Ceramsite lightweight aggregate structural concrete and preparation method thereof

Abstract

The invention discloses ceramsite lightweight aggregate structural concrete and a preparation method thereof, and belongs to the technical field of concrete. The ceramsite lightweight aggregate structural concrete is prepared from the following raw materials in parts by mass: 240 to 270 parts of cement, 25 to 35 parts of mineral powder, 80 to 95 parts of fly ash, 210 to 250 parts of coal gangue crushed materials, 725 to 805 parts of modified coal gangue ceramsite, 10 to 30 parts of waste rubber materials, 3.5 to 5 parts of water reducing agents and 165 to 180 parts of water. The modified coal gangue ceramsite is obtained by coating the surface of a coal gangue ceramsite matrix with an epoxy resin layer and then grafting a hydrophilic polymer, the porosity of the coal gangue ceramsite matrix is 40-60%, and the aperture ratio is 1.5-6%. The epoxy resin layer on the surface of the modified coal gangue ceramsite provides an anti-permeability barrier, the hydrophilic polymer on the surface adjusts the wettability of the ceramsite, the binding force with other components of the concrete is improved, and the concrete has excellent shrinkage and dry crack resistance.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of concrete, and particularly relates to a ceramsite lightweight aggregate structure concrete and a preparation method thereof. BACKGROUND

[0002] Lightweight aggregate concrete, also known as lightweight concrete, has the characteristics of light weight, high strength, good heat preservation and insulation performance, and good seismic resistance, and is widely used in civil engineering.

[0003] Lightweight aggregate is an important component of lightweight aggregate concrete, and plays a role of skeleton support in lightweight aggregate concrete. The performance and characteristics of lightweight aggregate determine the performance and characteristics of lightweight aggregate concrete. The lightweight aggregate concrete prepared by taking coal gangue ceramsite as aggregate not only can utilize coal gangue in large quantities and improve the comprehensive utilization rate of coal gangue, but also can greatly reduce the consumption of natural aggregate in civil engineering, and has important significance for realizing large-scale utilization of coal gangue resources and development of green building materials.

[0004] However, due to the porosity of the ceramsite, the water absorption rate is high, the shrinkage rate of the ceramsite lightweight aggregate concrete is large, and the ceramsite lightweight aggregate concrete is prone to cracking, which affects the service life. In order to ensure the mechanical properties of the concrete, pre-wetting treatment is required before construction, which increases the complexity of construction. Therefore, reducing the water absorption rate of the ceramsite lightweight aggregate has important significance for preventing the concrete from cracking and enhancing the durability. SUMMARY

[0005] The application provides a ceramsite lightweight aggregate structure concrete and a preparation method thereof, and can solve the problem that the ceramsite lightweight aggregate concrete is prone to shrinkage and cracking in the prior art.

[0006] The purpose of the application can be achieved by the following technical solutions. A ceramsite lightweight aggregate structure concrete, which comprises the following raw materials in parts by mass: cement 240-270 parts, mineral powder 25-35 parts, fly ash 80-95 parts, coal gangue crushed material 210-250 parts, modified coal gangue ceramsite 725-805 parts, waste rubber material 10-30 parts, water reducing agent 3.5-5 parts, and water 165-180 parts; The modified coal gangue ceramsite is obtained by coating an epoxy resin layer on the surface of a coal gangue ceramsite base body and then grafting a hydrophilic polymer. The porosity of the coal gangue ceramsite base body is 40-60%, and the open porosity is 1.5-6%.

[0007] The modified coal gangue ceramsite with high porosity and low open porosity is used as the aggregate, which can ensure the lightweight property of the concrete, reduce the water absorption of the ceramsite, avoid the shrinkage and cracking of the concrete, and prolong the service life. The waste rubber material is synchronously added, which can realize the waste utilization and improve the elasticity, stress buffering, crack resistance and frost resistance of the concrete. The density of the rubber material is relatively small, and the concrete bulk density can be reduced by replacing part of the mineral material. The durability of the concrete is improved by the modification of the ceramsite absorption and the improvement of the matrix toughness.

[0008] Further, the modified coal gangue ceramsite includes small particle size modified coal gangue ceramsite, medium particle size modified coal gangue ceramsite and large particle size modified coal gangue ceramsite. The particle size of the small particle size modified coal gangue ceramsite is <3mm. The particle size of the medium particle size modified coal gangue ceramsite is 3-8mm. The particle size of the large particle size modified coal gangue ceramsite is 13-15mm.

