A method for determining the quality proportion of each grade based on the maximum utilization rate of cement gobi material

Abstract

The application discloses a method for determining the quality proportion of each grade based on the maximum utilization rate of cement gobi material, and belongs to the technical field of cement stabilized base. Firstly, the aggregate with a particle size greater than the maximum screen hole of a target grading is removed from the original gobi material, and the passing rate is normalized. According to the particle size from small to large, when the normalized passing rate B a of the first determined screen hole p a is not within the range of the set upper limit and the set lower limit of the passing rate, the first grade is set. The passing rate of each screen hole is corrected. According to the particle size from small to large, when the once corrected passing rate B b of the first determined screen hole p b修正1 is not within the range of the set upper limit and the set lower limit of the passing rate, the second grade is set. The passing rate of each screen hole is corrected. The grading is continued or stopped. The quality proportion of each grade is determined. The application can quickly determine the grading screen hole size with the maximum utilization rate of gobi material and the quality proportion of each grade under the condition that the specification requirements of the mixture grading are met.

Description

Technical Field

[0001] This invention relates to the field of cement-stabilized base course technology, specifically to a method for determining the quality ratio of each grade based on maximizing the utilization rate of cement Gobi material. Background Technology

[0002] With the rapid advancement of highway construction, the demand for road base materials continues to grow. Traditional base materials are limited by factors such as production location, transportation distance, and cost, making it difficult to meet the construction needs of efficient and economically controllable project progress. Therefore, developing and utilizing locally sourced materials to reduce overall project costs has become an urgent need for the industry.

[0003] Gobi aggregate, primarily produced in the Gobi Desert of southern Xinjiang, is a natural material formed from primary ore through weathering, collapse, and long-term action by wind, sand, and rain. Its main components are sand, gravel, and pebbles. Due to its abundant reserves, the "local sourcing" model significantly reduces the cost and time of transporting materials from the east or other regions, while avoiding dependence on external resources and alleviating transportation pressure. Furthermore, the unique geographical and climatic conditions of the Gobi Desert expose Gobi aggregate to extreme natural conditions over long periods, resulting in excellent strength, stability, and weather resistance. When used as a cement-stabilized base course, it better copes with local extreme weather and geological changes, improving the overall durability of the pavement structure and reducing base course cracking and deformation.

[0004] Currently, research has shown that Gobi materials can be used as road base materials, providing a technical basis for the large-scale application of Gobi materials in cement-stabilized base courses.

[0005] However, existing technologies still have the following drawbacks:

[0006] (1) On the one hand, when Gobi material with certain gradation characteristics is screened to produce crushed stone of various grades, even if the grading method is carried out in accordance with the standard requirements, it is still difficult to determine the mass ratio of each grade based on the gradation characteristics of the original Gobi aggregate, which can both meet the standard gradation requirements of the mixture and achieve the maximum utilization rate of Gobi aggregate.

[0007] (2) On the other hand, the standard grading method does not take into account the gradation characteristics of the original Gobi material, which may lead to an excessive number of gradings, resulting in complicated procedures and extended production cycles.

[0008] Based on this, the present invention designs a method for determining the mass ratio of each grade based on maximizing the utilization rate of cement Gobi material, which can be used for cement-stabilized base courses, in order to solve the above problems. Summary of the Invention

[0009] To address the aforementioned shortcomings of existing technologies, this invention provides a method for determining the mass ratio of each grade based on maximizing the utilization rate of cement Gobi material.

[0010] To achieve the above objectives, the present invention provides the following technical solution:

[0011] A method for determining the quality ratios of different grades based on maximizing the utilization rate of cement-based Gobi aggregate includes the following steps:

[0012] Step S1: Remove aggregates from the original Gobi material whose particle size is larger than the maximum sieve aperture of the target gradation, and remove aggregates whose particle size does not exceed the maximum sieve aperture of the target gradation. i The pass rate is normalized, where i represents the i-th sieve, to obtain the normalized pass rate B of the raw Gobi material in each sieve aperture. i ;

[0013] Step S2: Determine the normalized throughput B in ascending order of particle size. i Whether it is within the set upper and lower limits of the pass rate, when the sieve aperture p is first determined. a Normalized pass rate B a When the pass rate is not within the set upper and lower limits, set 0~p a Set to the first level; perform a correction on the passing rate of Gobi material at each sieve aperture, including adjusting the passing rate of Gobi material at sieve aperture p. a The pass rate is the target gradation at the sieve aperture p a Upper limit of pass rate Q a上 Or the lower limit of the pass rate Q a下 For Gobi materials with a mesh size smaller than p a The pass rate of each sieve aperture is adjusted proportionally for Gobi material at sieve aperture p. a The pass rate of each sieve aperture between the target gradation and the maximum sieve aperture is corrected by linear interpolation.

