., and is widely used in the construction of sponge cities.

[0003] In the production and processing process of permeable bricks, a relatively high target porosity can be achieved for permeable bricks according to the design calculation method of the permeable brick mix ratio, and then a mix ratio of permeable brick ingredients with high water permeability can be obtained. However, too high a porosity will reduce the strength of the permeable brick. Therefore, it is necessary to adjust the parameters during the drying process of the permeable brick, such as the drying time, to control the shrinkage of the pores in the permeable brick and improve the strength of the finished permeable brick.

[0004] However, the existing technology usually conducts strength tests on the finished permeable bricks, such as splitting tensile strength tests and flexural strength tests, etc., and adjusts the drying time of the permeable bricks based on this. However, the finished product test of the permeable brick can only reflect the final result, has a certain lag, and cannot deeply analyze the influence of the drying process of the permeable brick on its strength. Therefore, it is difficult to adjust the parameters of the drying process of the permeable brick in a timely manner, affecting the performance of the permeable brick. Summary of the Invention

[0005] In order to solve the above technical problems, the present application provides a production and processing technology for highly permeable environmental protection permeable bricks to solve the existing problems.

[0006] The production and processing technology for highly permeable environmental protection permeable bricks of the present application adopts the following technical solutions:

[0007] An embodiment of the present application provides a production and processing technology for highly permeable environmental protection permeable bricks, and the technology includes:

[0008] Mix the pretreated aggregate with fly ash and cement evenly to obtain a mixed solid, pour the evenly mixed water and water reducer into the mixed solid, and stir evenly to obtain a mixed slurry;

[0009] Press and mold the mixed slurry and then demold it to obtain a brick blank, and the brick blank includes a brick blank sample and a brick blank to be tested;

[0010] Perform a drying treatment on the brick blank, collect terahertz spectral data of each position and each moment of the brick blank during the drying treatment; based on the similarity of the terahertz spectral data of different positions at each moment, divide the terahertz spectral data of all positions at each moment into each clustering cluster;

[0011] Using the difference in the absorption coefficients between each terahertz spectral data in each clustering cluster and the remaining terahertz spectral data, determine the absorption characteristic values of each terahertz spectral data in each clustering cluster;

[0012] Based on the pore positions on the surface of the brick blank, use the absorption characteristic values to obtain a first data point set from the terahertz spectral data at all positions at each moment;

[0013] According to the number of terahertz spectral data in the first data point set, determine the first characteristic value of the pores at each moment; based on the position differences of different pores on the surface of the brick blank, divide all the terahertz spectral data in the first data point set at each moment into various categories;

[0014] Record the number of the divided categories as the second characteristic value of the pores; determine the proportion of each type of terahertz spectral data in the terahertz spectral data at all positions at each moment, calculate the mean value of the proportions of the terahertz spectral data of the preset number of categories at each moment, and record it as the third characteristic value of the pores. Combine the first characteristic value of the pores to determine the pore shrinkage vector at each moment;

[0015] Based on the difference between the pore shrinkage vectors at each moment and its adjacent moment, combine the first characteristic value of the pores, the second characteristic value of the pores, and the third characteristic value of the pores to obtain the pore characteristic vector at each moment;

[0016] Test the splitting tensile strength and flexural strength of the brick blank samples at each moment; use the pore characteristic vectors, splitting tensile strength, and flexural strength at each moment, combine with a multiple linear regression model to obtain a regression equation, and determine the drying time for the brick blank to be tested;

[0017] Carry out normal temperature curing on the brick blank to be tested after drying treatment to obtain a permeable brick.

[0018] In one embodiment, the pretreatment is to put the aggregate into a crusher for crushing, screen out the aggregate part with a particle size of 5 - 10 mm, and after washing the screened aggregate, dry it.

[0019] In one embodiment, the mixing ratio of cement, aggregate, fly ash, water reducing agent, and water is 451:1340:49:4.1:142.

[0020] In one embodiment, the pressing and forming is carried out under a pressure of 4 - 12 MPa and the pressure is maintained for 30 - 80 s.

[0021] In one embodiment, the drying treatment includes: drying treatment at a temperature of 75 - 105 °C, a humidity of 40% - 70%, and a ventilation speed of 0.5 - 1.5 m / s.

[0022] In one embodiment, the determination of the absorption eigenvalue includes:

[0023] Extract the absorption coefficient spectra of the terahertz spectral data in each clustering cluster, calculate the mean value of the amplitudes corresponding to all frequencies in the absorption coefficient spectrum, and calculate the difference between the mean value of the terahertz spectral data in each clustering cluster and the mean value of the remaining terahertz spectral data;

[0024] The absorption eigenvalue is the mean value of the differences of all terahertz spectral data in each clustering cluster.

[0025] In one embodiment, the determination of the first pore eigenvalue includes:

[0026] Determine the segmentation threshold of the absorption eigenvalues of the terahertz spectral data at all positions at each moment, and form a first data point set with the terahertz spectral data whose absorption eigenvalues are less than the segmentation threshold at each moment;

[0027] The first pore eigenvalue is the proportion of the number of terahertz spectral data in the first data point set at each moment in all terahertz spectral data at each moment.

[0028] In one embodiment, the determination of the pore feature vector includes:

[0029] Calculate the difference between the pore shrinkage vectors at each moment and the previous moment, denoted as the first difference, and form the pore feature vector at each moment by combining the first pore eigenvalue, the second pore eigenvalue, the third pore eigenvalue, and the first difference at each moment.

