Cement stabilized macadam with composite shrinkage control and preparation method thereof

Abstract

The application discloses a cement stabilized macadam for composite regulation of shrinkage, which is prepared from the following raw materials in percentage by weight: cement, water, macadam, steel slag, polyethylene glycol, superabsorbent resin and silica ash. The application also discloses a preparation method, which comprises the following steps: S1, adding the polyethylene glycol into mixing water to be stirred and dispersed into a solution, then adding the steel slag into the solution to be stirred and soaked for a certain time, so as to obtain a steel slag polyethylene glycol mixture for standby; S2, adding the superabsorbent resin into mixing water to be stirred while adding the superabsorbent resin, so as to obtain a superabsorbent resin gel for standby; S3, mixing and stirring the steel slag polyethylene glycol mixture, the superabsorbent resin gel and the macadam, adding the cement and the silica ash to be stirred, and finally adding the remaining water to be stirred, so as to obtain the cement stabilized macadam for composite regulation of shrinkage. The cement stabilized macadam can be regulated from temperature shrinkage and dry shrinkage to control the shrinkage deformation, so as to inhibit the formation and development of the shrinkage cracking of the cement stabilized macadam and improve the service performance of the road surface quality.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of road engineering, and particularly relates to a cement stabilized macadam with composite shrinkage control and a preparation method thereof. BACKGROUND

[0002] The cement stabilized macadam is the most widely used base material in China and is the main load-bearing structure layer of the asphalt pavement. The base has high bearing capacity, large rigidity, good mechanical properties, simple construction process and low cost. However, the base has poor deformation resistance, shrinks under the humidity and temperature change gradient, cracks, further deteriorates into reflection cracks, and seriously affects the service performance and durability of the pavement.

[0003] Researches show that the shrinkage of the cement stabilized macadam is mainly dry shrinkage and temperature shrinkage. The dry shrinkage mainly occurs in the initial stage after the construction of the base material. Due to the coupling effect of natural evaporation and internal hydration reaction of the mixture, the moisture of the mixture is continuously reduced, and the internal capillary pores of the cement stabilized macadam are caused to shrink in volume due to the loss of free water under the driving of capillary, adsorption, intermolecular and mineral crystallization, etc. This situation basically ends after the paving of the asphalt surface layer, and the dry shrinkage is changed into the temperature shrinkage, because the evaporation is basically blocked under the encapsulation of the tack coat, the prime coat and the asphalt surface layer, and with the passage of time, the hydration of the base material is also continuously weakened, so that the internal humidity of the base material basically remains constant. However, after the development of traffic, the base material will shrink due to the influence of the diurnal temperature difference and the annual temperature difference. In summary, the shrinkage of the cement stabilized macadam runs through the initial stage after the construction and the entire service period of the pavement, and needs to be controlled mainly from the dry shrinkage and the temperature shrinkage.

[0004] Chinese invention patent (publication number: CN109516736A) discloses a temperature shrinkage active control type cement stabilized macadam and a preparation method thereof. The invention patent controls the temperature shrinkage by using a phase change material, and the effect is good. However, the preparation process of the phase change material is relatively complex. After the phase change material is adsorbed on the diatomite carrier, it is solidified with cement, and needs to be maintained, dried, broken, and sieved, etc. The cost is high.

[0005] Chinese invention patent (publication number: CN110776282A) discloses a preparation method of a cement-based shaped phase change material. The phase change material prepared by the method has the advantages of high encapsulation rate, good stability, simple preparation process and low cost. Since no carrier of liquid phase change material is used, the cement dosage is particularly high, which can control the temperature shrinkage of the cement stabilized macadam, but the high-dose cement is easy to produce dry shrinkage.

[0006] A Chinese invention patent (publication number: CN 111925158 B) discloses a semi-rigid base pavement material with high strength and toughness and a preparation method thereof. The method adds a certain amount of elastic rubber particles to enhance the toughness and deformation resistance of the material, achieving shrinkage cracking, but easily leading to reduced strength and affecting the comprehensive mechanical properties. Moreover, the method mainly controls temperature shrinkage and does not control dry shrinkage.

[0007] A Chinese invention patent (publication number: CN 1145606556 A) discloses a pavement base material and a preparation method thereof. The invention uses modified polypropylene fibers to improve the crack resistance of the material. A Chinese invention patent (publication number: CN 112225507 B) discloses a road base material and a preparation method thereof. The base material has a low expansion rate and can realize the resource utilization of steel slag solid waste, but does not involve the crack resistance of the base material.