[0014] Step S3: In order of increasing particle size, sequentially determine the pass rate B after one correction for each sieve aperture above the first grade. i修正1 Whether it is within the set upper and lower limits of the pass rate, when the sieve aperture p is first determined. b The pass rate B after one correction b修正1 When the pass rate is not within the set upper and lower limits, p a ~p b Set to the second level; perform secondary correction on the passing rate of Gobi material at each sieve aperture, including adjusting the passing rate of Gobi material at sieve aperture p. b The pass rate is the target gradation at the sieve aperture p b Upper limit of pass rate Q b上 Or the lower limit of the pass rate Q b下 For Gobi materials at screen aperture p b The pass rate of each sieve aperture between the target gradation and the maximum sieve aperture is corrected by linear interpolation.

[0015] Step S4: Determine whether the passing rate of the corrected Gobi material in each sieve hole is within the range of the set upper and lower limits of the passing rate. If yes, stop the grading; if not, continue to divide the third to N grades according to the method in step S3 and correct the passing rate of the Gobi material in each sieve hole.

[0016] Step S5: Determine the quality ratio of each grade.

[0017] Furthermore, the following formula is used for normalization calculation:

[0018] B i =

[0019] Among them, X i This indicates that the raw Gobi material passed through the sieve aperture p. i quality percentage This represents the initial mass percentage of the original Gobi material at the maximum sieve aperture of the target gradation.

[0020] Furthermore, set the upper limit of throughput = target gradation at sieve aperture p. i Upper limit of pass rate Q i上 +e, set the lower limit of throughput = target gradation at sieve aperture p i Lower limit of pass rate Q i下 -e, where e is a constant.

[0021] Furthermore, a correction step is as follows:

[0022] (1) Adjust the Gobi material at the sieve aperture p a The pass rate is the target gradation at the sieve aperture p a Upper limit of pass rate Q a上 Or the target gradation is at the sieve aperture p a Lower limit of pass rate Q a下 :

[0023] If B a >Q a上 +e, then the Gobi material is within the sieve aperture p a The first correction pass rate B a修正1 =Q a上 ;

[0024] If B a <Q a下 -e, then B a修正1 =Q a下 ;

[0025] (2) Apply the following formula to the Gobi material at sieve aperture p a The following corrections were made for the throughput of each sieve aperture:

[0026] If B a >Q a上+e, B i修正1 =B i ÷B a ×Q a上 ;

[0027] If B a <Q a下 -e, B i修正1 =B i ÷B a ×Q a下 ;

[0028] (3) Apply the following formula to the Gobi material at sieve aperture p a The pass rate of each sieve aperture between the target gradation and the maximum sieve aperture is corrected:

[0029] If B a >Q a上 +e, B i修正1 =(B i -B a )÷(100-B a )×(100-Q a上 )+Q a上 ;

[0030] If B a <Q a下 -e, B i修正1 =(B i -B a )÷(100-B a )×(100-Q a下 )+Q a下 ;

[0031] B i修正1 This is the pass rate after one correction.

[0032] Furthermore, the second correction step is as follows:

[0033] (1) Adjust the Gobi material at the sieve aperture p b The pass rate is the target gradation at the sieve aperture p b Upper limit of pass rate Q b上 Or the target gradation is at the sieve aperture p b Lower limit of pass rate Q b下 :

[0034] If B b修正1 >Q b上 +e, then the Gobi material is within the sieve aperture p b The second-correction pass rate B b修正2 =Q b上 ;

[0035] If B b修正1 <Q b下 -e, then Bb修正2 =Q b下 ;

[0036] (2) Apply the following formula to the Gobi material at sieve aperture p b The throughput of each sieve aperture between the target gradation and the maximum aperture size is corrected twice:

[0037] If B b修正1 >Q b上 +e, B i修正2 =(B i -B b )÷(100-B b )×(100-Q b上 )+Q b上 ;

[0038] If B b修正1 <Q b下 -e, B i修正2 =(B i -B b )÷(100-B b )×(100-Q b下 )+Q b下 ;

[0039] B i修正2 This is the pass rate after the second correction.

[0040] Furthermore, if B b修正1 <Q b下 -e, apply the following formula to Gobi material at sieve aperture p. a The above, sieve aperture p b The following sieve aperture throughput rates are subject to secondary correction:

[0041] B i修正2 =(B i -B a )÷(B b -B a )×(Q b下 -Q a上 )+Q a上 .

[0042] Furthermore, more specifically, the method for classifying the third tier is as follows:

[0043] Based on the particle size from smallest to largest, the pass rate B after secondary correction is judged sequentially for each sieve aperture above the second grade. i修正2 Whether it is within the set upper and lower limits of the pass rate, when the sieve aperture p is first determined. c The pass rate B after the second correction c修正2 When the pass rate is not within the set upper and lower limits, p b ~p cSet it to the third level.