[0030] In one embodiment, the determination of the time for drying the brick blank to be measured includes:

[0031] Take the splitting tensile strength and flexural strength of the brick blank sample as the dependent variables respectively, and take the pore feature vector of the brick blank sample as the independent variable to obtain the regression equation corresponding to the splitting tensile strength and the regression equation corresponding to the flexural strength;

[0032] Input the pore feature vectors at each moment of the brick blank to be measured into each regression equation to obtain the splitting tensile strength and flexural strength at each moment of the brick blank to be measured. When both the splitting tensile strength and flexural strength of the brick blank to be measured are greater than the preset threshold, stop drying; otherwise, continue drying until the preset drying time is reached.

[0033] This application has at least the following beneficial effects:

[0034] This application collects terahertz spectral data of each position and each moment of the brick blank during the drying process; based on the similarity of the terahertz spectral data of different positions at each moment, divides the terahertz spectral data of all positions at each moment into each clustering cluster; enhances the real-time perception ability of the microscopic pore evolution of the brick blank; uses the difference in the absorption coefficients between each terahertz spectral data in each clustering cluster and the remaining terahertz spectral data to determine the absorption characteristic values of each terahertz spectral data in each clustering cluster; accurately distinguishes the moisture migration path and pore structure change in different drying stages, improves the accuracy of determining the pore position on the surface of the brick blank; based on the pore position on the surface of the brick blank, obtains the first data point set from the terahertz spectral data of all positions at each moment using the absorption characteristic value; the first data point set reflects the terahertz spectral data corresponding to the pore position on the surface of the brick blank, which helps to accurately grasp the pore generation situation on the surface of the brick blank and avoid misjudgment of the water permeability of the brick blank caused by ineffective pore statistics; determines the first pore characteristic value of each moment according to the number of terahertz spectral data in the first data point set; based on the position difference of different pores on the surface of the brick blank, divides all terahertz spectral data in the first data point set of each moment into various categories; determines the pore shrinkage vector of each moment by combining the proportion of each type of terahertz spectral data in the terahertz spectral data of all positions at each moment, the number of the divided categories, and the first pore characteristic value; the determination of the pore shrinkage vector realizes the refined characterization of the pore morphology and distribution, quantifies the anisotropic characteristics of pore shrinkage during the drying process, and improves the accuracy of time control during the drying process of the brick blank; based on the difference between the pore shrinkage vectors of each moment and its adjacent moment, combines the proportion, the number of categories, and the first pore characteristic value of each moment to obtain the pore characteristic vector of each moment; improves the predictability of the dynamic control during the drying process of the brick blank and accurately captures the correlation between the mechanical properties and pore evolution of the brick blank; tests the splitting tensile strength and flexural strength of the brick blank samples at each moment; uses the pore characteristic vector, splitting tensile strength, and flexural strength of each moment, combines with the multiple linear regression model to obtain the regression equation, judges the drying time for the brick blank to be tested, optimizes the accuracy and reliability of drying time control, and ensures that the permeable brick has both high strength and water permeability by determining the optimal drying end point, thus improving the production performance of the permeable brick. Description of the Drawings

[0035] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following described drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0036] Figure 1The flowchart of the production and processing technology of a highly water-permeable environmental protection permeable brick provided by this application;

[0037] Figure 2 It is the adjustment flowchart of the drying treatment time of the brick blank to be tested. Specific embodiments

[0038] In order to further elaborate on the technical means and effects adopted by this application to achieve the intended invention purpose, the following will combine the drawings and preferred embodiments to specifically describe the production and processing technology of a highly water-permeable environmental protection permeable brick proposed according to this application, its specific implementation methods, structures, features and effects in detail. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, the specific features, structures or characteristics in one or more embodiments can be combined in any suitable form.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs.

[0040] The following will specifically describe the specific scheme of the production and processing technology of a highly water-permeable environmental protection permeable brick provided by this application with reference to the drawings.

[0041] Example 1

[0042] Please refer to Figure 1 , which shows the flowchart of the production and processing technology of a highly water-permeable environmental protection permeable brick provided in Example 1 of this application. The process includes:

[0043] Step S001: Mix the pretreated aggregate with fly ash and cement evenly to obtain a mixed solid. Pour the evenly mixed water and water reducer into the mixed solid and stir evenly to obtain a mixed slurry.

[0044] In this embodiment, the production raw materials of the permeable brick mainly include cement, aggregate, fly ash, water reducer and water. The aggregate is waste construction waste. In this application, the cement is P.O42.5 ordinary Portland cement, the fly ash is secondary fly ash, and the water reducer is polycarboxylate water reducer.

[0045] First, perform pretreatment on the aggregate. Specifically:

[0046] Put the aggregate into a crusher for crushing, and use a square sieve to screen out the aggregate part with a particle size of 5-10 mm. Wash the screened aggregate with water and then put it into a drying oven for drying to remove impurities in the aggregate and obtain the pretreated aggregate.

[0047] Then, obtain the porosity and density of the pre-treated aggregate. At the same time, obtain the densities of cement, fly ash, water reducer, and water, and set the target porosity of the permeable bricks currently being produced. In this embodiment, in order to produce permeable bricks with high water permeability, the target porosity is set to 15%. To ensure that the performance of the produced permeable brick products meets the standards, the value of the target porosity should not be lower than 14%. Based on the obtained porosity, density, and the set target porosity, use the design calculation method for the mix proportion of permeable bricks to obtain the mixing ratio between the production raw materials of the permeable bricks. In this embodiment, the mixing ratio is cement: aggregate: fly ash: water reducer: water = 451:1340:49:4.1:142. Among them, the design calculation method for the mix proportion of permeable bricks is a well-known existing technology, and the specific process will not be elaborated here.