[0008] The existing technology mainly controls the cracking of the base material from the aspects of temperature shrinkage or dry shrinkage, or uses rubber particles and fibers. The temperature shrinkage control measures have the disadvantages of complex process flow or dry shrinkage of the phase change material carrier itself. The steel slag with low expansion rate is used to replace mineral aggregate to realize the resource utilization of solid waste, but the advantages of high porosity and low dry shrinkage of the steel slag are not scientifically and reasonably utilized. SUMMARY

[0009] The present application aims to provide a cement stabilized macadam with composite shrinkage control and a preparation method thereof, to solve the technical problems of poor deformation resistance of cement stabilized macadam base in the prior art, shrinkage during construction and use, cracking, and influence on the service performance and durability of the pavement. The cement stabilized macadam can be controlled from temperature shrinkage and dry shrinkage to inhibit the formation and development of cement stabilized macadam shrinkage cracking and improve the service performance of the pavement quality.

[0010] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0011] A cement stabilized macadam with composite shrinkage control comprises the following raw materials by weight percentage: cement 4.0-6.5%, water 4.5-7.5%, macadam 35-48%, steel slag 35-50%, polyethylene glycol 1.5-4%, superabsorbent resin 0.1-0.4%, and silica fume 0.5-1.5%.

[0012] The macadam is two-grade aggregate, and the particle size ratio is 2.36-4.75 mm: 0-2.36 mm. The mass ratio of particle size is (2.36-4.75 mm):(0-2.36 mm)=(64-76):(24-36).

[0013] The steel slag is two-grade aggregate, and the particle size ratio is 9.5-19mm:4.75-9.5mm, and the mass ratio of particle size is (9.5-19mm):(4.75-9.5mm)=(28-42):(58-72).

[0014] Further, the polyethylene glycol has a molecular weight of 400-800.

[0015] Further, the high water-absorbing resin is one or more of sodium polyacrylate, polyacrylamide and acrylic acid-acrylamide copolymer.

[0016] A preparation method of a cement-stabilized macadam with composite shrinkage control, comprising the following steps:

[0017] S1: polyethylene glycol is added into mixing water with a total mass of 1 / 5-1 / 4, and stirred and dispersed into a solution, then the steel slag is put into the solution and stirred, and soaked for 10-15min, to obtain a steel slag-polyethylene glycol mixture for standby;

[0018] S2: the high water-absorbing resin is added into mixing water with a total mass of 1 / 2-2 / 3, and stirred while adding the high water-absorbing resin, to ensure that the high water-absorbing resin is uniformly dispersed into granular form and does not agglomerate into a lump, to obtain a high water-absorbing resin gel for standby;

[0019] S3: the steel slag-polyethylene glycol mixture, the high water-absorbing resin gel and the macadam are mixed and stirred for 30-45s, then cement and silica ash are added and continue to stir for 30-45s, finally the remaining water is added and stirred for 120-150s, to obtain the cement-stabilized macadam with composite shrinkage control.

[0020] The present application has the following beneficial effects compared with the prior art:

[0021] 1. According to the shrinkage formation mechanism of the cement-stabilized macadam, the characteristics of the steel slag, the polyethylene glycol and the high water-absorbing resin are scientifically and reasonably utilized, to composite control the shrinkage cracks of the cement-stabilized macadam from the aspects of dry shrinkage and temperature shrinkage, wherein the dry shrinkage crack control aspect: the steel slag treated by silica ash has micro-volume expansion, which can significantly reduce the dry shrinkage of the cement-stabilized macadam, and the high water-absorbing resin is introduced as an internal curing material to ensure the humidity inside the cement-stabilized macadam and slow down the shrinkage cracking caused by the internal drying of the mixture; the temperature shrinkage crack control aspect: the water-soluble polyethylene glycol, the steel slag with rich surface texture, high internal porosity and high water absorption rate, and the cement are mixed, and the steel slag cement-based composite phase change material is formed after hardening, to inhibit the temperature shrinkage cracks through the temperature regulation effect of the phase change material.

[0022] 2. Compared with the traditional cement stabilized macadam material, the dry shrinkage coefficient and the temperature shrinkage coefficient of the cement stabilized macadam material are reduced by more than 33.1% and 20.2% respectively, the temperature shrinkage coefficient and the dry shrinkage coefficient are significantly reduced, the shrinkage cracking of the cement stabilized macadam material can be effectively inhibited, the dry shrinkage cracks and the temperature shrinkage cracks of the cement stabilized macadam base material can be effectively controlled, the formation and development of the cracks in the early hardening stage of the cement stabilized macadam are slowed down, and the base cracks of the asphalt pavement after service are further expanded into reflection cracks, so that the quality and the use performance of the asphalt pavement are ensured.

