High-temperature-resistant aerogel mortar composite recycled concrete and preparation method thereof

Abstract

The application discloses a high-temperature-resistant aerogel mortar composite recycled concrete and a preparation method thereof, which comprises the following steps: preparing a recycled concrete comprising cement, fly ash, recycled coarse aggregate, river sand, a water reducing agent and water, and preparing an aerogel mortar comprising cement, river sand, SiO2 aerogel, a KH-550 reagent, a water reducing agent and water; and combining the recycled concrete and the aerogel mortar by one-piece molding, so as to fully utilize waste material resources, reduce the dependence on natural resources, improve the high-temperature-resistant performance of the recycled concrete, and have a wide application prospect.

Description

Technical Field

[0001] This invention belongs to the field of concrete preparation technology, specifically relating to a high-temperature resistant aerogel mortar composite recycled concrete and its preparation method. Background Technology

[0002] As the cornerstone of modern construction, concrete has always been a crucial subject in engineering research, particularly regarding its various properties. Under high temperatures, the physical and chemical properties of concrete often undergo significant changes, such as reduced strength, thermal expansion, and the formation of microcracks. As ambient temperature rises, the temperature of the concrete also gradually increases from the outside in. These internal changes affect the material's fundamental properties from the inside out, ultimately leading to spalling or damage. These changes can severely impact the safety of buildings.

[0003] Currently, most research on building materials in fire scenarios focuses on directly exposing prepared samples to high-temperature equipment. However, in actual fires, fires often develop gradually from one or more ignition points, and the fire exposure of concrete structures is complex and varied, progressing from single-sided to multi-sided fire. While this method can simulate the performance changes of building materials under the most unfavorable fire scenarios, it differs significantly from real-world conditions. Therefore, testing should consider the fire exposure scenarios of the samples as much as possible, taking into account the performance changes of building materials under complex conditions. Summary of the Invention

[0004] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0005] In view of the problems existing in the above and / or prior art, the present invention is proposed.

[0006] Therefore, the purpose of this invention is to overcome the shortcomings of the prior art and provide a high-temperature resistant aerogel mortar composite recycled concrete.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: the aerogel mortar composite recycled concrete is obtained by mixing aerogel heat insulation mortar and recycled concrete;

[0008] The recycled concrete components, by mass, include 270-310 parts of ordinary Portland cement, 90-104 parts of fly ash, 610-650 parts of river sand, 925-959 parts of recycled coarse aggregate, 1.80-2.07 parts of water-reducing agent, and 160-180 parts of water.

[0009] By weight, the aerogel mortar comprises 550-578 parts of ordinary silicate cement, 321-963 parts of river sand, 27-54 parts of SiO2 aerogel, 1.95-2.15 parts of KH-550 reagent, 5.0-6.2 parts of water-reducing agent, and 230-270 parts of water.

[0010] As a preferred embodiment of the preparation method described in this invention, the recycled concrete components include 290 parts of ordinary silicate cement, 97 parts of fly ash, 635 parts of river sand, 942 parts of recycled coarse aggregate, 1.94 parts of water-reducing agent, and 170 parts of water.

[0011] By weight, the aerogel mortar comprises 564 parts of ordinary silicate cement, 643 parts of river sand, 40.5 parts of SiO2 aerogel, 2.03 parts of KH-550 reagent, 5.64 parts of water-reducing agent, and 248 parts of water.

[0012] As a preferred embodiment of the preparation method described in this invention, the aerogel mortar composite recycled concrete has the following characteristics:

[0013] (a) The compressive strength of the aerogel mortar composite recycled concrete at 20°C is 32.8-38.1 MPa;

[0014] (b) The compressive strength of the aerogel mortar composite recycled concrete at 800℃ is 28.7-32.7 MPa;

[0015] (c) The surface temperature of the inner concrete of the 800℃ aerogel mortar composite recycled concrete is 378-395℃.

[0016] (d) The mass loss rate of the aerogel mortar composite recycled concrete at 800℃ is 5.5%-6.1%. As a preferred embodiment of the preparation method described in this invention, the fineness modulus of the river sand is 2.3-2.9, and the particle size is 0.075-4.75mm.

