A method for configuring continuous-grade aggregate using interval-grade aggregate

Abstract

The present invention relates to a method for configuring continuous-grade aggregate using interval-grade aggregate, comprising: setting a target continuous-grade aggregate gradation and obtaining the target continuous-grade aggregate gradation distribution; selecting interval-grade aggregate based on the target continuous-grade aggregate gradation distribution; screening the selected interval-grade aggregate to obtain the sieve residue per sieve aperture of the interval-grade aggregate; obtaining the ratio of the assumed usage of each interval-grade aggregate based on the sieve residue per sieve aperture of the interval-grade aggregate, and completing the configuration of the target continuous-grade aggregate according to the ratio of the assumed usage of each interval-grade aggregate. The present invention can improve the accuracy and flexibility of aggregate matching.

Description

Technical Field

[0001] The present invention relates to the technical field of concrete aggregates, in particular to a method for configuring continuous-grade aggregates by utilizing interval-grade aggregates. Background Art

[0002] As the largest building material, construction sand and gravel are in high demand year-round. In recent years, the sourcing of sand and gravel aggregates has undergone significant changes. Natural sand collected from rivers has been decreasing year by year, while aggregates processed from mountain rocks, tailings, and waste rock have become increasingly available. However, due to their lower quality, the aggregate's particle composition is highly variable, requiring constant adjustments during use. Ready-mixed concrete formulated with this sand and gravel exhibits significant workability fluctuations, resulting in inconsistent quality after hardening. Consequently, concrete production must increase the margin factor to compensate for these deficiencies, resulting in significant waste. Currently, few sand and gravel processing companies adhere to construction aggregate standards, and their primary products are generally processed to a single particle size. Companies using tailings as raw material process using a continuous particle size range. However, because tailings particle size is optimized for primary ore selection, the particle size distribution is highly variable, presenting significant challenges for concrete manufacturers. To improve the comprehensive utilization of tailings, tailings raw material companies are also shifting from continuous particle size ranges to range particle size ranges.

[0003] From the perspective of aggregate production, researching and formulating standards for interval-sized aggregates will help eliminate the current difficulties faced by manufacturers of machine-made aggregates due to the production of continuous sized aggregates. According to existing standards, most aggregate gradations are continuous. To meet these standards, aggregate manufacturers must overcome many difficulties, especially since the characteristics of some rocks make it unsuitable to produce continuously sized aggregates. This presents a significant challenge for aggregate manufacturers. Even if every effort is made to produce continuously sized aggregates, the results are unsatisfactory. Therefore, the blind pursuit of continuous sized aggregates not only seriously affects the normal production of manufacturers, weakens their enthusiasm, and significantly reduces production efficiency, but also hinders the promotion and application of machine-made aggregates and the effective utilization of tailings and waste rock.

[0004] From the perspective of aggregate usage, according to general requirements for concrete preparation, the use of continuously sized aggregates easily yields high bulk density and reduces cementitious material usage. Therefore, researching and developing a method for combining interval-sized aggregates with continuously sized aggregates will improve the flexibility of concrete preparation and better meet current practical needs. This is an innovative initiative in the development of aggregate applications and provides directional guidance. It has important practical significance for improving the performance of concrete mixes and enhancing the overall quality of concrete.

[0005] However, the current standards for "Construction Sand" (GB / T 14684), "Construction Pebbles and Crushed Stone" (GB / T 14685), and "Standard for Quality and Inspection Methods of Sand and Stone for Ordinary Concrete" (JGJ 52) only regulate continuous aggregate grading and do not explicitly address the use of interval-graded or single-graded aggregates. Therefore, how to utilize interval-graded aggregates to create continuous aggregate grading has become a key issue in the application of waste rock and tailings aggregates and in improving the performance of concrete mixes. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for configuring continuous-grade aggregates using interval-grade aggregates, standardize the configuration of continuous-grade aggregates, and improve the accuracy and flexibility of aggregate matching.