[0009] Further, the mass ratio of the small particle size modified coal gangue ceramsite, the medium particle size modified coal gangue ceramsite and the large particle size modified coal gangue ceramsite is (235-255):(280-320):(210-230).

[0010] The three-level particle size ceramsite is used to improve the workability and strength of the concrete.

[0011] Further, the coal gangue ceramsite matrix includes the following raw materials in terms of mass fraction: Coal gangue 50-70 parts, silicon carbide 10-25 parts, borax 4-8 parts, volcanic ash 15-20 parts, sodium carbonate 3-7 parts, waste glass powder 8-12 parts, and starch 7-13 parts.

[0012] The conventional coal gangue ceramsite will form through pores due to thermal decomposition during the sintering process, and such pores are the main channels for water absorption of the ceramsite. The starch is added as a pore former in the raw materials of the coal gangue ceramsite, and the starch is rapidly decomposed to form pores in the early sintering stage due to its low decomposition temperature. At this time, the pore structure is mainly open pores. The sodium carbonate and borax are used as solubilizers to reduce the eutectic temperature of the mixture, and a liquid phase is formed in the sintered material to block the pores and convert the open pores into closed pores. Through the synergistic effect of multiple components in the coal gangue ceramsite, the ceramsite with high porosity and low open porosity structure is formed.

[0013] Further, the preparation steps of the modified coal gangue ceramsite are as follows: S1, prepare the raw materials of the coal gangue ceramsite matrix according to the proportion, mix the raw materials in the mixer to form green balls by adding water, and S2, the raw material ball is preheated at 400-600℃ for 0.5-1h, then heated to 1100-1250℃ for sintering, and the temperature is kept for 20-30min; S3, after sintering, the coal gangue ceramic granule matrix is obtained by natural cooling to room temperature; S4, the coal gangue ceramic granule matrix is immersed in the amino silane coupling agent hydrolysis solution, and is placed for 10-20min, and is taken out and dried; S5, the epoxy resin and the curing agent are dissolved in acetone to form an epoxy resin solution, the ceramic granule after drying in S4 is added into the epoxy resin solution, and is immersed and coated for 5-10min, and is taken out and heated to form an epoxy resin coating; S6, the hydrophilic monomer is dissolved in water to form a mixed solution, and an initiator is added; the ceramic granule after curing in S5 is immersed in the mixed solution, and is heated to react for 4-6h under nitrogen protection, the surface of the epoxy resin coating is modified to be hydrophilic, and the modified coal gangue ceramic granule is obtained by taking out and drying.

[0014] Generally, the water absorption of the coal gangue ceramic granule is mainly due to the capillary action of the pores, and the surface of the ceramic granule is often modified to be hydrophobic in the prior art to reduce the water absorption rate, but this method has certain limitations, the surface hydrophobic modification has weak resistance to the capillary water absorption of the pores, and the actual improvement effect needs to be improved. The coal gangue ceramic granule is first immersed and grafted with the amino silane coupling agent, then the amino group of the amino silane coupling agent reacts with the epoxy group of the epoxy resin, the epoxy resin is crosslinked and solidified on the surface of the ceramic granule, the surface of the ceramic granule is covered with a dense epoxy resin film, the surface pores are sealed, and the water absorption rate of the ceramic granule is greatly reduced. However, since the epoxy resin has poor hydrophilicity, the ceramic granule has poor wettability and weak bonding force with other components when directly used in concrete, and it is difficult to achieve uniform mixing. The ceramic granule with the sealed pores is further grafted with a hydrophilic polymer to improve the hydrophilicity of the surface of the ceramic granule. Through the modification treatment of the coal gangue ceramic granule, the uniform dispersion and wettability of the ceramic granule in the concrete can be ensured, and the water absorption rate of the ceramic granule can be reduced.

[0015] Further, in S1, the mass of the mixture and water is 100:8-15.

[0016] Further, the amino silane coupling agent hydrolysis solution is obtained by hydrolyzing the amino silane coupling agent in an alcohol aqueous solution. The amino silane coupling agent is gamma-aminopropyl triethoxysilane.

[0017] Further, the concentration of the amino silane coupling agent in the amino silane coupling agent hydrolysis solution is 0.5-1wt%.

[0018] Further, the curing agent is one of an epoxy resin curing agent 651 and an epoxy resin curing agent DDM.

[0019] Further, the curing agent is 5-15wt% of the mass of the epoxy resin.