[0017] As a preferred embodiment of the preparation method described in this invention, the water-reducing agent is a polycarboxylate water-reducing agent with a water-reducing efficiency of 20% and a dosage of 0.5% of the mass of the cementitious material.

[0018] In a preferred embodiment of the preparation method described in this invention, the recycled coarse aggregate has a particle size of 5-20 mm and an apparent density >2350 kg / m³. 3Crushing value <16%, water absorption <7%, and strength <10%.

[0019] In a preferred embodiment of the preparation method described in this invention, the mass ratio of ordinary silicate cement to fly ash is 3:1.

[0020] In a preferred embodiment of the preparation method described in this invention, the water-cement ratio of the recycled concrete is 0.41-0.47.

[0021] Another objective of this invention is to overcome the shortcomings of the prior art and provide a method for preparing high-temperature resistant aerogel mortar composite recycled concrete.

[0022] As a preferred embodiment of the preparation method described in this invention, the recycled coarse aggregate and river sand are mixed evenly, 50% water is added, cement and fly ash are added and mixed evenly, then water-reducing agent and the remaining water are added and mixed evenly to obtain the mixture.

[0023] The mixture is loaded into the mold and compacted in three layers during the pouring process. It is then placed on a vibrating table for 5-10 seconds to compact. After vibration, the recycled concrete is placed in the mold and left to stand for 1 hour before pouring mortar to obtain recycled concrete.

[0024] SiO2 aerogel was sieved to obtain SiO2 aerogel particles that could replace river sand.

[0025] Add water-reducing agent and KH-550 reagent to the total water volume, with the amounts being 1% of the mass of the cementitious material and 5% of the mass of the aerogel, respectively, and stir evenly to obtain a solution;

[0026] The material is obtained by mixing cementitious materials and sand;

[0027] Add the solution to the material, stir at low speed for 90 seconds, stir at high speed for 90 seconds, and then stir at low speed for 90 seconds. During the stirring process, slowly pour in the prepared SiO2 aerogel particles.

[0028] The prepared aerogel mortar is poured into the mortar pouring area reserved in the mold;

[0029] The sample was cast using a mold. After the recycled concrete was cast, it was left to stand for 1 hour. Then, aerogel mortar was cast into the remaining area, and the recycled concrete baffle was removed. After that, the aerogel mortar composite recycled concrete sample was placed on a vibrating table and vibrated for 10 seconds. After vibration, the sample was left to stand indoors for 24 hours. After demolding, it was moved into a standard curing room with a temperature of 20±2℃ and a relative humidity of 95%±3% for 28 days to obtain aerogel mortar composite recycled concrete.

[0030] In a preferred embodiment of the preparation method described in this invention, the fineness modulus of the SiO2 aerogel after sieving is 2.3-3.0.

[0031] The beneficial effects of this invention are:

[0032] This invention provides a high-temperature resistant aerogel mortar composite recycled concrete and its preparation method. An integrated molding process combining aerogel mortar and recycled concrete is designed. The resulting aerogel mortar composite recycled concrete exhibits good high-temperature resistance; when exposed to 800℃ for 2 hours, its compressive strength reaches over 80% of its initial compressive strength. Furthermore, tests show that the surface of the recycled concrete covered by aerogel mortar can maintain the temperature below the concrete's ultimate failure temperature of 380℃, demonstrating excellent high-temperature resistance. Simultaneously, it ensures no significant strength reduction occurs under high-temperature conditions, effectively protecting the strength of the building structure itself. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0034] Figure 1 This invention relates to an integrated molding mold for aerogel mortar composite recycled concrete. Detailed Implementation

[0035] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0036] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0037] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0038] Unless otherwise specified, all raw materials used in this invention are commercially available, among which the SiO2 aerogel has a specific surface area of ​​400-650 m². 2 / g, thermal conductivity is 0.017-0.023W / (m·K), apparent density is 90-100kg / m³ 3 The average size is 0-5 mm, and the porosity is greater than 92%.

[0039] Example 1

[0040] This embodiment provides a method for preparing aerogel mortar composite recycled concrete, specifically as follows:

[0041] The composition of the recycled coarse aggregate was 942 parts, fly ash 97 parts, river sand 1278 parts, ordinary silicate cement 854 parts, water-reducing agent 7.58 parts, KH-550 reagent 2.03 parts, SiO2 aerogel 40.5 parts, and water 418 parts.