[0007] To achieve the above object, the present invention provides the following solutions:

[0008] A method for configuring continuous-grade aggregate using interval-grade aggregates, comprising:

[0009] Set the target continuous aggregate gradation and obtain the target continuous aggregate gradation distribution;

[0010] Selecting interval size aggregate based on the target continuous size aggregate gradation distribution;

[0011] Screening the selected interval-sized aggregate to obtain the sieve residue of each sieve hole of the interval-sized aggregate;

[0012] Based on the sieve residue of each sieve hole of the interval size aggregate, the ratio of the assumed amount of aggregate of each interval size is obtained, and the configuration of the target continuous size aggregate is completed according to the ratio of the assumed amount of aggregate of each interval size.

[0013] Furthermore, obtaining the target continuous aggregate gradation distribution includes:

[0014] determining a maximum particle size of a target continuous-size aggregate, and obtaining a sieve-passing percentage based on the maximum particle size;

[0015] The cumulative sieve residue of each sieve hole of the target continuous particle size aggregate is obtained according to the sieve hole passing percentage, and the cumulative sieve residue of each sieve hole is subtracted successively to obtain the sub-sieve residue of each sieve hole of the target continuous particle size aggregate. The sub-sieve residue of each sieve hole is the gradation distribution of the target continuous particle size aggregate.

[0016] Furthermore, the calculation method for obtaining the sieve hole passing percentage based on the maximum particle size is:

[0017]

[0018] Where, P is the percentage of particles passing through the sieve; D is the maximum aggregate particle size; d is the sieve diameter.

[0019] Furthermore, the calculation method for obtaining the cumulative sieve residue of each sieve hole of the target continuous particle size aggregate according to the sieve hole passing percentage is:

[0020] S=1-P (2)

[0021] Where, S is the cumulative sieve residue of each sieve hole of the target continuous particle size aggregate.

[0022] Furthermore, selecting the interval-sized aggregate includes:

[0023] Based on the maximum particle size and the maximum interval average particle size of the target continuous particle size aggregate, interval particle size aggregates are continuously selected, and the maximum particle size cumulative sieve residue of the interval particle size aggregate is not less than 20%.

[0024] Furthermore, obtaining the ratio of the assumed usage of aggregates in each interval particle size includes:

[0025] Based on the sieve residue of each sieve hole of the intermediate particle size aggregate and the sieve residue of each sieve hole of the target continuous particle size aggregate, the ratio of the assumed usage of the intermediate particle size aggregate is obtained.

[0026] Furthermore, the calculation method for obtaining the ratio of the assumed usage of aggregates in each interval is:

[0027]

[0028] Where, m is the selected m-interval size aggregate; a ij ——the fractional sieve residue of aggregate of size range j on sieve hole i; x j —Amount of aggregate of grade j; b i ——The sieve residue of target continuous size aggregate on sieve hole i.

[0029] Furthermore, completing the configuration of target continuous granular aggregate according to the ratio of the assumed usage of aggregates in each interval granularity includes:

[0030] The ratio of the assumed usage of the aggregates in each interval size is normalized to obtain the proportion of the aggregates in each interval size in the target continuous size aggregate. Based on the proportion of the aggregates in each interval size in the target continuous size aggregate, the configuration of the target continuous size aggregate is completed.

[0031] The beneficial effects of the present invention are:

[0032] The present invention provides a method for configuring continuous-grade aggregates using interval-grade aggregates in a standardized manner. The method comprises the following steps: setting a target continuous-grade aggregate gradation, selecting corresponding interval-grade aggregates and screening them, calculating the fractional sieve residues of corresponding sieve holes of the target aggregates and the ratio of the assumed amounts of aggregates of each interval-grade, and obtaining a configuration ratio. In addition, the Jacobi iteration method is used in the calculation process, and the stop condition is set to 0.001. This method can scientifically and accurately configure the interval-grade aggregates into continuous-grade aggregates, thereby improving the accuracy and flexibility of aggregate matching. The method has important practical significance for the application of waste rock and tailings aggregates and the improvement of the performance of concrete mixtures. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 This is a flow chart of a method for configuring continuous-grade aggregate using interval-grade aggregate according to an embodiment of the present invention. DETAILED DESCRIPTION

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0036] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] This embodiment provides a method for configuring continuous-grade aggregate using interval-grade aggregate, such as Figure 1 As shown, including:

[0038] S1. Set the target continuous aggregate gradation;

[0039] Based on the most densely packed state of aggregate, the target continuous size aggregate gradation distribution should satisfy Fuller's formula:

[0040]

[0041] Where, P is the percentage of particles passing through the sieve; D is the maximum aggregate particle size; d is the sieve diameter.