[0048] In this embodiment, according to the above mixing ratio, 1340 parts of aggregate, 49 parts of fly ash, and 451 parts of cement are mixed evenly to obtain a mixed solid. Then, 142 parts of water and 4.1 parts of water reducer are mixed evenly, and the evenly mixed liquid is poured into the evenly mixed mixed solid and put into a cement mortar mixer for stirring to obtain a uniformly stirred mixed slurry.

[0049] Step S002: After the mixed slurry is pressed into shape and demolded, a brick blank is obtained. The brick blank includes a brick blank sample and a brick blank to be tested.

[0050] Pour the stirred mixed slurry into a brick blank mold, place it on a hydraulic press, apply pressure at 4 MPa and hold the pressure for 30 s, and then demold to obtain a brick blank. Among them, the brick blank in this embodiment includes a brick blank sample and a brick blank to be tested. The brick blank sample is used for subsequent analysis in this embodiment, and the brick blank to be tested is used for the production of permeable bricks in this embodiment. The brick blank sample and the brick blank to be tested are collectively referred to as the brick blank.

[0051] Step S003: Dry the brick blank, and collect the terahertz spectral data of each position and each moment of the brick blank during the drying process; based on the similarity of the terahertz spectral data at different positions at each moment, divide the terahertz spectral data of all positions at each moment into each clustering cluster.

[0052] Use a drying device to dry the pressed brick blank at a temperature of 75 °C, a humidity of 40%, and a ventilation speed of 0.5 m / s. In this embodiment, the drying device is a drying chamber.

[0053] During the drying process of the brick blank, arbitrarily select a brick blank sample W. When the temperature of the drying chamber where the brick blank sample W is located reaches the set temperature, use the measurement probe of the terahertz spectrometer to collect the terahertz spectral data of each position and each moment on the surface of the brick blank sample W. In this embodiment, the acquisition time interval of the terahertz spectral data is 5 min, and the implementer can set it according to the actual situation and is not limited here in this embodiment.

[0054] Since different substances have different terahertz spectra, and the permeable brick blank is mainly formed by the aggregation of slurry particles in the mixed slurry obtained by mixing the three solid substances of cement, aggregate, and fly ash in its raw materials. Therefore, taking the terahertz spectral data at all positions collected at any time t as an example, the spectral angle between the terahertz spectral data at any two positions in the terahertz spectral data at all positions collected at time t is calculated using the SAM (Spectral Angle Mapper) algorithm, and the terahertz spectral data at all positions collected at time t is divided into 3 clustering clusters using the K-Means clustering algorithm, that is, K = 3 is set. Among them, the spectral angle is used as the measurement distance between the terahertz spectral data at any two positions in the K-Means clustering algorithm. The SAM algorithm and the K-Means clustering algorithm are both well-known existing technologies, and the specific process will not be elaborated here. Implementers can set other existing feasible clustering algorithms according to the actual situation, and this embodiment does not limit it here. The spectral angle reflects the similarity between the terahertz spectral data at two positions. Implementers can choose other existing feasible methods to reflect the similarity between the terahertz spectral data by themselves, and this embodiment does not limit it here.

[0055] Step S004, using the difference in the absorption coefficients between the terahertz spectral data in each clustering cluster and the remaining terahertz spectral data, determine the absorption characteristic values of the terahertz spectral data in each clustering cluster.

[0056] Since the permeable brick blank is formed by the aggregation of slurry particles in its mixed slurry, when the terahertz wave reaches the non-porous position on the brick blank surface, the terahertz wave will undergo a scattering effect at the non-porous position. And when the terahertz wave reaches a certain porous position on the brick blank surface, since the scattering effect of the pores on the terahertz wave is within the Rayleigh scattering mechanism, and the Rayleigh scattering has a low scattering intensity for light, and the hindrance of the pores to the terahertz wave is small, the energy of the terahertz wave scattered by the pores can be ignored, resulting in any porous position having a smaller absorption of the terahertz wave compared to the non-porous position with the same slurry composition as the any porous position, and further leading to any porous position having a smaller absorption coefficient of the terahertz wave compared to the non-porous position with the same slurry composition as the any porous position.

[0057] Based on the above analysis, taking any one of the three clustering clusters B at time t as an example, and taking any one terahertz spectral data b in the clustering cluster B as an example, the absorption coefficient spectrum of the terahertz time-domain spectrum of the terahertz spectral data b is extracted, and the mean value of the amplitudes corresponding to all frequencies in the absorption coefficient spectrum is calculated. The obtained mean value is denoted as the absorbance of the terahertz spectral data b, which is used to characterize the overall absorption degree of the terahertz wave by the surface position of the brick blank sample corresponding to the terahertz spectral data b. Among them, the extraction of the absorption coefficient spectrum of the terahertz time-domain spectrum is a well-known technology, and the specific process will not be elaborated here.

[0058] Calculate the differences between the absorbance of the terahertz spectral data b and the absorbance of each of the remaining terahertz spectral data in the clustering cluster B respectively. The mean value of all the obtained differences is used as the absorption eigenvalue of the terahertz spectral data b, which is used to evaluate whether the absorption degree of the terahertz wave by the surface position of the brick blank sample corresponding to the terahertz spectral data b is greater or smaller than that of the surface positions of the brick blank samples corresponding to the remaining terahertz spectral data with the same slurry composition as the terahertz spectral data b.

[0059] It should be understood that the difference reflects the overall difference level between the absorption coefficient of the terahertz spectral data b and the absorption coefficients of each of the remaining terahertz spectral data in the clustering cluster B. The difference represents the degree of difference between two variables, and specifically, it can be calculated by means such as the absolute value of the difference, the difference, the square of the difference, the ratio, etc. This embodiment does not limit it here.