[0044] Furthermore, the method for adjusting the passing rate of Gobi material at each sieve aperture after classifying it into the third tier is as follows:

[0045] The pass rate of Gobi material through each sieve aperture was corrected three times:

[0046] (1) Adjust the Gobi material at the sieve aperture p c The pass rate is the target gradation at the sieve aperture p c Upper limit of pass rate Q c上 Or the target gradation is at the sieve aperture p c Lower limit of pass rate Q c下 :

[0047] If B c修正2 >Q c上 +e, then the Gobi material is within the sieve aperture p c The three-fold revised pass rate B c修正3 =Q c上 ;

[0048] If B c修正2 <Q c下 -e, then B c修正3 =Q c下 ;

[0049] (2) If B c修正2 <Q c下 -e, apply the following formula to Gobi material at sieve aperture p. b The above, sieve aperture p c The following sieve aperture throughput is corrected three times:

[0050] B i修正3 =(B i -B b )÷(B c -B b )×(Q c下 -Q b上 )+Q b上 ;

[0051] (3) Apply the following formula to the Gobi material at sieve aperture p c The pass rate of each sieve aperture between the target gradation and the maximum aperture size is corrected three times:

[0052] If B c修正2 >Q c上 +e, B i修正3 =(B i -B c )÷(100-B c )×(100-Q c上 )+Q c上 ;

[0053] If Bc修正2 <Q c下 -e, B i修正3 =(B i -B c )÷(100-B c )×(100-Q c下 )+Q c下 ;

[0054] B i修正3 This is the pass rate after three revisions.

[0055] Furthermore, i = 1 to n, where n represents the number of sieve holes.

[0056] Furthermore, set e=1.

[0057] Compared to existing technologies, the advantages of this invention are as follows: Based on the gradation characteristics of Gobi aggregate, the method of this invention can quickly determine the sieve size and mass ratio of each grade that maximizes the utilization rate of Gobi aggregate, while meeting the requirements of mixture gradation specifications, and simultaneously achieving "local material sourcing." This method effectively simplifies the number of grades, thereby reducing the number of processes. The optimized graded Gobi aggregate aggregate of this invention, when incorporated into cement, can be used to prepare cement-stabilized road base courses. Attached Figure Description

[0058] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0059] Figure 1 The results show the grading comparison between the method of this invention and the traditional grading method of CB-1 type grading.

[0060] Figure 2 The results show the grading comparison between the method of this invention and the traditional grading method of CB-3 type grading.

[0061] Figure 3 The relationship between the standard value of compressive strength and cement content of CB-1 type gradation under different mixing methods and different grading methods.

[0062] Figure 4 The relationship between the standard value of compressive strength and cement content for CB-3 type gradation under different mixing methods and different grading methods.

[0063] Figure 5The relationship between the increase in standard compressive strength of CB-1 and CB-3 gradations under different grading methods and the cement content is investigated. Detailed Implementation

[0064] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0065] Example 1: A method for determining the proportions of different grades of cement-based Gobi aggregate based on maximizing its utilization rate, comprising the following steps:

[0066] Step S1: Pre-treat the raw Gobi material;

[0067] Remove aggregates with particle sizes larger than the maximum sieve aperture of the target gradation from the original Gobi material, and normalize the passing rate of each sieve aperture not exceeding the maximum sieve aperture of the target gradation so that the normalized passing rate of the original Gobi material at the maximum sieve aperture of the target gradation is 100.0%.

[0068] Specifically, the normalization calculation is performed using the following formula:

[0069] B i =

[0070] Among them, X i This indicates that the raw Gobi material passed through the sieve aperture p. i quality percentage p represents the initial mass percentage of the original Gobi material at the maximum sieve aperture of the target gradation. i B represents the size of the i-th sieve aperture, where i = 1 to n, and n represents the number of sieve apertures. A larger i indicates a larger aperture size. i This represents the normalized throughput of the i-th sieve aperture.

[0071] Step S2: Divide the material into the first grade and adjust the passing rate of the Gobi material in each sieve opening;

[0072] Determine the normalized pass rate B in order of particle size from smallest to largest. i Is it within the range of the set upper and lower limits of the pass rate? The set upper limit of the pass rate = the target gradation at the sieve aperture p. i upper limit of pass rate Q i上 +e, set the lower limit of throughput = target gradation at sieve aperture p i Lower limit of pass rate Q i下-e, where e is a constant, for example, e=1; if so, assign i=i+1, i≤n, and continue to judge the normalized pass rate B. i Is it within the range of the set upper and lower limits of the pass rate? If not, for example, sieve aperture p a Normalized pass rate B a If the pass rate is not within the set upper and lower limits, output the sieve aperture p. a , 0~p a Set to the first level;

[0073] The pass rate of Gobi material through each sieve aperture is corrected once:

[0074] (1) Adjust the passing rate of Gobi material through sieve aperture pa to the upper limit of the passing rate Q of the target gradation through sieve aperture pa. a上 Or the target gradation has a lower limit Q of throughput at sieve aperture pA. a下 :

[0075] If B a >Q a上 +e, then the Gobi material is within the sieve aperture p a The first correction pass rate B a修正1 =Q a上 ;

[0076] If B a <Q a下 -e, then B a修正1 =Q a下 ;

[0077] (2) Apply the following formula to the Gobi material at sieve aperture p a The following corrections were made for the throughput of each sieve aperture:

