A method for optimizing cement-stabilized crushed stone mix ratio based on Taguchi design

Abstract

The invention relates to a method for optimizing cement-stabilized crushed stone mix ratio based on Taguchi design, which belongs to the technical field of civil engineering, and comprises the following steps: step one: performing Taguchi design; step two: performing indoor fatigue test and recording data to fill in the design appearance; step three: analyzing Taguchi design; step four: finding the most suitable cement-stabilized crushed stone mix ratio. The advantage of this method is that the cement-stabilized crushed stone mix ratio can be determined according to the design target fatigue life, and the aggregate lithology, gradation type and cement dosage in the mix ratio design process can be determined, thereby providing a new idea for accurately and quickly finding the cement-stabilized crushed stone mix ratio that best meets the requirements.

Description

Technical Field

[0001] The invention belongs to the technical field of civil engineering, and is a method for optimizing the mix ratio of cement-stabilized crushed stone by considering multiple factors that can be controlled artificially, and in particular relates to a method for simulating and designing the optimal mix ratio of cement-stabilized crushed stone by using Minitab software and Taguchi method. Background Art

[0002] In the field of civil engineering, people have been committed to optimizing the mix ratio of cement-stabilized crushed stone to improve the performance of cement-stabilized crushed stone, such as increasing strength, reducing shrinkage coefficient and temperature shrinkage coefficient, reducing the probability of occurrence of cracks, reducing the possibility of segregation, etc. In the process of optimizing the mix ratio of cement-stabilized crushed stone, designers mostly design single-factor experiments to find the optimal choice of this variable. In the case of multiple variables, more experiments can only be set up, which is time-consuming and laborious. The present invention is intended to optimize the design of the original cement-stabilized crushed stone mix ratio according to the purpose, and selectively select various variables that can be artificially controlled in the original design in a goal-driven manner, which is simple, fast and efficient than previous single-factor experiments. In addition, the present invention uses Minitab software to perform Taguchi design calculations, which can also save the cumbersome steps of drawing gradation curves in traditional experiments. Summary of the invention

[0003] This paper proposes a method for cement-stabilized crushed stone mix ratio using Taguchi design, which is applicable to various cement mix ratio designs. Aggregate lithology, gradation type, and cement dosage are used as control factors for calculation, and fatigue life under different stress levels is used as the design basis. The Taguchi method is used to find the cement-stabilized crushed stone mix ratio that best meets the expectations.

[0004] To achieve the above object, the technical solution of the present invention is:

[0005] A preferred method for cement-stabilized crushed stone mix design comprises the following steps:

[0006] Step 1: Conduct Taguchi design. Aggregate lithology, gradation type and cement dosage are used as control factors as the internal design table, different stress levels are used as noise factors and cement stabilized crushed stone at different stress levels are used as the external design table. Minitab software is used to generate the internal design table, and then the external design table header is input to prepare the conditions for indoor fatigue experiments and subsequent Taguchi design analysis.

[0007] Step 2: Conduct indoor fatigue test and record data to fill in the design outer table. Based on the design inner table, use the aggregate lithology, gradation type, and cement dosage as variables to design the mix ratio to make cement-stabilized crushed stone test specimens and conduct fatigue tests. Record the fatigue life of cement-stabilized crushed stone at different stress levels, and input the recorded data into the design outer table to provide a data basis for Taguchi design calculations.

[0008] Step 3: Analyze Taguchi design. Put the established table into Minitab software, and use the relationship between noise factors and control factors to conduct a Taguchi design analysis. The response data selects all stress levels of the design surface. The selected options are A: aggregate lithology, B: gradation type, C: cement dosage, AB, AC and BC. In the output of the analysis, find the corresponding divergence factor, adjustment factor and position factor in the signal-to-noise ratio response table and mean corresponding table of aggregate lithology, gradation type and cement dosage. Then select the best position of the control factor based on the signal-to-noise ratio main effect diagram and mean main effect diagram of aggregate lithology, gradation type and cement dosage.

[0009] Step 4: Find the most suitable cement-stabilized crushed stone mix ratio. Use Minitab software to predict the Taguchi design result function, enter the position combination of each control factor for calculation, keep the position of the divergence factor unchanged, and calculate the design result once the position factor changes. Find the combination with the mean that meets the requirements and the largest signal-to-noise ratio, which is the most suitable cement-stabilized crushed stone mix ratio.

[0010] Furthermore, in step one, the internal design table of Taguchi design is determined with aggregate lithology, gradation type and cement dosage as variables, and different stress level designs are used as the external design table header, thereby determining the mix ratio combination and experimental process of cement-stabilized crushed stone.

[0011] Furthermore, in step 2, fatigue tests at different stress levels are carried out in the laboratory according to the mix ratio combination determined in step 1, and then the fatigue life times of different mix ratio combinations are obtained and input into the design form.