[0042] The water-cement ratio of the recycled concrete is 0.44, and the preparation formula consists of 942 parts recycled coarse aggregate, 635 parts river sand, 290 parts ordinary silicate cement, 97 parts fly ash, 1.94 parts water-reducing agent, and 170 parts water.

[0043] The water-cement ratio of the aerogel mortar is 0.44. The preparation formula consists of 643 parts river sand, 564 parts ordinary silicate cement, 40.5 parts SiO2 aerogel, 2.03 parts KH-550 reagent, 5.64 parts water-reducing agent, and 248 parts water.

[0044] The preparation method of recycled concrete is as follows:

[0045] 1) First, put 942 parts of recycled coarse aggregate and 635 parts of river sand into a mixing container and mix well, then add 85 parts of water;

[0046] 2) Add 290 parts of cement and 97 parts of fly ash to the mixing container and mix well. Add 1.94 parts of water-reducing agent and the remaining water, and mix well to obtain the mixture.

[0047] 3) The mixture is loaded into the mold and compacted in three layers during the pouring process. It is then placed on a vibrating table for 5-10 seconds to compact. After vibration, the recycled concrete is placed in the mold and left to stand for 1 hour before pouring the mortar.

[0048] The preparation method of aerogel mortar is as follows:

[0049] 1) First, sieve the SiO2 aerogel and prepare it into fine aggregate with a fineness modulus between 2.3 and 3.0 to obtain SiO2 aerogel particles that replace river sand;

[0050] 2) Add 5.64 parts of water-reducing agent and 2.03 parts of KH-550 reagent to the total water volume of 248 parts, and stir well;

[0051] 3) Add the cementitious material and sand to the mixer and dry mix;

[0052] 4) Add the solution prepared in step 2) to the well-mixed material obtained in step 3), stir at low speed for 90 seconds, then stir at high speed for 90 seconds;

[0053] 5) Stir the slurry that was mixed evenly in step 4) again at low speed for 90 seconds. During the stirring process, slowly pour in 40.5 parts of SiO2 aerogel particles prepared in step 1).

[0054] 6) Pour the prepared aerogel mortar into the mortar pouring area reserved in the mold.

[0055] Aerogel mortar composite recycled concrete utilization such as Figure 1 The mold shown was used to pour the samples. After the recycled concrete and aerogel mortar were poured, the aerogel mortar composite recycled concrete sample was placed on a vibrating table and vibrated for 10 seconds. After vibration, the sample was left to stand indoors for 24 hours. After demolding, it was transferred to a standard curing room with a temperature of 20±2℃ and a relative humidity of 95%±3% for 28 days to obtain the composite recycled concrete. The sample was then dried in a 105℃ forced-air drying oven until constant weight, removed, and cooled to room temperature for mass testing. After the mass loss rate test and the compressive strength test, a high-temperature test or a separate compressive strength test was performed. After the high-temperature test, the sample was cooled to room temperature, and then the high-temperature mass test and compressive strength test were performed again. The mass loss rate test results and the compressive strength test results were the average of the values ​​of three identical samples.

[0056] Example 2

[0057] The difference from Example 1 lies in the formulation of the aerogel mortar composite recycled concrete, specifically:

[0058] The composition of the recycled coarse aggregate was 925 parts, fly ash 90 parts, river sand 1253 parts, ordinary silicate cement 834 parts, water-reducing agent 7.44 parts, KH-550 reagent 2.03 parts, SiO2 aerogel 40.5 parts, and water 418 parts.

[0059] The recycled concrete has a water-cement ratio of 0.47 and a preparation formula consisting of 925 parts recycled coarse aggregate, 610 parts river sand, 270 parts ordinary silicate cement, 90 parts fly ash, 1.8 parts water-reducing agent, and 170 parts water.

[0060] The water-cement ratio of the aerogel mortar is 0.44. The preparation formula consists of 643 parts river sand, 564 parts ordinary silicate cement, 40.5 parts SiO2 aerogel, 2.03 parts KH-550 reagent, 5.64 parts water-reducing agent, and 248 parts water.