[0078] If B a >Q a上 +e, B i修正1 =B i ÷B a ×Q a上 ;

[0079] If B a <Q a下 -e, B i修正1 =B i ÷B a ×Q a下 ;

[0080] (3) Apply the following formula to the Gobi material at sieve aperture p a The pass rate of each sieve aperture between the target gradation and the maximum sieve aperture is corrected:

[0081] If B a >Q a上 +e, B i修正1=(B i -B a )÷(100-B a )×(100-Q a上 )+Q a上 ;

[0082] If B a <Q a下 -e, B i修正1 =(B i -B a )÷(100-B a )×(100-Q a下 )+Q a下 ;

[0083] B i修正1 This is the pass rate after one correction;

[0084] Step S3: Divide the material into the second grade and adjust the passing rate of the Gobi material in each sieve hole;

[0085] Based on the particle size from smallest to largest, determine the pass rate B of each sieve aperture above the first grade after one correction. i修正1 Is it within the range of the set upper and lower limits of the pass rate? The set upper limit of the pass rate = the target gradation at the sieve aperture p. i Upper limit of pass rate Q i上 +e, set the lower limit of throughput = target gradation at sieve aperture p i Lower limit of pass rate Q i下 -e, where e is a constant, for example, e=1; if so, assign i=i+1, i≤n, and continue to judge the pass rate B after one correction. i修正1 Is it within the range of the set upper and lower limits of the pass rate? If not, for example, sieve aperture p b The pass rate B after one correction b修正1 If the pass rate is not within the set upper and lower limits, output the sieve aperture p. b , will p a ~p b Set to the second level;

[0086] The pass rate of Gobi material through each sieve aperture is corrected twice:

[0087] (1) Adjust the Gobi material at the sieve aperture p b The pass rate is the target gradation at the sieve aperture p b Upper limit of pass rate Q b上 Or the target gradation is at the sieve aperture p b Lower limit of pass rate Q b下 :

[0088] If B b修正1 >Q b上+e, then the Gobi material is within the sieve aperture p b The second-correction pass rate B b修正2 =Q b上 ;

[0089] If B b修正1 <Q b下 -e, then B b修正2 =Q b下 ;

[0090] (2) If B b修正1 <Q b下 -e, apply the following formula to Gobi material at sieve aperture p. a The above, sieve aperture p b The following sieve aperture throughput rates are subject to secondary correction:

[0091] B i修正2 =(B i -B a )÷(B b -B a )×(Q b下 -Q a上 )+Q a上

[0092] (3) Apply the following formula to the Gobi material at sieve aperture p b The throughput of each sieve aperture between the target gradation and the maximum aperture size is corrected twice:

[0093] If B b修正1 >Q b上 +e, B i修正2 =(B i -B b )÷(100-B b )×(100-Q b上 )+Q b上 ;

[0094] If B b修正1 <Q b下 -e, B i修正2 =(B i -B b )÷(100-B b )×(100-Q b下 )+Q b下 ;

[0095] B i修正2 This is the pass rate after secondary correction;

[0096] Step S4: Determine whether the passing rate of the corrected Gobi material in each sieve hole is within the range of the set upper and lower limits of the passing rate. If yes, stop the grading. If not, continue to divide the third to N grades according to the method in step S3 and correct the passing rate of the Gobi material in each sieve hole until the passing rate of the corrected Gobi material in each sieve hole is within the range of the set upper and lower limits of the passing rate.

[0097] Specifically, the method for classifying the Gobi material into the third tier and adjusting the passing rate of the material in each sieve aperture is as follows:

[0098] Based on the particle size from smallest to largest, determine the pass rate B after secondary correction for each sieve aperture above the second grade. i修正2 Is it within the range of the set upper and lower limits of the pass rate? The set upper limit of the pass rate = the target gradation at the sieve aperture p. i Upper limit of pass rate Q i上 +e, set the lower limit of throughput = target gradation at sieve aperture p i Lower limit of pass rate Q i下 -e, where e is a constant, for example, e=1; if so, then assign i=i+1, i≤n, and continue to judge the pass rate B after the second correction. i修正2 Is it within the range of the set upper and lower limits of the pass rate? If not, for example, sieve aperture p c The pass rate B after the second correction c修正2 If the pass rate is not within the set upper and lower limits, output the sieve aperture p. c , will p b ~p c Set to the third level;

[0099] The pass rate of Gobi material through each sieve aperture was corrected three times:

[0100] Adjust the Gobi material at the screen aperture p c The pass rate is the target gradation at the sieve aperture p c Upper limit of pass rate Q c上 Or the target gradation is at the sieve aperture p c Lower limit of pass rate Q c下 :

[0101] If B c修正2 >Q c上 +e, then the Gobi material is within the sieve aperture p c The three-fold revised pass rate B c修正3 =Q c上 ;

[0102] If B c修正2 <Q c下 -e, then B c修正3 =Q c下 ;

[0103] (2) If Bc修正2 <Q c下 -e, apply the following formula to Gobi material at sieve aperture p. b The above, sieve aperture p c The following sieve aperture throughput is corrected three times:

[0104] B i修正3 =(B i -B b )÷(B c -B b )×(Q c下 -Q b上 )+Q b上

[0105] (3) Apply the following formula to the Gobi material at sieve aperture p c The pass rate of each sieve aperture between the target gradation and the maximum aperture size is corrected three times:

[0106] If B c修正2 >Q c上 +e, B i修正3 =(B i -B c )÷(100-B c )×(100-Q c上 )+Q c上 ;

[0107] If B c修正2 <Q c下 -e, B i修正3 =(B i -B c )÷(100-B c )×(100-Q c下 )+Q c下 ;

[0108] B i修正3 This is the pass rate after three revisions.