[0042] After determining the maximum aggregate size required, the sieve residue of each sieve can be calculated:

[0043] S=1-P (2)

[0044] Where, S is the cumulative sieve residue of each sieve hole.

[0045] S is the cumulative sieve residue of each sieve hole. The positive number obtained by subtracting two adjacent numbers is the fractional sieve residue, that is, the target continuous particle size aggregate gradation distribution [S], [S] represents a set of column vectors, which is represented by b i Composition, b i It indicates the sieve residue of target continuous grade aggregate on sieve hole i.

[0046] Alternatively, the cumulative sieve residue of the target continuous-grade aggregate can be set according to the requirements for sand and gravel particle grading in the Standard Method for Testing the Quality of Sand and Stone for Ordinary Concrete JGJ 52, and the sub-sieve residue can be calculated from the cumulative sieve residue of the target aggregate, ultimately obtaining [S].

[0047] S2. Select the corresponding interval size aggregate;

[0048] The available aggregate sizes are shown in Table 1.

[0049] Table 1

[0050]

[0051] The following conditions should be met when selecting interval-sized aggregates:

[0052] ① Aggregates of varying particle sizes should be selected continuously;

[0053] ② The maximum particle size D of the target continuous granular aggregate must be max To select the maximum interval average particle size D a The value of the interval size aggregate, the D max The cumulative screen residue should not be less than 20%.

[0054] S3. The aggregate of the interval size selected in step S2 is screened, and the sum of the sieve residue of each sieve hole and the assumed amount of aggregate of each interval size multiplied by the sieve residue of the target aggregate corresponding to the sieve hole is equal to the sieve residue of the target aggregate;

[0055] After the interval size aggregate is selected, the selected aggregate sieve residue is calculated to obtain the sieve residue of each sieve hole size. The table is shown in Table 2.

[0056] Table 2

[0057]

[0058] The sum of the product of the fractional sieve residue of each sieve hole and the assumed amount of aggregate in each particle size interval should be equal to the fractional sieve residue of the corresponding sieve hole of the target aggregate:

[0059]

[0060] Where, m is the selected m-interval size aggregate; a ij ——the fractional sieve residue of aggregate of size range j on sieve hole i; x j —Amount of aggregate of grade j; b i ——The sieve residue of target continuous size aggregate on sieve hole i.

[0061] S4. Calculate the ratio of the assumed amount of aggregate in each interval and normalize the result to get the configuration ratio

[0062] The calculated value x, i.e. the ratio of the aggregate dosage in each interval, is divided by the sum of all dosages to obtain the normalized ratio of the aggregate dosage in that interval in the target aggregate.

[0063] The method proposed in this embodiment is verified as follows

[0064] (1) The requirements of JGJ 52 for sand gradation are shown in Table 3. The target continuous size aggregate gradation is determined as shown in Table 4.

[0065] Table 3

[0066]

[0067] Table 4

[0068] Sieve aperture / mm 0.15 0.30 0.60 1.18 2.36 4.75 Cumulative sieve residue / % 96 81 65 45 23 8 Sieve residue / % 15 16 20 22 15 8

[0069] (2) Continuously select the five interval size aggregates shown in Table 5 below and measure their corresponding sieve residues respectively.

[0070] Table 5

[0071] Sieve residue / % 0.15 0.3 0.6 1.18 2.36 4.75 0-0.315 88 8 0 0 0 0 0.315-1.25 14 53 23 7 0 0 0.63-2.5 0 9 58 21 6 0 1.25-5 0 0 6 62 21 3 2.5-10 0 0 0 11 53 27

[0072] (3) The sum of the product of the fractional sieve residue of each sieve hole and the assumed amount of aggregate in each particle size interval should be equal to the fractional sieve residue of the target aggregate corresponding to the sieve hole. Assuming that the amount of aggregate in the above particle size intervals is x1, x2, x3, x4, and x5 respectively, the following formula is given:

[0073] 88x1+14x2=15

[0074] 8x1+53x2+9x3=16

[0075] 23x2+58x3+6x4=20

[0076] 7x2+21x3+62x4+11x5=22

[0077] 6x3+21x4+53x5=15

[0078] 3x4+27x5=8

[0079] (4) The calculation results are: x1 = 0.1315, x2 = 0.2447, x3 = 0.2255, x4 = 0.2118, x5 = 0.1949;

[0080] The normalized results are: x1=13.0%, x2=24.3%, x3=22.4%, x4=21.0%, x5=19.3%.