[0012] Furthermore, in step 3, the Taguchi design eye-type analysis is performed according to the design table, the relationship between the signal-to-noise ratio and the mean of aggregate lithology, gradation type and cement dosage is analyzed, and the three control factors are classified to find the divergence factor and position factor. The divergence factor is a factor with a large signal-to-noise ratio, and the position factor is a factor with a large mean influence. Among them, the factor with a large mean influence but a small signal-to-noise ratio influence is the adjustment factor. Then find the best position of the divergence factor.

[0013] Furthermore, in step 4, Minitab software is used to find the optimal position of the position factor based on the selected divergence factor. The mix ratio result is calculated once for each selected position, and the mean that meets the requirements is found among several results. Then, the mix ratio combination with the largest signal-to-noise ratio is found among the screened combinations.

[0014] The beneficial effects of the present invention are:

[0015] The present invention uses three variables, namely aggregate lithology, gradation type and cement dosage, to design a cement-stabilized crushed stone mix ratio to make cement-stabilized crushed stone, then conducts fatigue life experiments under different stress levels and collects data for sorting, uses aggregate lithology, gradation type and cement dosage as control factors, and different stress levels as noise factors, and uses the Taguchi design method to design a type analysis of the fatigue life of cement-stabilized crushed stone to find the optimal mix ratio. Since Minitab software is used for calculation, the goal can be achieved by using the software to find the optimal mix ratio. Compared with the traditional method, this method uses the design target fatigue life to determine the cement-stabilized crushed stone mix ratio, and can simultaneously determine the three variable factors of aggregate lithology, gradation type and cement dosage in the mix ratio design process, thereby providing a new idea for accurately and quickly finding the cement-stabilized crushed stone mix ratio that best meets the requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the implementation cases of the present invention or the technical solutions in the prior art, the drawings required for use in the implementation cases or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some implementation cases of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0017] Figure 1 A Taguchi design drawing for creating a cement-stabilized crushed stone mix ratio optimization method based on Taguchi design of the present invention;

[0018] Figure 2 The invention provides a method for optimizing cement-stabilized crushed stone mix ratio based on Taguchi design to create Taguchi design level and factor design diagram;

[0019] Figure 3 It is a design option interface diagram in Taguchi design for creating a cement stabilized crushed stone mix ratio optimization method based on Taguchi design of the present invention;

[0020] Figure 4 It is a factor option interface diagram of creating a Taguchi design for the cement stabilized crushed stone mix ratio optimization method based on Taguchi design of the present invention;

[0021] Figure 5 It is an interface diagram for selecting interactively available items in the factor options of the cement stabilized crushed stone mix ratio optimization method based on Taguchi design of the present invention;

[0022] Figure 6 The design table when the Taguchi design is completed is created for the cement stabilized crushed stone mix ratio optimization method based on the Taguchi design of the present invention;

[0023] Figure 7It is the analysis Taguchi design diagram of the cement stabilized crushed stone mix ratio optimization method based on Taguchi design of the present invention;

[0024] Figure 8 It is an analysis Taguchi design interface diagram of the cement stabilized crushed stone mix ratio optimization method based on Taguchi design of the present invention;

[0025] Fig. 9 It is a graphical interface diagram of the analysis of the cement stabilized crushed stone mix ratio optimization method based on Taguchi design of the present invention;

[0026] Fig.10 It is an analysis interface diagram in Taguchi design for analyzing the cement stabilized crushed stone mix ratio optimization method based on Taguchi design of the present invention;

[0027] Fig.11 It is an interface diagram of the Taguchi design in the analysis of the cement stabilized crushed stone mix ratio optimization method based on the Taguchi design of the present invention;

[0028] Fig.12 It is an analysis of the cement stabilized crushed stone mix ratio optimization method based on Taguchi design of the present invention and an option interface diagram in Taguchi design;

[0029] Fig.13 It is a main effect diagram of the signal-to-noise ratio of the cement-stabilized crushed stone mix ratio optimization method based on Taguchi design of the present invention;

[0030] Fig.14 It is the mean main effect diagram of the cement stabilized crushed stone mix ratio optimization method based on Taguchi design of the present invention;

[0031] Fig.15 It is a predicted Taguchi result diagram of the cement stabilized crushed stone mix ratio optimization method based on Taguchi design of the present invention;

[0032] Fig.16 It is a predicted Taguchi result interface diagram of the cement stabilized crushed stone mix ratio optimization method based on Taguchi design of the present invention;

[0033] Fig.17 It is an interface diagram of the predicted Taguchi results of the cement stabilized crushed stone mix ratio optimization method based on Taguchi design of the present invention;

[0034] Fig.18 It is a horizontal interface (limestone) diagram in the predicted Taguchi results of the cement stabilized crushed stone mix ratio optimization method based on Taguchi design of the present invention;

[0035] Fig.19 It is a diagram of the horizontal interface (sandstone) in the predicted Taguchi results of the cement-stabilized crushed stone mix ratio optimization method based on Taguchi design of the present invention. DETAILED DESCRIPTION

[0036] The preferred mix ratio of cement-stabilized crushed stone is further described below based on the Taguchi method according to the present invention.