[0023] 3. The preparation process of the cement stabilized macadam is simple, the raw material cost is low, the cement stabilized macadam is easy to popularize and implement, and the resource utilization of the steel slag bulk industrial solid waste can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a process flow chart of a preparation method of the cement stabilized macadam with composite shrinkage regulation according to the application;

[0025] Figure 2 is a dry shrinkage coefficient column chart of the examples 1-5 and the comparative examples 1-3 according to the application;

[0026] Figure 3 is a temperature shrinkage coefficient column chart of the examples 1-5 and the comparative examples 1-3 according to the application. DETAILED DESCRIPTION

[0027] In order to make the purpose, the technical scheme and the advantages of the application more clear and obvious, the application is further described in detail below with reference to the drawings and preferred examples. However, it should be noted that many details in the description are only for the purpose of making the reader have a thorough understanding of one or more aspects of the application, and the aspects of the application can be realized without these specific details.

[0028] The cement stabilized macadam with composite shrinkage regulation comprises the following raw materials in percentage by weight: cement 4.0-6.5%, water 4.5-7.5%, macadam 35-48%, steel slag 35-50%, polyethylene glycol with a molecular weight of 400-800 1.5-4%, superabsorbent resin 0.1-0.4%, and silica ash 0.5-1.5%.

[0029] The macadam is two-grade aggregate, the particle size ratio is 2.36-4.75 mm: 0-2.36 mm, and the mass ratio of the particle size is (2.36-4.75 mm):(0-2.36 mm)=(64-76):(24-36).

[0030] The steel slag is two-grade aggregate, the particle size ratio is 9.5-19 mm: 4.75-9.5 mm, and the mass ratio of the particle size is (9.5-19 mm):(4.75-9.5 mm)=(28-42):(58-72).

[0031] The high water-absorbing resin is one or more of sodium polyacrylate, polyacrylamide, and acrylic acid-acrylamide copolymer.

[0032] As shown in Figure 1 A preparation method of the cement-stabilized macadam with composite shrinkage control, comprising the following steps:

[0033] S1: polyethylene glycol is added to the mixing water with a total mass of 1 / 5-1 / 4, stirred and dispersed into a solution, then the steel slag is put into the solution and stirred, and soaked for 10-15 min, to obtain a steel slag-polyethylene glycol mixture for standby;

[0034] S2: the high water-absorbing resin is added to the mixing water with a total mass of 1 / 2-2 / 3, stirred while adding the high water-absorbing resin, to ensure that the high water-absorbing resin is uniformly dispersed into granular form without agglomeration, to obtain a high water-absorbing resin gel for standby;

[0035] S3: the steel slag-polyethylene glycol mixture, the high water-absorbing resin gel and the macadam are mixed and stirred for 30-45 s, then the cement and silica fume are added and continue to stir for 30-45 s, finally the remaining water is added and stirred for 120-150 s, to obtain the cement-stabilized macadam with composite shrinkage control.

[0036] The following is described by more specific examples.

[0037] Example 1

[0038] A cement-stabilized macadam with composite shrinkage control, comprising the following raw materials in percentage by weight: cement 5%, water 5.9%, macadam 44%, steel slag 42%, polyethylene glycol with a molecular weight of 500 1.7%, sodium polyacrylate resin 0.2%, and silica fume 1.2%.

[0039] The macadam is two-grade aggregate, with a particle size ratio of 2.36-4.75 mm:0-2.36 mm, and a mass ratio of particle size of (2.36-4.75 mm):(0-2.36 mm)=68:32.

[0040] The steel slag is two-grade aggregate, with a particle size ratio of 9.5-19 mm:4.75-9.5 mm, and a mass ratio of particle size of (9.5-19 mm):(4.75-9.5 mm)=35:65.