[0061] The preparation method of recycled concrete is as follows:

[0062] 1) First, put 925 parts of recycled coarse aggregate and 610 parts of river sand into a mixing container and mix well, then add 85 parts of water;

[0063] 2) Add 270 parts of cement and 90 parts of fly ash to the mixing container and mix well. Add 1.8 parts of water-reducing agent and the remaining water, and mix well to obtain the mixture.

[0064] 3) The mixture is loaded into the mold and compacted in three layers during the pouring process. It is then placed on a vibrating table for 5-10 seconds to compact. After vibration, the recycled concrete is placed in the mold and left to stand for 1 hour before pouring the mortar.

[0065] The preparation and testing methods for aerogel mortar composite recycled concrete are the same as in Example 1.

[0066] Example 3

[0067] The difference from Example 1 lies in the formulation of the aerogel mortar composite recycled concrete, specifically:

[0068] The composition of the recycled coarse aggregate was 959 parts, fly ash 103.5 parts, river sand 1293 parts, ordinary silicate cement 874.5 parts, water-reducing agent 7.71 parts, KH-550 reagent 2.03 parts, SiO2 aerogel 40.5 parts, and water 418 parts.

[0069] The water-cement ratio of the recycled concrete is 0.41, and the preparation formula is 959 parts recycled coarse aggregate, 650 parts river sand, 310.5 parts ordinary Portland cement, 90 parts fly ash, 2.07 parts water-reducing agent, and 170 parts water.

[0070] The water-cement ratio of the aerogel mortar is 0.44. The preparation formula consists of 643 parts river sand, 564 parts ordinary silicate cement, 40.5 parts SiO2 aerogel, 2.03 parts KH-550 reagent, 5.64 parts water-reducing agent, and 248 parts water.

[0071] The preparation method of recycled concrete is as follows:

[0072] 1) First, put 959 parts of recycled coarse aggregate and 650 parts of river sand into a mixing container and mix well, then add 85 parts of water;

[0073] 2) Add 310.5 parts of cement and 103.5 parts of fly ash to the mixing container and mix well. Add 2.07 parts of water-reducing agent and the remaining water, and mix well to obtain the mixture.

[0074] 3) The mixture is loaded into the mold and compacted in three layers during the pouring process. It is then placed on a vibrating table for 5-10 seconds to compact. After vibration, the recycled concrete is placed in the mold and left to stand for 1 hour before pouring the mortar.

[0075] The preparation and testing methods for aerogel mortar composite recycled concrete are the same as in Example 1.

[0076] This invention refers to GB / T 50081—2019 "Standard for Test Methods of Mechanical Properties of Ordinary Concrete" to measure the mass loss rate and compressive strength of concrete;

[0077] This invention utilizes a multi-functional building materials firing furnace for high-temperature testing. The heating experiment follows the ISO 834 heating curve. After the ambient temperature of the sample reaches 800℃, the temperature is maintained at 800℃ for 2 hours. The heating equipment is then turned off, and the sample is allowed to cool naturally to room temperature. All test blocks are exposed to fire on four sides, with the top and bottom sides covered by 10cm thick insulating rock wool, and the remaining four sides exposed in the furnace. All test blocks are cured in a standard curing room for 28 days, then removed and dried in a 105℃ forced-air drying oven until constant weight. After cooling to room temperature, the samples are tested. The mass loss rate is measured before and after the high-temperature test, while the compressive strength test is performed after the mass loss rate test.

[0078] Table 1

[0079]

[0080] Comparative Example 1

[0081] The test conditions for this comparative example are the same as those for Example 1, but only recycled concrete is poured, and aerogel mortar is not poured. The test methods are the same as those for Example 1.

[0082] Comparative Example 2

[0083] The difference from Example 1 lies in the formulation of the aerogel mortar composite recycled concrete, specifically:

[0084] The composition of the recycled coarse aggregate was 942 parts, fly ash 85 parts, river sand 1278 parts, ordinary silicate cement 819 parts, water-reducing agent 7.34 parts, KH-550 reagent 2.03 parts, SiO2 aerogel 40.5 parts, and water 418 parts.