[0109] Example 2: The target gradation is CB-1 type gradation (nominal maximum particle size 26.5mm). The Gobi aggregate is subjected to two parallel screenings using the quartering method, and the average value of the two screening results is taken as the screening result of the Gobi aggregate. The data of CB-1 type gradation given in the specification are listed in Table 1.

[0110] Table 1 Comparison of screening results for Gobi materials

[0111]

[0112] The method for determining the proportions of different quality grades based on maximizing the utilization rate of cement-based Gobi aggregate includes the following steps:

[0113] First, remove aggregates larger than 26.5mm from the original Gobi material. Then, divide the passing rate of the original Gobi material at each sieve aperture of 26.5mm and below by 92.7 to achieve normalization.

[0114] II. The normalized passing rate of Gobi material with a sieve aperture of 0.3mm is 21.5%, which is higher than the upper limit of the passing rate of CB-1 type with a sieve aperture of 0.3mm + e (e=1, 11%). Therefore, 0~0.3mm is set as the first level (lowest level). Subsequently, the passing rate of Gobi material with a sieve aperture of 0.3mm is adjusted to 10%. The passing rate of sieve apertures below 0.3mm (0.075mm, 0.15mm sieve apertures) is modified as follows: B i ÷21.5×10; The passing rate of the 0.3~26.5mm sieve aperture is modified to: (B i -21.5)÷(100-21.5)×(100-10)+10;

[0115] III. After a single correction, the pass rate of Gobi material at a 0.6mm sieve aperture is 17.8%, which is higher than the upper limit of the pass rate of the CB-1 type at a 0.6mm sieve aperture + e (e=1, 16%). Therefore, 0.3~0.6mm is set as the second grade. Subsequently, the pass rate of Gobi material at a 0.6mm sieve aperture is adjusted to 15%. The pass rate of sieve apertures above this grade (1.18~26.5mm) is modified as follows: (B i -28.3)÷(100-28.3)×(100-15)+15;

[0116] IV. After secondary correction with a sieve aperture of 13.2mm, the pass rate of Gobi material was 63%, lower than the lower limit of the pass rate of CB-1 type with a sieve aperture of 13.2mm -e (e=1, 64%). Therefore, 0.6~13.2mm was set as the third grade. Subsequently, the pass rate of Gobi material with a sieve aperture of 13.2mm was adjusted to 65%. The pass rate of sieve apertures of 1.18~9.5mm in this grade was corrected to: (B i -28.3)÷(68.8-28.3)×(65-15)+15, the calculation results are all within the upper and lower limits of the CB-1 type pass rate, the third setting is appropriate; the pass rate of sieve holes of 16mm~26.5mm above the third setting is modified to: (B i -68.8)÷(100-68.8)×(100-65)+65.

[0117] 5. The passing rates of the sieves above the third grade are all within the range of the upper and lower limits of the set passing rate, so there is no need to add additional grading between 13.2mm and 26.5mm; by summing up the above-determined grading and gradation, we can obtain the mixed material synthesis gradation that meets the CB-1 type gradation requirements, has reasonable gradation (based on the original Gobi material gradation characteristics), and maximizes the utilization rate of the original Gobi material.

[0118] VI. Based on the above method, a composite gradation that meets the CB1 type gradation requirements and maximizes the utilization rate of Gobi material can be obtained. The Gobi material is divided into four grades: 0~0.3mm, 0.3~0.6mm, 0.6~13.2mm, and 13.2~26.5mm. The mass ratio of each sieve aperture range (0~0.3mm, 0.3~0.6mm, 0.6~13.2mm, and 13.2~26.5mm) is determined to be 10:5:50:35. The calculated utilization rate of Gobi material in each grade range under the optimized gradation is shown in Table 3 below. The minimum mass ratio of original Gobi material to composite gradation in each grade range represents a Gobi material utilization rate of 75.0%.

[0119] Table 2 CB-1 Type Grading Optimization Design Table

[0120]

[0121] Table 3 Calculation results of the utilization rate of the CB-1 type gradation optimization

[0122]

[0123] Table 4 Calculation results of traditional gradation utilization rate of CB-1 type gradation

[0124]

[0125] The grading comparison results between the method of this invention and the traditional grading method of CB-1 type (see Table 4, five grades, the minimum mass ratio of original Gobi material / synthetic gradation within each grade range, i.e., the Gobi material utilization rate is 65.3%) are as follows: Figure 1 As shown in the figure, the two black solid lines represent the upper and lower limits of the CB-1 type gradation. It can be seen that compared with the traditional gradation method, the optimized gradation can not only reduce the steps to quickly design the proportion that meets the gradation requirements, but also maximize the material utilization rate and reduce the number of material gradations, thereby reducing the number of processes.