[0041] A preparation method of the cement-stabilized macadam with composite shrinkage control, comprising the following steps:

[0042] S1: polyethylene glycol is added to the mixing water with a total mass of 1 / 5-1 / 4, stirred and dispersed into a solution, then the steel slag is put into the solution and stirred, and soaked for 10-15 min, to obtain a steel slag-polyethylene glycol mixture for standby;

[0043] S2: The polyacrylic acid sodium resin is added to the mixing water of 1 / 2 of the total mass of water, and the polyacrylic acid sodium resin is stirred while being added to ensure that the polyacrylic acid sodium resin is uniformly dispersed in a granular form without agglomeration, and a polyacrylic acid sodium resin gel is obtained for standby;

[0044] S3: The steel slag polyethylene glycol mixture, the polyacrylic acid sodium resin gel, and the crushed stone are mixed and stirred for 40s, and after the cement and silica fume are added, the stirring is continued for 40s, and finally the remaining water is added and stirred for 120s, to obtain the composite shrinkage control cement stabilized crushed stone.

[0045] Example 2

[0046] A composite shrinkage control cement stabilized crushed stone is made of the following raw materials in weight percentage: cement 4%, water 4.5%, crushed stone 40%, steel slag 48%, polyethylene glycol with a molecular weight of 600 1.95%, polyacrylamide resin 0.15%, and silica fume 1.4%.

[0047] The crushed stone is two-grade aggregate with a particle size ratio of 2.36-4.75mm:0-2.36mm, and a mass ratio of particle size of (2.36-4.75mm):(0-2.36mm)=64:28.

[0048] The steel slag is two-grade aggregate with a particle size ratio of 9.5-19mm:4.75-9.5mm, and a mass ratio of particle size of (9.5-19mm):(4.75-9.5mm)=28:72.

[0049] A preparation method of a composite shrinkage control cement stabilized crushed stone, comprising the following steps:

[0050] S1: The polyethylene glycol is added to the mixing water of 1 / 4 of the total mass of water to be stirred and dispersed into a solution, and then the steel slag is added to the solution and stirred for 13min to obtain a steel slag polyethylene glycol mixture for standby;

[0051] S2: The high water-absorbing resin is added to the mixing water of 1 / 2 of the total mass of water, and the polyacrylamide resin is stirred while being added to ensure that the high polyacrylamide resin is uniformly dispersed in a granular form without agglomeration, and a polyacrylamide resin gel is obtained for standby;

[0052] S3: The steel slag polyethylene glycol mixture, the high water-absorbing resin gel, and the crushed stone are mixed and stirred for 45s, and after the cement and silica fume are added, the stirring is continued for 30s, and finally the remaining water is added and stirred for 150s, to obtain the composite shrinkage control cement stabilized crushed stone.

[0053] Example 3

[0054] The cement stabilized macadam for composite regulation of shrinkage is made of the following raw materials in percentage by weight: cement 4.8%, water 5.8%, macadam 44%, steel slag 40%, polyethylene glycol with molecular weight of 800 4%, acrylic acid-acrylamide copolymer resin 0.18%, silica ash 1.22%.

[0055] The macadam is two-grade aggregate, and the particle size ratio is 2.36-4.75mm:0-2.36mm, and the mass ratio of particle size is (2.36-4.75mm):(0-2.36mm)=70:36.

[0056] The steel slag is two-grade aggregate, and the particle size ratio is 9.5-19mm:4.75-9.5mm, and the mass ratio of particle size is (9.5-19mm):(4.75-9.5mm)=30:70.

[0057] The preparation method of the cement stabilized macadam for composite regulation of shrinkage comprises the following steps:

[0058] S1: polyethylene glycol is stirred and dispersed into solution in 1 / 4 of the total water mass, and then steel slag is put into the solution and stirred and soaked for 10 minutes to obtain a steel slag polyethylene glycol mixture for standby use;

[0059] S2: high water absorption resin is added into 2 / 3 of the total water mass, and acrylic acid-acrylamide copolymer resin is added and stirred to ensure that the acrylic acid-acrylamide copolymer resin is uniformly dispersed into granular form and does not agglomerate into lumps to obtain an acrylic acid-acrylamide copolymer resin gel for standby use;

[0060] S3: the steel slag polyethylene glycol mixture, the acrylic acid-acrylamide copolymer resin gel and macadam are mixed and stirred for 30 seconds, cement and silica ash are added and stirred for another 35 seconds, the remaining water is added and stirred for 130 seconds to obtain the cement stabilized macadam for composite regulation of shrinkage.

[0061] Example 4

[0062] The cement stabilized macadam for composite regulation of shrinkage is made of the following raw materials in percentage by weight: cement 4.8%, water 5.8%, macadam 44%, steel slag 40%, polyethylene glycol with molecular weight of 800 4%, acrylic acid-acrylamide copolymer resin 0.18%, silica ash 1.22%.