[0020] Further, the epoxy resin concentration of the epoxy resin solution is 20-30wt%.

[0021] Further, the temperature of the heat curing is 80-90℃, and the curing duration is 3-4h.

[0022] Further, the hydrophilic monomer is at least one of acrylic acid and acrylamide.

[0023] Further, the initiator is one of ammonium persulfate, sodium persulfate and potassium persulfate, and the initiator is 1-3wt% of the mass of the hydrophilic monomer.

[0024] Further, the concentration of the hydrophilic monomer in the mixed solution is 10-20wt%.

[0025] Further, in S6, the temperature of the heating reaction is 50-60℃.

[0026] Further, the particle size of the coal gangue crushing material is ≤1.2mm.

[0027] Further, the water reducing agent is polycarboxylic acid.

[0028] Further, the waste rubber material is a powder obtained by crushing and grinding waste rubber, and the particle size is 0.10-0.15mm.

[0029] The application also provides a preparation method of the ceramsite lightweight aggregate structure concrete, comprising the following steps: Step 1, the concrete raw materials are weighed according to the proportion, the cement, the mineral powder, the fly ash, the coal gangue crushing material, the modified coal gangue ceramsite and the waste rubber material are added into a stirrer and stirred and mixed uniformly to obtain a mixed material; Step 2, the water reducing agent and water are added into the mixed material, and the mixed material is stirred uniformly to obtain the concrete.

[0030] The application has the following beneficial effects: (1) The modified coal gangue ceramsite, the waste rubber material and the coal gangue crushing material are introduced in the application, which greatly inhibits the shrinkage of the concrete and fundamentally reduces the cracking risk from the three aspects of physical constraint, stress dispersion and microstructure.

[0031] (2) The application realizes the lightweight of the concrete, reduces the structure self-weight, and is beneficial to building energy saving and anti-seismic under the premise of ensuring the workability and strength of the concrete.

[0032] (3) The epoxy resin layer on the surface of the modified coal gangue ceramsite provides an excellent anti-permeation barrier, reduces the invasion of moisture, and the hydrophilic polymer on the surface can adjust the wettability of the ceramsite and improve the bonding force with other components of the concrete, and these characteristics together improve the anti-cracking ability of the concrete.

[0033] (4) The present application optimizes the components of the coal gangue ceramsite, and starch is added as a pore-forming agent in the raw materials of the coal gangue ceramsite. The starch decomposes at a relatively low temperature and rapidly decomposes to form pores in the early sintering stage. At this time, the pore structure is mainly open pores. Sodium carbonate and borax are used as solubilizing agents to reduce the eutectic temperature of the mixture, form a liquid phase in the sintered material, and block the pores with the liquid phase, so that the open pores are converted into closed pores. Through the synergistic effect of various components in the coal gangue ceramsite, a ceramsite with high porosity and low open porosity structure is formed.

[0034] (5) The present application simultaneously and efficiently utilizes coal gangue, fly ash, mineral powder, waste rubber, waste glass and other solid wastes, and each waste is improved in performance according to its characteristics, rather than simply filled, achieving the dual goals of turning waste into treasure and performance improvement.

[0035] (6) The present application uses three different particle sizes of modified coal gangue ceramsite as aggregate. This gradation design makes the voids between large particle ceramsite filled with medium particle ceramsite, and the voids between medium particle ceramsite filled with small particle ceramsite, achieving the closest packing of the aggregate. The amount of cement paste required to fill the voids of the aggregate is reduced, the total volume of the cement paste shrinkage is reduced, and the volume stability and strength of the concrete are improved. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0037] Embodiment 1

[0038] Preparation of modified coal gangue ceramsite: S1, prepare the raw materials of the coal gangue ceramsite base according to the proportion, mix the raw materials in the mixer to form green balls, and the mass of the mixture and water is 100:12. The raw materials of the coal gangue ceramsite base are as follows in mass fraction: Coal gangue 60 parts, silicon carbide 15 parts, borax 6 parts, volcanic ash 17 parts, sodium carbonate 5 parts, waste glass powder 10 parts, and starch 10 parts.

[0039] S2, the raw material ball is preheated at 500℃ for 1h, then heated to 1200℃ for sintering, and kept for 25min.

[0040] S3, after sintering, the coal gangue ceramic granule matrix is obtained by natural cooling to room temperature, the porosity of the coal gangue ceramic granule matrix is 40-60%, and the open porosity is 1.5-6%.