[0126] Example 3: The target gradation is CB-3 type gradation. The method of Example 1 of this invention was used for optimized grading, dividing the Gobi material into three grades: 0~0.6mm, 0.6~4.75mm, and 4.75~31.5mm. The mass ratio of each sieve aperture range (0~0.6mm, 0.6~4.75mm, 4.75~31.5mm) was then determined to be 15:17:68. The Gobi material utilization rate was 72.4%.

[0127] The comparison results between the method of this invention and the traditional grading method of CB-3 type (four grades: 0~4.75mm, 4.75~9.5mm, 9.5~19mm, and 19~31.5mm, with a mass ratio of 27.8:12.9:34.7:24.6 for each sieve aperture range of 0~4.75mm, 4.75~9.5mm, 9.5~19mm, and 19~31.5mm, and a Gobi material utilization rate of 68.2%) are as follows: Figure 2 As shown in the figure, the two black solid lines represent the upper and lower limits of the CB-3 type gradation. It can be seen that compared with the traditional grading method, the optimized grading (3 grades) method of the present invention reduces the number of grading times and improves the material utilization rate.

[0128] Example 4: The optimal moisture content at maximum dry density was determined using the heavy compaction method. The designed cement admixtures were 3.5%, 4.0%, 4.5%, and 5.0%. Standard compaction tests were conducted on the four mixtures (two gradation types, CB-3 and CB-1, each with traditional grading methods and the optimized grading method of this invention). The test results are shown in Table 5.

[0129] Table 5 Standard compaction test results

[0130]

[0131] As shown in Table 5, the difference in maximum dry density between the optimized graded mixture of the present invention and the traditional graded mixture is small, with an error of no more than 0.21%. With the increase of cement content, the optimum moisture content of the mixture increases slightly, and the maximum dry density shows a slight increasing trend. Under the same cement dosage conditions, the maximum dry density of the CB-3 graded mixture is slightly higher than that of the CB-1 graded mixture.

[0132] Example 5: The test results of the 7-day unconfined compressive strength of the mixture under various gradation methods, mixing methods, and cement dosages under two mixing methods, namely ordinary mixing and vibration mixing, are shown in Table 6.

[0133] The ordinary mixing process is as follows: first, start the ordinary mixer to preheat and dry mix for 10 seconds, then add the weighed Gobi aggregate and cement to the mixer and dry mix for 20 seconds, then add the weighed water, and wet mix for 20 seconds before stopping the machine and taking out the materials.

[0134] The vibration mixing process is as follows: First, the vibration mixer is turned on simultaneously to preheat the mixing and vibration effect for 10 seconds. Then, the weighed Gobi aggregate and cement are added to the mixer in sequence and vibrated dry for 20 seconds. Next, the weighed water is added and vibrated wet for 20 seconds before stopping the machine and removing the material.

[0135] Table 6 Results of 7d Unconfined Strength Test

[0136]

[0137] Differences in mixing method, cement dosage, gradation type, and material preparation method all affect the unconfined compressive strength of the mixture. A detailed analysis follows:

[0138] (1) The effect of cement content on strength: by Figure 3-4 As shown, the standard value of compressive strength of the mixture is positively linearly correlated with the cement content. The higher the cement content, the more hydration products that play a binding role, and the higher the compressive strength.

[0139] (2) The impact of grading method on strength: by Figure 4 As shown, when the gradation type, mixing method, and cement dosage are the same, the optimized gradation method slightly improves the compressive strength compared to the traditional gradation method. This is because the overall difference between the optimized and traditional gradations is small, with only slight differences in the 2.36~4.75mm particle size range. After optimization, the content of this particle size is slightly higher than that of the traditional gradation, and the increased proportion of fine aggregate can improve the density of the specimen, thus slightly increasing the strength. Although the improvement in compressive strength from optimized gradation is limited, it can reduce the number of material gradations and improve the utilization rate of Gobi aggregate. In engineering applications, it can reduce construction procedures, improve material utilization, and control project costs. Therefore, this method has significant practical engineering value.

[0140] (3) Effect of stirring method on standard strength value and uniformity: As shown in Table 6, the coefficient of variation of strength is significantly reduced by using vibration stirring. Figure 5 As shown, when the gradation type, sorting method, and cement content are the same, the standard strength value of the mixture produced by vibration mixing can be increased by more than 20% compared with that produced by ordinary mixing. From the mechanism of vibration mixing in improving the strength of the mixture, vibration promotes the dispersion and hydration of cement particles, while increasing the particle movement speed and the number of collisions. This is beneficial to the adhesion between cement and aggregates, enhances the bond strength between cement hydration products and aggregates, improves the strength of the mixture, and also reduces the coefficient of variation of the compressive strength of the mixture. Furthermore, as the cement content increases, the rate of strength improvement from vibration mixing gradually decreases. This is because the baseline strength of the mixture increases with the increase in cement content, and the relative potential for further strength improvement through mixing diminishes accordingly.