[0063] The macadam is two-grade aggregate, and the particle size ratio is 2.36-4.75mm:0-2.36mm, and the mass ratio of particle size is (2.36-4.75mm):(0-2.36mm)=76:24.

[0064] The steel slag is two-grade aggregate, and the particle size ratio is 9.5-19mm:4.75-9.5mm, and the mass ratio of particle size is (9.5-19mm):(4.75-9.5mm)=42:58.

[0065] A preparation method of a cement stabilized macadam with composite shrinkage control, comprising the following steps:

[0066] S1: polyethylene glycol is added to the mixing water with a total mass of 1 / 5 to stir and disperse into a solution, then the steel slag is put into the solution to stir and soak for 15min, to obtain a steel slag polyethylene glycol mixture for standby use;

[0067] S2: superabsorbent resin is added to the mixing water with a total mass of 1 / 2 to stir, and polyacrylic acid sodium and polyacrylamide mixed resin are added to stir, to ensure that the polyacrylic acid sodium and polyacrylamide mixed resin are uniformly dispersed into granular form and do not agglomerate into lumps, to obtain a polyacrylic acid sodium and polyacrylamide mixed resin gel for standby use;

[0068] S3: the steel slag polyethylene glycol mixture, the polyacrylic acid sodium and polyacrylamide mixed resin gel and the macadam are mixed and stirred for 35s, then cement and silica ash are added to continue stirring for 45s, finally the remaining water is added to stir for 140s, to obtain the cement stabilized macadam with composite shrinkage control.

[0069] Example 5

[0070] A cement stabilized macadam with composite shrinkage control, which is made of the following raw materials in percentage by weight: cement 6.5%, water 7.5%, macadam 48%, steel slag 35%, polyethylene glycol with a molecular weight of 700 2.4%, polyacrylic acid sodium resin 0.1%, and silica ash 0.5%.

[0071] The macadam is two-grade aggregate, and the particle size ratio is 2.36-4.75mm:0-2.36mm, and the mass ratio of particle size is (2.36-4.75mm):(0-2.36mm)=72:30.

[0072] The steel slag is two-grade aggregate, and the particle size ratio is 9.5-19mm:4.75-9.5mm, and the mass ratio of particle size is (9.5-19mm):(4.75-9.5mm)=28:60.

[0073] A preparation method of a cement stabilized macadam with composite shrinkage control, comprising the following steps:

[0074] S1: polyethylene glycol is added to the mixing water with a total mass of 1 / 4 to stir and disperse into a solution, then the steel slag is put into the solution to stir and soak for 14min, to obtain a steel slag polyethylene glycol mixture for standby use;

[0075] S2: The superabsorbent resin is added to the mixing water of 2 / 3 of the total mass of water, and the superabsorbent resin is stirred while being added, to ensure that the superabsorbent resin is uniformly dispersed in the form of particles and does not agglomerate into a mass, to obtain a superabsorbent resin gel body for standby;

[0076] S3: The steel slag polyethylene glycol mixture, the superabsorbent resin gel body, and the crushed stone are mixed and stirred for 30 s, and after the cement and silica fume are added, the stirring is continued for 40 s, and finally the remaining water is added and stirred for 120 s, to obtain a cement-stabilized crushed stone with composite shrinkage control.

[0077] Comparative Example 1

[0078] The same as Example 1, except that the traditional cement-stabilized crushed stone is used, i.e., the steel slag, polyethylene glycol, superabsorbent resin, and silica fume are not added to the composition of the raw materials, and the balance is made up with crushed stone.

[0079] Comparative Example 2

[0080] The same as Example 1, except that the polyethylene glycol is not added to the composition of the raw materials of the cement-stabilized crushed stone, and the balance is made up with crushed stone.

[0081] Comparative Example 3

[0082] The same as Example 1, except that the steel slag, superabsorbent resin, and silica fume are not added to the composition of the raw materials of the cement-stabilized crushed stone, and the balance is made up with crushed stone.