[0060] Using the same calculation method as the absorption eigenvalue of the terahertz spectral data b, obtain the absorption eigenvalues of the terahertz spectral data in each clustering cluster at time t.

[0061] Step S005: Based on the pore positions on the brick blank surface, use the absorption eigenvalues to obtain the first data point set from the terahertz spectral data at all positions at each time, and determine the first pore eigenvalue at each time according to the number of terahertz spectral data in the first data point set; based on the position differences of different pores on the brick blank surface, divide all the terahertz spectral data in the first data point set at each time into various categories.

[0062] Take the absorption eigenvalues of the terahertz spectral data at all positions of the brick blank sample W at time t as the input of the maximum inter-class variance algorithm, and output the segmentation threshold v1. The set composed of all the terahertz spectral data with absorption eigenvalues less than the segmentation threshold v1 in the brick blank sample W at time t is used as the first data point set C at time t, which is used to characterize the terahertz spectral data corresponding to all the pore positions on the surface of the brick blank sample W. Among them, the maximum inter-class variance algorithm is a well-known technology, and the specific process will not be elaborated here. The implementer can select other existing feasible threshold segmentation algorithms by himself / herself. This embodiment does not limit it here.

[0063] Generally, the larger the proportion of the total area of the holes where all the pores are located on the surface of the permeable brick, the smaller the density of the permeable brick material usually is. The decrease in density often leads to a reduction in the strength of the permeable brick. Moreover, the larger the holes where the pores on the surface of the permeable brick are located, the looser the brick structure on the surface of the permeable brick, and the smaller the strength of the brick body. During the drying process of the permeable brick green body, the temperature of the green body gradually increases as the drying progresses until it reaches equilibrium with the hot air temperature in the drying chamber. At this time, the green body enters the constant-rate drying stage. In this stage, the moisture discharged during the drying of the green body is the moisture between the slurry particles in the green body, causing the green body to shrink. As a result, the holes where the pores on the surface of the green body are located become smaller due to the reduction in the distance between the slurry particles in the green body, thereby increasing the strength of the green body. However, if the drying time of the green body is too long, the surface of the green body will show drying cracks due to excessive drying. These cracks will increase the number of pores on the surface of the green body or enlarge the holes where the original pores are located, which will damage the integrity of the green body structure and further reduce the strength of the green body.

[0064] It should be noted that the pores on the surface of the permeable brick described in this embodiment correspond to the positions on the surface of the permeable brick, that is, one pore corresponds to one position, and a hole is composed of multiple pores, that is, one hole corresponds to multiple positions on the surface of the permeable brick.

[0065] Based on the above analysis, the ratio between the number of terahertz spectrum data in the first data point set C and the number of all terahertz spectrum data on the green body sample W at time t is used as the first pore characteristic value at time t to evaluate the proportion of the total area of the holes where all the pores are located on the surface of the green body sample W at time t.

[0066] Furthermore, in this embodiment, the DBSCAN clustering algorithm is used to cluster all the terahertz spectrum data in the first data point set C, obtaining multiple clustering clusters of the first data point set C, denoted as each class, which respectively correspond to the set composed of the terahertz spectrum data corresponding to each hole where the pores are located on the surface of the green body sample W. Among them, the Chebyshev distance corresponding to the two-dimensional position coordinates between the terahertz spectrum data in the first data point set C is used as the metric distance between the terahertz spectrum data in the DBSCAN clustering algorithm, and the neighborhood radius in the DBSCAN clustering algorithm is set to 1, so as to cluster the data points corresponding to a group of connected pore positions on the surface of the green body sample into one class. The DBSCAN clustering algorithm and the Chebyshev distance are both well-known technologies, and the specific process will not be elaborated here. Implementers can choose other existing feasible clustering algorithms and calculation methods of metric distances according to the actual situation. For example, fuzzy C-means clustering, Euclidean distance, etc. This embodiment does not make any restrictions here.

[0067] In step S006, based on the proportion of each type of terahertz spectrum data among the terahertz spectrum data at all positions at each moment, the number of the divided classes, and the first pore eigenvalue, determine the pore shrinkage vector at each moment; based on the difference between the pore shrinkage vectors at each moment and its adjacent moment, and combining the proportion, the number of classes, and the first pore eigenvalue at each moment, obtain the pore feature vector at each moment.

[0068] In this embodiment, the number of classes divided in the first data point set C, that is, the number of clustering clusters, is denoted as the second pore eigenvalue at time t, and is used to evaluate the number of holes where all pores are located on the surface of the brick blank sample W at the data acquisition time t.

[0069] Arrange all the clustering clusters in the first data point set C in descending order according to the number of terahertz spectrum data, obtain the first M clustering clusters after arrangement, and calculate the ratio of the number of terahertz spectrum data in each of the M clustering clusters to the number of all terahertz spectrum data on the surface of the brick blank sample W at time t, which is denoted as the first ratio and is used to evaluate the size of a hole where a pore corresponding to each of the M clustering clusters is located on the surface of the brick blank sample W. And take the mean value of all the first ratios obtained for the brick blank sample W at time t as the third pore eigenvalue at time t, which is used to evaluate the average size of the holes where all pores are located on the surface of the brick blank sample W at the data acquisition time t. Among them, screening out M clustering clusters is to avoid the influence of newly generated and smaller pores on the surface of the brick blank sample during its drying process on evaluating the average size of the holes where all pores are located on the surface of the brick blank sample. In this embodiment, M is set to 10, which is the preset number, and the implementer can set it according to the actual situation, but the value of M cannot exceed the number of clustering clusters divided in the first data point set of the brick blank sample at the initial acquisition time.