[0141] (4) Economic impact of vibration mixing method: Figure 4As shown, when the gradation type and grading method are the same, the standard value of compressive strength of the mixture with 4.0% cement content using vibration mixing is not lower than the standard value of compressive strength of the mixture with 5.0% cement content using ordinary mixing; the standard value of compressive strength of the mixture with 3.5% cement content using vibration mixing is not lower than the standard value of compressive strength of the mixture with 4.0% cement content using ordinary mixing. It is evident that by using vibration mixing, the amount of cement used can be reduced by at least 0.5 to 1.0 percentage points, that is, saving 12.5% ​​to 20% of cement usage. Therefore, vibration mixing, through the combined effect of "vibration + mixing," not only allows aggregate particles to be more densely packed and reduces porosity, but also has a positive impact on the economics of road base course mixture production in terms of both cost savings and strength improvement. Long-term application can significantly reduce overall costs.

[0142] (5) Effect of different gradation types on strength: As shown in Table 6, when the cement content, mixing method, and grading method are the same, the difference in the standard value of compressive strength between CB-1 type gradation and CB-3 type gradation is negligible when the cement content is 3.5%, 4.0%, and 4.5%, respectively. When the cement content is 5.0%, the standard value of compressive strength of CB-1 type gradation is slightly higher than that of CB-3 type gradation, with vibration mixing being 14.52% higher and ordinary mixing being 10.14% higher. This is because when the cement content is higher, CB-1 type gradation with more fine aggregate can make fuller use of cement hydration, ultimately achieving a strength reversal.

[0143] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for determining the mass ratio of different grades based on maximizing the utilization rate of cement-based Gobi aggregate, characterized in that, Includes the following steps: Step S1: Remove aggregates from the original Gobi material whose particle size is larger than the maximum sieve aperture of the target gradation, and remove aggregates whose particle size does not exceed the maximum sieve aperture of the target gradation. i The pass rate is normalized, where i represents the i-th sieve, to obtain the normalized pass rate B of the raw Gobi material in each sieve aperture. i ; Step S2: Determine the normalized throughput B in ascending order of particle size. i Whether it is within the set upper and lower limits of the pass rate, when the sieve aperture p is first determined. a Normalized pass rate B a When the pass rate is not within the set upper and lower limits, set 0~p a Set to the first level; perform a correction on the passing rate of Gobi material at each sieve aperture, including adjusting the passing rate of Gobi material at sieve aperture p. a The pass rate is the target gradation at sieve aperture p a upper limit of pass rate Q a上 Or the lower limit of the pass rate Q a下 For Gobi materials with a mesh size smaller than p a The pass rate of each sieve aperture is adjusted proportionally for Gobi material at sieve aperture p. a The pass rate of each sieve aperture between the target gradation and the maximum sieve aperture is corrected by linear interpolation. Step S3: In order of increasing particle size, sequentially determine the pass rate B after one correction for each sieve aperture above the first grade. i修正1 Whether it is within the set upper and lower limits of the pass rate, when the sieve aperture p is first determined. b The pass rate B after one correction b修正1 When the pass rate is not within the set upper and lower limits, p a ~p b Set to the second level; perform secondary correction on the passing rate of Gobi material at each sieve aperture, including adjusting the passing rate of Gobi material at sieve aperture p. b The pass rate is the target gradation at sieve aperture p b upper limit of pass rate Q b上 Or the lower limit of the pass rate Q b下 For Gobi materials at screen aperture p b The pass rate of each sieve aperture between the target gradation and the maximum sieve aperture is corrected by linear interpolation. Step S4: Determine whether the passing rate of the corrected Gobi material in each sieve hole is within the range of the set upper and lower limits of the passing rate. If yes, stop the grading; if not, continue to divide the third to N grades according to the method in step S3 and correct the passing rate of the Gobi material in each sieve hole. Step S5: Determine the quality ratio of each grade; One correction step is as follows: (1) Adjust the Gobi material at the sieve aperture p a The pass rate is the target gradation at sieve aperture p a upper limit of pass rate Q a上 Or the target gradation is at the sieve aperture p a Lower limit of pass rate Q a下 : If B a >Q a上 +e, then the Gobi material is within the sieve aperture p a The first correction pass rate B a修正1 =Q a上 ; If B a <Q a下 -e, then B a修正1 =Q a下 ; (2) Apply the following formula to the Gobi material at sieve aperture p a The following are corrections made for the throughput of each sieve aperture: If B a >Q a上 +e, B i修正1 =B i ÷B a ×Q a上 ; If B a <Q a下 -e, B i修正1 =B i ÷B a ×Q a下 ; (3) Apply the following formula to the Gobi material at sieve aperture p a The pass rate of each sieve aperture between the target gradation and the maximum sieve aperture is corrected: If B a >Q a上 +e, B i修正1 =(B i -B a )÷(100-B a )×(100-Q a上 )+Q a上 ; If B a <Q a下 -e, B i修正1 =(B i -B a )÷(100-B a )×(100-Q a下 )+Q a下 ; B i修正1 Let e ​​be the pass rate after one correction, and e be a constant.