[0037] First, conduct a Taguchi design. Select the Create Taguchi Design option in Taguchi Design, refer to Figure 1 .

[0038] The design type is 2-level design, because the word count is 3, refer to Figure 2 .

[0039] Select L8 in the design options, refer to Figure 3 .

[0040] Select the factor option to allow interaction, and enter the aggregate lithology, gradation type, and cement dosage in the data as control factors. Figure 4 Click the interaction option to select the factors that can interact. Select AB, AC, BC as the option. Figure 5 .

[0041] The set design internal table is shown in Table 1.

[0042] Table 1 Design internal table

[0043] Aggregate lithology Gradation type Cement dosage Limestone Suspended dense type 3％ Limestone Suspended dense type 4％ sandstone Dense skeleton 3％ sandstone Dense skeleton 4％ Limestone Dense skeleton 3％ Limestone Dense skeleton 4％ sandstone Suspended dense type 3％ sandstone Suspended dense type 4％

[0044] Use different levels of stress as noise factors and fill in the design appearance header, refer to Figure 6 , and the fatigue life times under different stress levels are combined as the design surface. This design aims to find the cement stabilized crushed stone mix ratio with a fatigue life time greater than 85,000.

[0045] Secondly, conduct indoor fatigue tests and record the data to fill in the design surface. This design has a total of 8 mix ratio combinations. After making 8 types of cement-stabilized crushed stone, indoor fatigue life tests were carried out at different stress levels. After the experimental data was sorted out, fill it in the design surface. The design table composed of the design internal table and the design external table is shown in Table 2.

[0046] Table 2 Design table

[0047]

[0048]

[0049] Then, analyze the Taguchi design. Select Analyze Taguchi Design in Taguchi Design, refer to Figure 7 .

[0050] Response data selects all stress levels of the design surface, refer to Figure 8 .

[0051] Select the signal-to-noise ratio and mean for the main effect plots and interaction effect plots generated in the graphics options, refer to Fig. 9 .

[0052] The response table is displayed in the analysis interface. The mean and response table are also selected for the fitted linear model. Fig.10 .

[0053] The options selected in the item interface are A: aggregate lithology, B: gradation type, C: cement dosage, AB, AC and BC, refer to Fig.11 .

[0054] This analysis is based on the mesh type to analyze cement stabilized crushed stone, so choose the mesh type in the options, refer to Fig.12 .

[0055] Using the output signal-to-noise ratio effect table (Table 3) and mean effect table (Table 4) of aggregate lithology, gradation type and cement dosage, corresponding to the signal-to-noise ratio main effect diagram, refer to Fig.13 , and mean main effect plots, refer to Fig.14 , find out the divergence factor, location factor and adjustment factor for the result calculation of Taguchi design. The divergence factor is the factor with large signal-to-noise ratio, the location factor is the factor with large mean influence, and the factor with large mean influence but small signal-to-noise ratio influence is the adjustment factor. Then determine the best position of the divergence factor.

[0056] Table 3 Signal-to-noise ratio response table

[0057] level Aggregate lithology Gradation type Cement dosage 1 -5.218 -5.286 -5.559 2 -5.170 -5.103 -4.829 Delta 0.048 0.183 0.731 Ranking 3 2 1

[0058] Table 4 Mean response table

[0059] level Aggregate lithology Gradation type Cement dosage 1 69560 63644 56789 2 67714 73630 80485 Delta 1846 9986 23696 Ranking 3 2 1

[0060] Finally, determine the mix ratio of cement-stabilized crushed stone. Predict the position of the corresponding image of the divergence factor with large signal-to-noise ratio and the factor with large influence on both mean and signal-to-noise ratio. Select the gradation type and cement dosage according to the sorting in the table. The corresponding figure shows that the fatigue resistance of the cement-stabilized crushed stone designed by selecting the dense skeleton type and 4% cement dosage will be better.

[0061] After selecting the control factor position, select the predicted Taguchi result in Minitab software, refer to Fig.15 .

[0062] In the Predict Taguchi Design Results window, select Predict Mean and Signal-to-Noise Ratio, refer to Fig.16 .

[0063] The selected items in the item interface are A: aggregate lithology, B: gradation type, C: cement dosage, AB, AC and BC, refer to Fig.17 .