[0070] For the brick blank sample W, form the pore shrinkage vector at each moment with the first pore eigenvalue, the second pore eigenvalue, and the third pore eigenvalue at each moment. Among them, the first element in the pore shrinkage vector is the first pore eigenvalue, the second element is the second pore eigenvalue, and the third element is the third pore eigenvalue. Calculate the difference between the pore shrinkage vectors at each moment and its previous moment, which is denoted as the first difference. Specifically, calculate the difference between the elements at the same position in the pore shrinkage vectors at each moment and its previous moment. The first difference is used to evaluate the shrinkage situation of the holes where the pores on the surface of the brick blank sample W are located compared to the holes where the pores were located at the previous data acquisition time.

[0071] The first eigenvalue of pores, the second eigenvalue of pores, the third eigenvalue of pores, and the first difference at each moment of the green brick sample W are combined to form the pore feature vector of the green brick sample W at each moment. Among them, the first element in the pore feature vector is the first eigenvalue of pores, the second element is the second eigenvalue of pores, the third element is the third eigenvalue of pores, the fourth element is the first element in the first difference, the fifth element is the second element in the first difference, and the sixth element is the third element in the first difference. The pore feature vector is used to evaluate the total area ratio, quantity, average pore size, and pore shrinkage of the pores on the surface of the green brick sample W, so as to reflect the brick body strength of the green brick sample W at each moment.

[0072] Step S007: Test the splitting tensile strength and flexural strength of the green brick sample at each moment; use the pore feature vector, splitting tensile strength, and flexural strength at each moment, and combine them with the multiple linear regression model to obtain a regression equation, and judge the drying time of the green brick to be tested.

[0073] In this embodiment, N green brick samples are selected, and the splitting tensile strength and flexural strength of the green brick samples at each moment are tested. Specifically: taking the green brick sample W as an example, if it is necessary to determine the splitting tensile strength and flexural strength of the green brick sample at the first moment, then while obtaining the pore feature vector of the green brick sample at the first moment, the green brick sample W is taken out of the drying chamber without replacement, and the splitting tensile strength and flexural strength of the green brick sample W at the first moment are tested, so as to obtain the pore feature vector, splitting tensile strength, and flexural strength of the green brick sample W at the first moment. Further, in order to obtain the splitting tensile strength and flexural strength of the green brick sample at the second moment, while calculating the pore feature vector of any green brick sample in the drying chamber, it is taken out of the drying chamber without replacement, and its splitting tensile strength and flexural strength at the second moment are measured to obtain the pore feature vector, splitting tensile strength, and flexural strength of the green brick sample at the second moment. Similarly, the pore feature vector, splitting tensile strength, and flexural strength of the green brick sample at each moment can be obtained. Among them, the number of moments is equal to the number of green brick samples, that is, the pore feature vector, splitting tensile strength, and flexural strength of the green brick sample from the first moment to the Nth moment are obtained. In this embodiment, N = 100, and the implementer can set it according to the actual situation, and this embodiment does not limit it here. Among them, the test of the splitting tensile strength and flexural strength of the brick body of the permeable brick is a well-known technology, and the specific process will not be elaborated here.

[0074] Taking the pore feature vectors and splitting tensile strengths of the obtained brick blank samples at all times as the inputs of a multiple linear regression model, a regression equation Y1 is obtained to evaluate the internal relationship between the pore feature vectors and the splitting tensile strengths. Among them, each component in the pore feature vector is used as an independent variable in the multiple linear regression model, and the splitting tensile strength is used as the dependent variable in the multiple linear regression model. In addition, taking the pore feature vectors and flexural strengths of the obtained brick blank samples at all times as the inputs of the multiple linear regression model, a regression equation Y2 is obtained to evaluate the internal relationship between the pore feature vectors and the flexural strengths. Among them, each component in the pore feature vector is used as an independent variable in the multiple linear regression model, and the flexural strength is used as the dependent variable in the multiple linear regression model. The multiple linear regression model is a well-known technology, and the specific process will not be elaborated here.

[0075] For the brick blank to be tested, using the same calculation method as that for obtaining the pore feature vectors of the brick blank sample W at each time, the pore feature vectors of the brick blank to be tested at each time are determined. Taking the pore feature vectors of the brick blank to be tested at each time as the input of the regression equation Y1, the splitting tensile strengths of the brick blank to be tested at each time are output. Taking the pore feature vectors of the brick blank to be tested at each time as the input of the regression equation Y2, the flexural strengths of the brick blank to be tested at each time are output. If the splitting tensile strength and the flexural strength of the brick blank to be tested at a certain time are both greater than the preset threshold values, then the drying of the brick blank to be tested in the drying chamber is stopped at this time. Otherwise, continue drying until the preset drying duration is reached, so as to complete the adjustment of the drying treatment time of the brick blank to be tested. In this embodiment, the preset drying duration is 10 h, the preset threshold value of the splitting tensile strength is set to 2.4 MPa, and the preset threshold value of the flexural strength is 3.2 MPa. The implementer can set them according to the actual situation and the strength requirements of the permeable brick, and this embodiment does not limit it here. The flow chart of the adjustment of the drying treatment time of the brick blank to be tested is as Figure 2 shown.

[0076] Step S008, subjecting the brick blank to be tested after the drying treatment to normal temperature curing to obtain a permeable brick.

[0077] Subject the brick blank to be tested after the drying treatment to normal temperature curing for 5 days to obtain a finished permeable brick.