[0085] The recycled concrete has a water-cement ratio of 0.50 and is prepared by using 942 parts recycled coarse aggregate, 635 parts river sand, 255 parts ordinary silicate cement, 85 parts fly ash, 1.7 parts water-reducing agent, and 170 parts water.

[0086] The water-cement ratio of the aerogel mortar is 0.44. The preparation formula consists of 643 parts river sand, 564 parts ordinary silicate cement, 40.5 parts SiO2 aerogel, 2.03 parts KH-550 reagent, 5.64 parts water-reducing agent, and 248 parts water.

[0087] The preparation and testing methods for aerogel mortar composite recycled concrete are the same as in Example 1.

[0088] Comparative Example 3

[0089] The difference from Example 1 lies in the formulation of the aerogel mortar composite recycled concrete, specifically:

[0090] The composition of the recycled coarse aggregate was 942 parts, fly ash 85 parts, river sand 1278 parts, ordinary silicate cement 899.25 parts, water-reducing agent 7.875 parts, KH-550 reagent 2.03 parts, SiO2 aerogel 40.5 parts, and water 418 parts.

[0091] The water-cement ratio of the recycled concrete is 0.38, and the preparation formula is 942 parts recycled coarse aggregate, 635 parts river sand, 335.25 parts ordinary silicate cement, 111.75 parts fly ash, 2.235 parts water-reducing agent, and 170 parts water.

[0092] The water-cement ratio of the aerogel mortar is 0.44. The preparation formula consists of 643 parts river sand, 564 parts ordinary silicate cement, 40.5 parts SiO2 aerogel, 2.03 parts KH-550 reagent, 5.64 parts water-reducing agent, and 248 parts water.

[0093] The preparation and testing methods for aerogel mortar composite recycled concrete are the same as in Example 1.

[0094] Comparative Example 4

[0095] The difference from Example 1 lies in the formulation of the aerogel mortar composite recycled concrete, specifically:

[0096] The composition of the recycled coarse aggregate was 942 parts, fly ash 97 parts, river sand 956 parts, ordinary silicate cement 854 parts, water-reducing agent 7.58 parts, KH-550 reagent 2.7 parts, SiO2 aerogel 54 parts, and water 418 parts.

[0097] The water-cement ratio of the recycled concrete is 0.44, and the preparation formula consists of 942 parts recycled coarse aggregate, 635 parts river sand, 290 parts ordinary silicate cement, 97 parts fly ash, 1.94 parts water-reducing agent, and 170 parts water.

[0098] The water-cement ratio of the aerogel mortar is 0.44. The preparation formula is 321 parts river sand, 564 parts ordinary silicate cement, 54 parts SiO2 aerogel, 2.7 parts KH-550 reagent, 5.64 parts water-reducing agent, and 248 parts water.

[0099] The preparation and testing methods for aerogel mortar composite recycled concrete are the same as in Example 1.

[0100] Comparative Example 5

[0101] The difference from Example 1 lies in the formulation of the aerogel mortar composite recycled concrete, specifically:

[0102] The composition of the recycled coarse aggregate was 942 parts, fly ash 97 parts, river sand 1598 parts, ordinary silicate cement 854 parts, water-reducing agent 7.58 parts, KH-550 reagent 1.35 parts, SiO2 aerogel 27 parts, and water 418 parts.

[0103] The water-cement ratio of the recycled concrete is 0.44, and the preparation formula consists of 942 parts recycled coarse aggregate, 635 parts river sand, 290 parts ordinary silicate cement, 97 parts fly ash, 1.94 parts water-reducing agent, and 170 parts water.

[0104] The water-cement ratio of the aerogel mortar is 0.44. The preparation formula consists of 963 parts river sand, 564 parts ordinary silicate cement, 27 parts SiO2 aerogel, 1.35 parts KH-550 reagent, 5.64 parts water-reducing agent, and 248 parts water.

[0105] The preparation and testing methods for aerogel mortar composite recycled concrete are the same as in Example 1.