2. The method for determining the mass ratio of each grade based on maximizing the utilization rate of cement Gobi material according to claim 1, characterized in that, The following formula is used for normalization calculation: B i = Among them, X i This indicates that the raw Gobi material passed through the sieve aperture p. i quality percentage This represents the initial mass percentage of the original Gobi material at the maximum sieve aperture of the target gradation.

3. The method for determining the mass ratio of each grade based on maximizing the utilization rate of cement Gobi material according to claim 1, characterized in that, Set the upper limit of throughput = target gradation at sieve aperture p i upper limit of pass rate Q i上 +e, set the lower limit of throughput = target gradation at sieve aperture p i Lower limit of pass rate Q i下 -e, where e is a constant.

4. The method for determining the mass ratio of each grade based on maximizing the utilization rate of cement Gobi material according to claim 1, characterized in that, The second correction steps are as follows: (1) Adjust the Gobi material at the sieve aperture p b The pass rate is the target gradation at sieve aperture p b upper limit of pass rate Q b上 Or the target gradation is at the sieve aperture p b Lower limit of pass rate Q b下 : If B b修正1 >Q b上 +e, then the Gobi material is within the sieve aperture p b The second-correction pass rate B b修正2 =Q b上 ; If B b修正1 <Q b下 -e, then B b修正2 =Q b下 ; (2) Apply the following formula to the Gobi material at sieve aperture p b The throughput of each sieve aperture between the target gradation and the maximum aperture size is corrected twice: If B b修正1 >Q b上 +e, B i修正2 =(B i -B b )÷(100-B b )×(100-Q b上 )+Q b上 ; If B b修正1 <Q b下 -e, B i修正2 =(B i -B b )÷(100-B b )×(100-Q b下 )+Q b下 ; B i修正2 This is the pass rate after the second correction.

5. The method for determining the mass ratio of each grade based on maximizing the utilization rate of cement Gobi material according to claim 4, characterized in that, If B b修正1 <Q b下 -e, apply the following formula to Gobi material at sieve aperture p. a The above, sieve aperture p b The following sieve aperture throughput rates are subject to secondary correction: B i修正2 =(B i -B a )÷(B b -B a )×(Q b下 -Q a上 )+Q a上 。 6. The method for determining the mass ratio of each grade based on maximizing the utilization rate of cement Gobi material according to claim 1, characterized in that, Specifically, the method for classifying the third tier is as follows: Based on the particle size from smallest to largest, the pass rate B after secondary correction is judged sequentially for each sieve aperture above the second grade. i修正2 Whether it is within the set upper and lower limits of the pass rate, when the sieve aperture p is first determined. c The pass rate B after the second correction c修正2 When the pass rate is not within the set upper and lower limits, p b ~p c Set it to the third level.

7. The method for determining the mass ratio of each grade based on maximizing the utilization rate of cement Gobi material according to claim 6, characterized in that, The method for adjusting the passing rate of Gobi material at each sieve aperture after classifying it into the third grade is as follows: The pass rate of Gobi material through each sieve aperture was corrected three times: (1) Adjust the Gobi material at the sieve aperture p c The pass rate is the target gradation at sieve aperture p c upper limit of pass rate Q c上 Or the target gradation is at the sieve aperture p c Lower limit of pass rate Q c下 : If B c修正2 >Q c上 +e, then the Gobi material is within the sieve aperture p c The three-fold revised pass rate B c修正3 =Q c上 ; If B c修正2 <Q c下 -e, then B c修正3 =Q c下 ; (2) If B c修正2 <Q c下 -e, apply the following formula to Gobi material at sieve aperture p. b The above, sieve aperture p c The following sieve aperture throughput is corrected three times: B i修正3 =(B i -B b )÷(B c -B b )×(Q c下 -Q b上 )+Q b上 ; (3) Apply the following formula to the Gobi material at sieve aperture p c The pass rate of each sieve aperture between the target gradation and the maximum aperture size is corrected three times: If B c修正2 >Q c上 +e, B i修正3 =(B i -B c )÷(100-B c )×(100-Q c上 )+Q c上 ; If B c修正2 <Q c下 -e, B i修正3 =(B i -B c )÷(100-B c )×(100-Q c下 )+Q c下 ; B i修正3 This is the pass rate after three revisions.

8. The method for determining the mass ratio of each grade based on maximizing the utilization rate of cement Gobi material according to claim 6, characterized in that, i = 1 ~ n, where n represents the number of sieve holes.

9. The method for determining the mass ratio of each grade based on maximizing the utilization rate of cement Gobi material according to claim 7, characterized in that, Set e=1.

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