[0078] Embodiment 2

[0079] Please refer to Figure 1 , which shows the flow chart of the steps of a production and processing process of a highly permeable environmental protection permeable brick provided in Embodiment 2 of the present application. This process includes:

[0080] Step S001, uniformly mixing the pretreated aggregate with fly ash and cement to obtain a mixed solid, and pouring the uniformly mixed water and water reducing agent into the mixed solid and stirring evenly to obtain a mixed slurry.

[0081] In this embodiment, the raw materials for producing permeable bricks mainly include cement, aggregate, fly ash, water reducer, and water. The aggregate is waste construction waste. In this application, the cement is P.O42.5 ordinary Portland cement, the fly ash is secondary fly ash, and the water reducer is polycarboxylate water reducer.

[0082] First, pre-treat the aggregate. Specifically:

[0083] Put the aggregate into a crusher for crushing, and use a square sieve to screen out the aggregate part with a particle size of 5-10 mm. Wash the screened aggregate with water and then put it into a drying oven for drying to remove impurities in the aggregate, obtaining the pre-treated aggregate.

[0084] Then, obtain the porosity and density of the pre-treated aggregate, and at the same time obtain the densities of cement, fly ash, water reducer, and water, and set the target porosity of the permeable bricks currently being produced. In this embodiment, in order to produce permeable bricks with high water permeability, the target porosity is set to 25%. To ensure that the performance of the produced permeable brick finished products meets the standards, the value of the target porosity should not be less than 15%. Based on the obtained porosity, density, and the set target porosity, use the permeable brick mix proportion design calculation method to obtain the mixing ratio between the raw materials of the permeable bricks. In this embodiment, the mixing ratio is cement: aggregate: fly ash: water reducer: water = 451:1340:49:4.1:142. Among them, the permeable brick mix proportion design calculation method is a well-known prior art, and the specific process will not be elaborated.

[0085] In this embodiment, according to the above mixing ratio, 1340 parts of aggregate, 49 parts of fly ash, and 451 parts of cement are mixed evenly to obtain a mixed solid. Then, 142 parts of water and 4.1 parts of water reducer are mixed evenly, and the evenly mixed liquid is poured into the evenly mixed mixed solid and put into a cement mortar mixer for stirring to obtain a uniformly stirred mixed slurry.

[0086] Step S002: After pressing and demolding the mixed slurry, obtain a brick blank, and the brick blank includes a brick blank sample and a brick blank to be tested.

[0087] Pour the stirred mixed slurry into a brick blank mold, place it on a hydraulic press, apply pressure at 8 MPa and hold the pressure for 50 s, and then demold to obtain a brick blank. Among them, the brick blank in this embodiment includes a brick blank sample and a brick blank to be tested. The brick blank sample is used for subsequent analysis in this embodiment, and the brick blank to be tested is used for the production of permeable bricks in this embodiment. The brick blank sample and the brick blank to be tested are collectively referred to as the brick blank.

[0088] Step S003: Dry the brick blanks and collect the terahertz spectral data of each position of the brick blanks at each moment during the drying process; based on the similarity of the terahertz spectral data of different positions at each moment, divide the terahertz spectral data of all positions at each moment into each clustering cluster.

[0089] Use a drying device to dry the pressed brick blanks at a temperature of 95 °C, a humidity of 55%, and a ventilation speed of 1 m / s. In this embodiment, the drying device is a dryer.

[0090] During the drying process of the brick blanks, select an arbitrary brick blank sample W. When the temperature of the drying chamber where the brick blank sample W is located reaches the set temperature, use the measurement probe of the terahertz spectrometer to collect the terahertz spectral data of each position of the brick blank sample W at each moment. In this embodiment, the acquisition time interval of the terahertz spectral data is 5 min, and the implementer can set it according to the actual situation and is not limited in this embodiment.

[0091] Since different substances have different terahertz spectra, and the permeable brick blanks are mainly formed by the aggregation of slurry particles in the mixed slurry obtained by mixing the three solid substances of cement, aggregate, and fly ash in its raw materials. Therefore, taking the terahertz spectral data of all positions collected at any one t moment as an example, use the SAM (Spectral Angle Mapper) algorithm to calculate the spectral angle between the terahertz spectral data of any two positions in the terahertz spectral data of all positions collected at the t moment, and use the K-Means clustering algorithm to divide the terahertz spectral data of all positions collected at the t moment into 3 clustering clusters, that is, set K = 3. Among them, use the spectral angle as the measurement distance between the terahertz spectral data of any two positions in the K-Means clustering algorithm. The SAM algorithm and the K-Means clustering algorithm are both well-known existing technologies, and the specific process will not be elaborated. The implementer can set other existing feasible clustering algorithms according to the actual situation and is not limited in this embodiment.

[0092] The remaining steps are carried out according to the exactly same process and parameters as in Embodiment 1 of the present application. The difference is that finally, the brick blanks to be tested after drying treatment are cured at normal temperature for 6 days to obtain the finished permeable bricks.

[0093] Embodiment 3

[0094] Please refer to Figure 1 , which shows the process flow chart of a production and processing technology of a highly permeable environmental protection permeable brick provided by Embodiment 3 of the present application. This technology includes:

[0095] Step S001: Mix the pretreated aggregate with fly ash and cement evenly to obtain a mixed solid, pour the evenly mixed water and water reducer into the mixed solid, and stir evenly to obtain a mixed slurry.

[0096] In this embodiment, the production raw materials of the permeable brick mainly include cement, aggregate, fly ash, water reducing agent and water. The aggregate is waste construction waste. In this application, the cement is P.O42.5 ordinary Portland cement, the fly ash is secondary fly ash, and the water reducing agent is polycarboxylic acid water reducing agent.