[0106] This invention refers to GB / T 50081—2019 "Standard for Test Methods of Mechanical Properties of Ordinary Concrete" to measure the mass loss rate and compressive strength of concrete;

[0107] This invention utilizes a multi-functional building materials firing furnace for high-temperature testing. The heating experiment follows the ISO 834 heating curve. After the ambient temperature of the sample reaches 800℃, the temperature is maintained at 800℃ for 2 hours. The heating equipment is then turned off, and the sample is allowed to cool naturally to room temperature. All test blocks are exposed to fire on four sides, with the top and bottom sides covered by 10cm thick insulating rock wool, and the remaining four sides exposed in the furnace. All test blocks are cured in a standard curing room for 28 days, then removed and dried in a 105℃ forced-air drying oven until constant weight. After cooling to room temperature, the samples are tested. The mass loss rate is measured before and after the high-temperature test, while the compressive strength test is performed after the mass loss rate test.

[0108] Table 2 Test results data for each group

[0109]

[0110]

[0111] Table 1 shows the test results of various properties of recycled concrete in different embodiments and comparative examples. As can be seen from the table, the best embodiment is Example 1. The compressive strength of Example 1 after high temperature did not decrease significantly, and the measured concrete surface temperature was approximately 378℃, lower than the failure temperature of concrete. The mass loss rate was also low, which is closely related to the use of volumetric SiO2 aerogel to replace 60% of the river sand in the aerogel mortar. Comparative Example 4 used volumetric replacement of 40% of the aerogel mortar. It can be seen that the surface temperature of the recycled concrete increased significantly, proving that the thermal insulation performance of the aerogel mortar at this replacement rate is not as good as that with 60% replacement. Comparative Example 5 used volumetric replacement of 80% of the aerogel mortar. It can be seen that the surface temperature of the recycled concrete increased to a certain extent, and the mortar strength at this point... The water-cement ratio is too low, resulting in insufficient bonding with recycled concrete. Consequently, the strength of the recycled concrete decreases significantly at high temperatures, demonstrating that the thermal insulation performance of aerogel mortar at this replacement rate is inferior to that at 60% replacement. Comparative Example 1 clearly shows that recycled concrete without aerogel mortar coating experiences a drastic decrease in compressive strength and mass loss under high-temperature conditions. Comparative Example 2 has a low water-cement ratio, resulting in higher initial strength, but the bonding between the aerogel mortar and recycled concrete during integral molding is insufficient, leading to a decrease in the thermal insulation performance of the aerogel mortar. The high surface temperature of the concrete during the high-temperature test exacerbates the performance degradation. Comparative Example 3 has a high water-cement ratio, resulting in lower initial strength, a more significant performance degradation, and a higher mass loss rate. In summary, Example 1 represents the optimal mix proportion for aerogel mortar composite recycled concrete. Preparing this type of composite recycled concrete and applying it in practical engineering can effectively improve the safety performance of buildings in fires.

[0112] This invention prepares a composite recycled concrete with high-temperature resistance by integrally molding aerogel mortar and recycled concrete. It has significant high-temperature resistance and can effectively utilize construction waste, thereby enhancing the application and promotion value of recycled concrete and showing broad application prospects.

[0113] It should be noted that 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 preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A high-temperature resistant aerogel mortar composite recycled concrete, characterized in that: The aerogel mortar composite recycled concrete is obtained by mixing aerogel heat insulation mortar and recycled concrete through an integral molding process. The recycled concrete components, by mass, include 290 parts ordinary Portland cement, 97 parts fly ash, 635 parts river sand, 942 parts recycled coarse aggregate, 1.94 parts water-reducing agent, and 170 parts water; the water-cement ratio of the recycled concrete is 0.

44. By weight, the aerogel insulating mortar comprises 564 parts of ordinary silicate cement, 643 parts of river sand, 40.5 parts of SiO2 aerogel, 2.03 parts of KH-550 reagent, 5.64 parts of water-reducing agent, and 248 parts of water.

2. The aerogel mortar composite recycled concrete as described in claim 1, characterized in that: The fineness modulus of the river sand is 2.3-2.9, and the particle size is 0.075-4.75 mm.

3. The aerogel mortar composite recycled concrete as described in claim 1, characterized in that: The recycled coarse aggregate has a particle size of 5-20 mm and an apparent density >2350 kg / m³. 3 Crushing value <16%, water absorption <7%, and strength <10%.

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