[0041] S4, the coal gangue ceramic granule matrix is immersed in a γ-aminopropyl triethoxysilane hydrolysis solution, and is placed for 15min, and then is taken out and dried, wherein the γ-aminopropyl triethoxysilane hydrolysis solution is prepared as follows: First, an ethanol and water mixture is prepared, the mass ratio of ethanol and water is 9:1, γ-aminopropyl triethoxysilane is added to the mixture, the concentration of γ-aminopropyl triethoxysilane is 0.8wt%, heated to 90℃, and hydrolyzed for 20min under stirring to obtain the hydrolysis solution.

[0042] S5, epoxy resin and curing agent DDM are dissolved in acetone to form an epoxy resin solution, the concentration of epoxy resin is 25wt%, and the curing agent DDM is 10wt% of the mass of epoxy resin, the dried ceramic granule of S4 is added to the epoxy resin solution, immersed and coated for 10min, and then taken out and heated to form an epoxy resin coating.

[0043] S6, acrylic acid is dissolved in water, ammonium persulfate is added to form a mixture, the concentration of acrylic acid is 15wt%, and the ammonium persulfate is 2wt% of the mass of acrylic acid, the ceramic granule after curing of S5 is immersed in the mixture, heated and reacted for 5h under nitrogen protection, and then the ceramic granule is taken out and dried at 80℃ to obtain modified coal gangue ceramic granule, and the modified coal gangue ceramic granule with different particle sizes is prepared, to obtain small particle size modified coal gangue ceramic granule, medium particle size modified coal gangue ceramic granule and large particle size modified coal gangue ceramic granule, the particle size of the small particle size modified coal gangue ceramic granule is <3mm, the particle size of the medium particle size modified coal gangue ceramic granule is 3-8mm, and the particle size of the large particle size modified coal gangue ceramic granule is 13-15mm.

[0044] Preparation of concrete: Step 1, the raw materials of concrete are weighed according to the proportion, cement, mineral powder, fly ash, coal gangue broken material, modified coal gangue ceramic granule and waste rubber material are added to the mixer and stirred to mix uniformly to obtain a mixture, wherein the proportion of the raw materials of the mixture is as follows: Cement 255 parts, mineral powder 30 parts, fly ash 85 parts, coal gangue broken material (particle size ≤1.2mm) 230 parts, small particle size modified coal gangue ceramic granule 245 parts, medium particle size modified coal gangue ceramic granule 300 parts, large particle size modified coal gangue ceramic granule 220 parts, waste rubber material (particle size 0.10-0.15mm) 20 parts, polycarboxylic acid water reducer 4.0 parts, and water 175 parts, the waste rubber material is a powder obtained by crushing and grinding waste rubber.

[0045] Step 2, adding polycarboxylic acid water reducing agent and water into the mixture, stirring to obtain concrete.

[0046] Example 2

[0047] The difference from Example 1 is only that the mass fraction of small particle size modified coal gangue ceramsite is adjusted to 235 parts, the mass fraction of medium particle size modified coal gangue ceramsite is adjusted to 320 parts, and the mass fraction of large particle size modified coal gangue ceramsite is adjusted to 210 parts, and other conditions and preparation steps are the same as those of Example 1.

[0048] Example 3

[0049] The difference from Example 1 is only that the mass fraction of small particle size modified coal gangue ceramsite is adjusted to 255 parts, the mass fraction of medium particle size modified coal gangue ceramsite is adjusted to 280 parts, and the mass fraction of large particle size modified coal gangue ceramsite is adjusted to 230 parts, and other conditions and preparation steps are the same as those of Example 1.

[0050] Example 4

[0051] The difference from Example 1 is only that the concentration of γ-aminopropyl triethoxysilane in the γ-aminopropyl triethoxysilane hydrolysis solution in the preparation of modified coal gangue ceramsite is adjusted to 0.5wt%, and other conditions and steps are the same as those of Example 1.

[0052] Example 5

[0053] The difference from Example 1 is only that the concentration of γ-aminopropyl triethoxysilane in the γ-aminopropyl triethoxysilane hydrolysis solution in the preparation of modified coal gangue ceramsite is adjusted to 1wt%, and other conditions and steps are the same as those of Example 1.

[0054] Example 6

[0055] The difference from Example 1 is only that the concentration of acrylic acid in the mixed solution in step S6 in the preparation of modified coal gangue ceramsite is adjusted to 10wt%, and other conditions and steps are the same as those of Example 1.