[0097] First, pre-treat the aggregate. Specifically:

[0098] Put the aggregate into a crusher for crushing, and use a square sieve to screen out the aggregate part with a particle size of 5-10 mm. Wash the screened aggregate with water and then put it into a drying oven for drying to remove impurities in the aggregate, and obtain the pre-treated aggregate.

[0099] Then, obtain the porosity and density of the pre-treated aggregate, and at the same time obtain the densities of cement, fly ash, water reducing agent and water, and set the target porosity of the permeable brick currently produced. In this embodiment, in order to produce a permeable brick with high water permeability, the target porosity is set to 25%. To ensure that the performance of the produced permeable brick finished product meets the standards, the value of the target porosity should not be less than 15%. Based on the obtained porosity, density and the set target porosity, use the permeable brick mix proportion design calculation method to obtain the mixing ratio between the production raw materials of the permeable brick. In this embodiment, the mixing ratio is cement: aggregate: fly ash: water reducing agent: water = 451:1340:49:4.1:142. Among them, the permeable brick mix proportion design calculation method is a well-known prior art, and the specific process will not be elaborated.

[0100] In this embodiment, according to the above mixing ratio, 1340 parts of aggregate, 49 parts of fly ash and 451 parts of cement are mixed evenly to obtain a mixed solid. Then, 142 parts of water and 4.1 parts of water reducing agent are mixed evenly, and the evenly mixed liquid is poured into the evenly mixed mixed solid and put into a cement mortar mixer for stirring to obtain a uniformly stirred mixed slurry.

[0101] Step S002, press and mold the mixed slurry and then demold it to obtain a brick blank, and the brick blank includes a brick blank sample and a brick blank to be tested.

[0102] Pour the stirred mixed slurry into a brick blank mold, place it on a hydraulic press, apply pressure at 12 MPa and hold the pressure for 80 s, and then demold it to obtain a brick blank. Among them, the brick blank in this embodiment includes a brick blank sample and a brick blank to be tested. The brick blank sample is used for subsequent analysis in this embodiment, and the brick blank to be tested is used for the production of the permeable brick in this embodiment. The brick blank sample and the brick blank to be tested are collectively referred to as the brick blank.

[0103] Step S003: Dry the brick blanks and collect the terahertz spectral data of each position of the brick blanks at each moment during the drying process; based on the similarity of the terahertz spectral data of different positions at each moment, divide the terahertz spectral data of all positions at each moment into each clustering cluster.

[0104] Use a drying device to dry the pressed brick blanks at a temperature of 105 °C, a humidity of 70%, and a ventilation speed of 1.5 m / s. In this embodiment, the drying device is an oven.

[0105] During the drying process of the brick blanks, select an arbitrary brick blank sample W. When the temperature of the drying chamber where the brick blank sample W is located reaches the set temperature, use the measurement probe of the terahertz spectrometer to collect the terahertz spectral data of each position of the surface of the brick blank sample W at each moment. In this embodiment, the acquisition time interval of the terahertz spectral data is 5 min, and the implementer can set it by himself according to the actual situation, and this embodiment does not limit it here.

[0106] Since different substances have different terahertz spectra, and the permeable brick blanks are mainly formed by the aggregation of slurry particles in the mixed slurry obtained by mixing three solid substances, namely cement, aggregate, and fly ash, in its raw materials. Therefore, taking the terahertz spectral data of all positions collected at any one t moment as an example, use the SAM (Spectral Angle Mapper) algorithm to calculate the spectral angle between the terahertz spectral data of any two positions in the terahertz spectral data of all positions collected at the t moment, and use the K-Means clustering algorithm to divide the terahertz spectral data of all positions collected at the t moment into 3 clustering clusters, that is, set K = 3. Among them, use the spectral angle as the metric distance between the terahertz spectral data of any two positions in the K-Means clustering algorithm. The SAM algorithm and the K-Means clustering algorithm are both existing well-known technologies, and the specific process will not be described in detail. The implementer can set other existing feasible clustering algorithms by himself according to the actual situation, and this embodiment does not limit it here.

[0107] The remaining steps are exactly the same as the process and parameters in Embodiment 1 of this application. The difference is that finally, the tested brick blanks after drying treatment are cured at room temperature for 7 days to obtain the finished permeable bricks.

[0108] Comparative Example 1

[0109] In Comparative Example 1, during the production process of the permeable bricks, the drying time of the brick blanks is not adjusted, and the fixed drying time of 10 h is maintained. The rest of the steps and process parameters are exactly the same as those in Embodiment 1 of this application, and the permeable bricks produced in Comparative Example 1 are obtained.

[0110] Comparative Example 2

[0111] In Comparative Example 2, the drying time of the brick blank during the production of the permeable brick was not adjusted, and a fixed drying time of 10 h was maintained. The remaining steps and process parameters were exactly the same as those in Example 2 of the present application, and the permeable brick produced in Comparative Example 2 was obtained.

[0112] Comparative Example 3

[0113] In Comparative Example 3, the drying time of the brick blank during the production of the permeable brick was not adjusted, and a fixed drying time of 10 h was maintained. The remaining steps and process parameters were exactly the same as those in Example 3 of the present application, and the permeable brick produced in Comparative Example 3 was obtained.

[0114] To verify the performance of the permeable bricks produced in the present application, performance tests were carried out on the permeable bricks produced in each example and each comparative example of the present application, and the test results are shown in Table 1.

[0115] Table 1

[0116]

[0117] As can be seen from Table 1, by controlling the drying time during the drying process of the brick blank, the splitting tensile strength, flexural strength, and water permeability coefficient of the produced permeable bricks can be improved.