[0064] Enter the selected control factors in the level. The first input aggregate lithology is limestone, gradation type is skeleton dense type, cement dosage is 4%, refer to Fig.18 , and then output the calculation results (Table 5);

[0065] Table 5 Taguchi design result prediction (limestone)

[0066] Signal-to-Noise Ratio Mean -4.91551 88763.9

[0067] The second input aggregate lithology is sandstone, the gradation type is skeleton dense type, and the cement dosage is 4%. Fig.19 , and then output the calculation results (Table 6).

[0068] Table 6 Taguchi design result prediction (sandstone)

[0069] Signal-to-Noise Ratio Mean -4.80410 83464.3

[0070] Comparison of the two calculation results shows that the average number of fatigue life predicted in the first prediction is 88763.9, and the second prediction is 83464.3. The design target of fatigue life is 85000, so the first design combination can meet the standard. Since only one combination meets the standard, there is no need to compare the signal-to-noise ratio. Therefore, it can be concluded that the fatigue resistance of cement-stabilized aggregate designed with limestone is better than that of cement-stabilized crushed stone designed with sandstone.

[0071] In summary, the optimization method of cement-stabilized crushed stone mix ratio using the Taguchi method is feasible. This method can be used to further identify cement-stabilized crushed stone with good fatigue resistance by simultaneously analyzing the influencing factors that can be artificially controlled, such as aggregate lithology, aggregate type, and cement dosage, based on the original experimental data, which can improve the experimental efficiency to a certain extent.

[0072] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for optimizing cement-stabilized crushed stone mix ratio based on Taguchi design, comprising the following steps: Step 1: Conduct Taguchi design: use aggregate lithology, gradation type and cement dosage as control factors as the design inner table, different stress levels as noise factors and cement stabilized crushed stone at different stress levels as the design outer table, use Minitab software to generate the design inner table, and then input the design outer table header to prepare the conditions for indoor fatigue test and subsequent Taguchi design analysis; Step 2: Conduct indoor fatigue test and record data to fill in the design outer table: Based on the design inner table, use the aggregate lithology, gradation type, and cement dosage as variables to design the mix ratio to make cement-stabilized crushed stone test specimens, conduct fatigue tests, and record the fatigue life of cement-stabilized crushed stone at different stress levels. Enter the recorded data into the design outer table to provide a data basis for Taguchi design calculations; Step 3: Analyze Taguchi design: Put the established table into Minitab software, and use the relationship between noise factor and control factor to conduct the eye-type analysis of Taguchi design. The response data selects all stress levels of the design surface. The selected options are A: aggregate lithology, B: gradation type, C: cement dosage, AB, AC and BC. Find the corresponding divergence factor, adjustment factor and position factor in the output signal-to-noise ratio response table and mean corresponding table of aggregate lithology, gradation type and cement dosage. Then select the best position of the divergence factor according to the signal-to-noise ratio main effect diagram and mean main effect diagram of aggregate lithology, gradation type and cement dosage. Step 4: Find the most suitable cement-stabilized crushed stone mix ratio: Use Minitab software to predict the Taguchi design result function, enter the position combination of each control factor for calculation, the position of the divergence factor remains unchanged, and the design result is calculated once the position factor is changed. Find the combination with the mean that meets the requirements and the largest signal-to-noise ratio, which is the most suitable cement-stabilized crushed stone mix ratio; In the step 1, the internal design table of Taguchi design is determined with aggregate lithology, gradation type and cement dosage as variables, and different stress level designs are used as external design table headers, thereby determining the mix ratio combination and experimental process of cement-stabilized crushed stone.

2. The method for optimizing cement-stabilized crushed stone mix ratio based on Taguchi design according to claim 1, characterized in that: In the step 2, fatigue tests at different stress levels are carried out in the laboratory according to the mix ratio combination determined in the step 1, and then the fatigue life times of different mix ratio combinations are obtained and input into the design form.

3. The method for optimizing cement-stabilized crushed stone mix ratio based on Taguchi design according to claim 2, characterized in that: In the step three, a Taguchi design eye-type analysis is performed according to the design table to analyze the relationship between the signal-to-noise ratio and the mean of aggregate lithology, grading type and cement dosage, and the three control factors are classified to find the divergence factor and the position factor. The divergence factor is a factor with a large signal-to-noise ratio, and the position factor is a factor with a large influence on the mean. Among them, the factor with a large influence on the mean but a small influence on the signal-to-noise ratio is an adjustment factor, and then the optimal position of the divergence factor is found.

4. The method for optimizing cement-stabilized crushed stone mix ratio based on Taguchi design according to claim 3, characterized in that: In the step 4, Minitab software is used to find the best position of the position factor based on the selected divergence factor, and the mix ratio result is calculated once for each selected position, and the mean value that meets the requirements is found among several results, and then the mix ratio combination with the largest signal-to-noise ratio is found among the screened combinations.

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