[0081] During the mix, based on the desired concrete strength and water-cement ratio, the sand ratio is calculated from a table. The required fine aggregate mass M is then multiplied by x1, x2, x3, x4, and x5, respectively, to determine the required aggregate quantities for intervals 1 through 5. Aggregates from each interval are then evenly mixed to achieve the desired continuous gradation. This method allows for the scientific and accurate mixing of interval-graded aggregates into a continuous aggregate.

[0082] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for configuring continuous-size aggregate using interval-size aggregate, characterized in that: include: Set the target continuous aggregate gradation and obtain the target continuous aggregate gradation distribution; Selecting interval size aggregate based on the target continuous size aggregate gradation distribution; Screening the selected interval-sized aggregate to obtain the sieve residue of each sieve hole of the interval-sized aggregate; Based on the sieve residue of each sieve hole of the interval size aggregate, the ratio of the assumed amount of aggregate of each interval size is obtained, and the configuration of the target continuous size aggregate is completed according to the ratio of the assumed amount of aggregate of each interval size; Obtaining the ratio of the assumed amount of aggregate in each interval includes: Based on the sieve residue of each sieve hole of the intermediate size aggregate and the sieve residue of each sieve hole of the target continuous size aggregate, obtaining the ratio of the assumed amount of the intermediate size aggregate; The calculation method for obtaining the ratio of the assumed amount of aggregate in each interval is: Where, m is the selected m-interval size aggregate; a ij ——the fractional sieve residue of aggregate of size range j on sieve hole i; x j —Amount of aggregate of grade j; b i ——the sieve residue of the target continuous size aggregate on sieve hole i; The configuration of target continuous aggregate grading according to the ratio of the assumed usage of aggregate grading in each interval includes: The ratio of the assumed usage of the aggregates in each interval size is normalized to obtain the proportion of the aggregates in each interval size in the target continuous size aggregate. Based on the proportion of the aggregates in each interval size in the target continuous size aggregate, the configuration of the target continuous size aggregate is completed.

2. The method for configuring continuous-grade aggregate using interval-grade aggregate according to claim 1, characterized in that: Obtaining the target continuous aggregate gradation distribution includes: determining a maximum particle size of a target continuous-size aggregate, and obtaining a sieve-passing percentage based on the maximum particle size; The cumulative sieve residue of each sieve hole of the target continuous particle size aggregate is obtained according to the sieve hole passing percentage, and the cumulative sieve residue of each sieve hole is subtracted successively to obtain the sub-sieve residue of each sieve hole of the target continuous particle size aggregate. The sub-sieve residue of each sieve hole is the gradation distribution of the target continuous particle size aggregate.

3. The method for configuring continuous-grade aggregate using interval-grade aggregate according to claim 2, characterized in that: The calculation method for obtaining the percentage of particles passing through the sieve based on the maximum particle size is: Where, P is the percentage of particles passing through the sieve; D is the maximum aggregate particle size; d is the sieve diameter.

4. The method for configuring continuous-grade aggregate using interval-grade aggregate according to claim 3, characterized in that: The calculation method for obtaining the cumulative sieve residue of each sieve hole of the target continuous particle size aggregate according to the sieve hole passing percentage is as follows: S=1-P (2) Where, S is the cumulative sieve residue of each sieve hole of the target continuous particle size aggregate.

5. The method for configuring continuous-grade aggregate using interval-grade aggregate according to claim 1, characterized in that: The selection of the interval sized aggregate includes: Based on the maximum particle size and the maximum interval average particle size of the target continuous particle size aggregate, interval particle size aggregates are continuously selected, and the maximum particle size cumulative sieve residue of the interval particle size aggregate is not less than 20%.

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