[0118] It should be noted that: the above-mentioned sequence of the embodiments of the present application is only for description and does not represent the superiority or inferiority of the embodiments. And the above describes specific embodiments of this specification. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0119] Each embodiment in this specification is described in a progressive manner. For the same or similar parts between each embodiment, reference can be made to each other. The key point of each embodiment is to illustrate the differences from other embodiments.

[0120] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; modifying the technical solutions recorded in the foregoing embodiments, or equivalently replacing some of the technical features, does not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of each embodiment of the present application, and should all be included within the protection scope of the present application.

Claims

1. A production and processing technology for highly water-permeable environmental protection permeable bricks, characterized in that, The process includes: Mixing the pretreated aggregate with fly ash and cement evenly to obtain a mixed solid, pouring the evenly mixed water and water reducer into the mixed solid, and stirring evenly to obtain a mixed slurry; Pressing and molding the mixed slurry and then demolding to obtain brick blanks, where the brick blanks include brick blank samples and brick blanks to be tested; Performing a drying treatment on the brick blanks, and collecting terahertz spectral data of each position and each moment during the drying treatment; Based on the similarity of the terahertz spectral data at different positions at each moment, dividing the terahertz spectral data of all positions at each moment into each clustering cluster; Using the difference in the absorption coefficients of each terahertz spectral data in each clustering cluster and the remaining terahertz spectral data, determining the absorption characteristic values of each terahertz spectral data in each clustering cluster; Based on the pore positions on the surface of the brick blank, using the absorption characteristic values to obtain a first data point set from the terahertz spectral data of all positions at each moment; Determining the first pore characteristic value at each moment according to the number of terahertz spectral data in the first data point set; Based on the position differences of different pores on the surface of the brick blank, dividing all the terahertz spectral data in the first data point set at each moment into various categories; Recording the number of the divided categories as the second pore characteristic value; Determining the proportion of each type of terahertz spectral data in the terahertz spectral data of all positions at each moment, calculating the mean value of the proportions of the terahertz spectral data of a preset number of categories at each moment, and recording it as the third pore characteristic value, and combining the first pore characteristic value to determine the pore shrinkage vector at each moment; Based on the difference between the pore shrinkage vectors at each moment and its adjacent moment, combining the first pore characteristic value, the second pore characteristic value, and the third pore characteristic value, obtaining the pore characteristic vector at each moment; Testing the splitting tensile strength and flexural strength of the brick blank samples at each moment; Using the pore characteristic vectors, splitting tensile strength, and flexural strength at each moment, and combining a multiple linear regression model to obtain a regression equation to determine the drying time for the brick blanks to be tested; Performing normal temperature curing on the brick blanks to be tested after drying treatment to obtain permeable bricks.

2. The production and processing technology of a highly water-permeable environmental protection permeable brick according to claim 1, characterized in that, The pretreatment is to put the aggregate into a crusher for crushing, screening out the aggregate part with a particle size of 5 - 10 mm, and rinsing and drying the screened aggregate.

3. The production and processing technology of a highly water-permeable environmental protection permeable brick according to claim 1, characterized in that, The mixing ratio of the cement, aggregate, fly ash, water reducer, and water is 451:1340:49:4.1:

142.

4. The production and processing technology of a highly water-permeable environmental protection permeable brick according to claim 1, characterized in that, The pressing and molding is to apply pressure at 4 - 12 MPa and hold the pressure for 30 - 80 s.

5. The production and processing technology of a highly water-permeable environmental protection permeable brick according to claim 1, characterized in that, The drying treatment includes: drying at a temperature of 75 - 105 °C, a humidity of 40% - 70%, and a ventilation speed of 0.5 - 1.5 m / s.

6. The production and processing technology of a highly water-permeable environmental protection permeable brick according to claim 1, characterized in that, The determination of the absorption characteristic value includes: Extracting the absorption coefficient spectrum of each terahertz spectral data in each clustering cluster, calculating the mean value of the amplitudes corresponding to all frequencies in the absorption coefficient spectrum, and calculating the difference between the mean value of each terahertz spectral data in each clustering cluster and the mean value of the remaining terahertz spectral data; The absorption characteristic value is the mean value of the differences of all terahertz spectral data in each clustering cluster.

7. The production and processing technology of a highly water-permeable environmental protection permeable brick according to claim 1, characterized in that, The determination of the first pore characteristic value includes: Determine the segmentation threshold of the absorption eigenvalue of the terahertz spectral data at all positions at each moment, and form a first data point set with the terahertz spectral data whose absorption eigenvalue at each moment is less than the segmentation threshold; The first eigenvalue of the pores is the proportion of the number of terahertz spectral data in the first data point set at each moment in all terahertz spectral data at each moment.

8. The production and processing technology of a highly water-permeable environmental protection permeable brick according to claim 1, characterized in that, The determination of the pore eigenvector includes: Calculate the difference between the pore shrinkage vector at each moment and its previous moment, denoted as the first difference, and form the pore eigenvector at each moment by combining the first eigenvalue of the pores, the second eigenvalue of the pores, the third eigenvalue of the pores, and the first difference.

9. The production and processing technology of a highly water-permeable environmental protection permeable brick as described in claim 1, characterized in that, The judgment of the drying time for the brick blank to be tested includes: Take the splitting tensile strength and flexural strength of the brick blank sample as the dependent variables, and the pore eigenvector of the brick blank sample as the independent variable to obtain the regression equation corresponding to the splitting tensile strength and the regression equation corresponding to the flexural strength; Input the pore eigenvector at each moment of the brick blank to be tested into each regression equation to obtain the splitting tensile strength and flexural strength at each moment of the brick blank to be tested. When both the splitting tensile strength and flexural strength of the brick blank to be tested are greater than the preset threshold, stop drying; otherwise, continue drying until the preset drying time is reached.

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