[0083] 1. Shrinkage performance experiment

[0084] The cement-stabilized crushed stone materials prepared in Examples 1-5 and Comparative Examples 1-3 are tested for the dry shrinkage coefficient and the temperature shrinkage coefficient according to the provisions of T0854-2009 and T0854-2009 in the "Highway Engineering Inorganic Binder Stabilized Material Test Regulations" (JTG E51-2009), and the experimental results are shown in Table 1. Figures 2-3

[0085] From Tables 1 and 2, it can be seen that Figure 2 Figure 3

[0086] (1) The dry shrinkage coefficient and the temperature shrinkage coefficient of Examples 1-5 of the present application are reduced to different degrees compared with Comparative Examples 1-3, and by calculation, the dry shrinkage coefficients of Examples 1-3 of the present application are reduced by 33.1%, 41.6%, and 34.0% respectively compared with Comparative Example 1, and the temperature shrinkage coefficients are reduced by 24.0%, 20.2%, and 28.3% respectively, which indicates that the dry shrinkage and temperature shrinkage of the cement-stabilized crushed stone material prepared in the present application are significantly reduced compared with the traditional cement-stabilized crushed stone material.

[0087] ​​​(2) The temperature shrinkage coefficients of the embodiments 1-5 of the present application are significantly reduced compared to the comparative example 2 without adding polyethylene glycol, which indicates that the addition of polyethylene glycol in the raw materials of the present application can reduce the formation of temperature shrinkage cracks.

[0088] This is because the water-soluble polyethylene glycol is mixed with the steel slag and cement to form a steel slag cement-based composite phase change material after mixing and hardening, and the temperature regulation effect of the phase change material can inhibit the temperature shrinkage cracks.

[0089] (3) The dry shrinkage coefficients of the embodiments 1-5 of the present application are significantly reduced compared to the comparative example 3 without adding steel slag, superabsorbent and silica fume, which indicates that the addition of steel slag, superabsorbent and silica fume in the raw materials of the present application can reduce the formation of dry shrinkage cracks.

[0090] This is because the steel slag treated with silica fume has micro-volume expansion, which can significantly reduce the dry shrinkage of cement stabilized macadam, and the introduction of superabsorbent as internal curing material can ensure the humidity inside the cement stabilized macadam, thereby slowing down the shrinkage cracking caused by drying inside the mixture.

[0091] Therefore, the present application can composite regulate the shrinkage of cement stabilized macadam material from two aspects of dry shrinkage and temperature shrinkage, significantly reduce the dry shrinkage coefficient and temperature shrinkage coefficient, and inhibit the shrinkage of cement stabilized macadam material, thereby inhibiting the generation of shrinkage cracks of cement stabilized macadam material.

[0092] The above only describes the preferred embodiments of the present application, and it should be noted that those skilled in the art can make some improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A composite shrinkage-regulating cement-stabilized crushed stone, characterized in that: It is made from the following raw materials by weight percentage: cement 4.0-6.5%, water 4.5-7.5%, crushed stone 35-48%, steel slag 35-50%, polyethylene glycol 1.5-4%, superabsorbent polymer 0.1-0.4%, and silica fume 0.5-1.5%; The crushed stone is a two-grade aggregate with a particle size ratio of 2.36–4.75 mm: 0–2.36 mm, and a mass ratio of (2.36–4.75 mm): (0–2.36 mm) = (64–76): (24–36). The steel slag is a two-grade aggregate with a particle size ratio of 9.5–19 mm: 4.75–9.5 mm, and a mass ratio of (9.5–19 mm): (4.75–9.5 mm) = (28–42): (58–72). The method for preparing the composite shrinkage-controlled cement-stabilized crushed stone includes the following steps: S1: Add polyethylene glycol to 1 / 5 to 1 / 4 of the total mass of water and stir to disperse it into a solution. Then add steel slag into the solution and stir, and soak for 10 to 15 minutes to obtain a steel slag-polyethylene glycol mixture for later use. S2: Add superabsorbent resin to 1 / 2 to 2 / 3 of the total mass of water while stirring to ensure that the superabsorbent resin is evenly dispersed into granules and does not clump together, to obtain superabsorbent resin gel for later use. S3: Mix the steel slag polyethylene glycol mixture, superabsorbent resin gel and crushed stone and stir for 30-45 seconds. Add cement and silica fume and continue stirring for 30-45 seconds. Finally, add the remaining water and stir for 120-150 seconds to obtain composite shrinkage-controlled cement-stabilized crushed stone.

2. The cement-stabilized crushed stone with composite shrinkage regulation according to claim 1, characterized in that: The polyethylene glycol has a molecular weight of 400-800.

3. The cement-stabilized crushed stone with composite shrinkage regulation according to claim 1, characterized in that: The superabsorbent resin is one or more of sodium polyacrylate, polyacrylamide, and acrylic-acrylamide copolymer.

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