[0056] Example 7

[0057] The difference from Example 1 is only that the concentration of acrylic acid in the mixed solution in step S6 in the preparation of modified coal gangue ceramsite is adjusted to 20wt%, and other conditions and steps are the same as those of Example 1.

[0058] Example 8

[0059] The difference from Example 1 is only that the mass fraction of waste rubber material in the concrete raw material is adjusted to 10 parts. Other conditions and steps are the same as those of Example 1.

[0060] Example 9

[0061] The difference from Example 1 is that the mass fraction of the waste rubber material in the concrete raw material is adjusted to 30 parts. The other conditions and steps are the same as those in Example 1.

[0062] Comparative Example 1

[0063] The difference from Example 1 is that the modified coal gangue ceramsite is replaced by coal gangue ceramsite substrates with different particle sizes.

[0064] Preparation of coal gangue ceramsite: S1, prepare the raw materials of the coal gangue ceramsite according to the proportion, mix the raw materials in the mixer to mix uniformly, add water to the mixed material to form green balls, and the mass of the mixed material and water is 100:12, wherein the raw materials of the coal gangue ceramsite are proportioned as follows in mass fraction: Coal gangue 60 parts, silicon carbide 15 parts, borax 6 parts, volcanic ash 17 parts, sodium carbonate 5 parts, waste glass powder 10 parts, and starch 10 parts.

[0065] S2, the green balls are first preheated at 500℃ for 1h, and then sintered by increasing the temperature to 1200℃, and kept for 25min.

[0066] S3, after sintering, naturally cool to room temperature to obtain the coal gangue ceramsite, and the porosity of the coal gangue ceramsite is 40-60%, and the open porosity is 1.5-6%.

[0067] Preparation of coal gangue ceramsite with different particle sizes, to obtain small particle size coal gangue ceramsite, medium particle size coal gangue ceramsite and large particle size coal gangue ceramsite, the particle size of the small particle size coal gangue ceramsite is <3mm, the particle size of the medium particle size coal gangue ceramsite is 3-8mm, and the particle size of the large particle size coal gangue ceramsite is 13-15mm.

[0068] Preparation of concrete: Step 1, take the concrete raw materials according to the proportion, add cement, mineral powder, fly ash, coal gangue crushed material, coal gangue ceramsite and waste rubber material into the mixer to mix uniformly, to obtain the mixed material, wherein the mixed soil raw materials are proportioned as follows in mass fraction: Cement 255 parts, mineral powder 30 parts, fly ash 85 parts, coal gangue crushed material (particle size ≤1.2mm) 230 parts, small particle size coal gangue ceramsite 245 parts, medium particle size coal gangue ceramsite 300 parts, large particle size coal gangue ceramsite 220 parts, waste rubber material (particle size 0.10-0.15mm) 20 parts, polycarboxylic acid water reducer 4.0 parts, and water 175 parts. The waste rubber material is a powder obtained by crushing and grinding waste rubber.

[0069] Step 2, add polycarboxylic acid water reducer and water to the mixed material, and stir uniformly to obtain the concrete.

[0070] Comparative Example 2

[0071] The difference from example 1 is that the surface of the modified coal gangue ceramic is not hydrophilic modified.

[0072] Preparation of modified coal gangue ceramic: S1, prepare the raw materials of the coal gangue ceramic matrix according to the proportion, mix the raw materials in the mixer, add water to form green balls, and the mass of the mixture and water is 100:12, wherein the raw materials of the coal gangue ceramic matrix are as follows: Coal gangue 60 parts, silicon carbide 15 parts, borax 6 parts, volcanic ash 17 parts, sodium carbonate 5 parts, waste glass powder 10 parts, and starch 10 parts.

[0073] S2, preheat the green balls at 500℃ for 1h, then sinter at 1200℃, and keep for 25min.

[0074] S3, after sintering, naturally cool to room temperature to obtain the coal gangue ceramic matrix, and the porosity of the coal gangue ceramic matrix is 40-60%, and the open porosity is 1.5-6%.

[0075] S4, immerse the coal gangue ceramic matrix in the γ-aminopropyl triethoxysilane hydrolysis solution, and let it stand for 15min, then dry it, wherein the preparation of the γ-aminopropyl triethoxysilane hydrolysis solution is as follows: First, prepare the ethanol and water mixture, the mass ratio of ethanol and water is 9:1, add γ-aminopropyl triethoxysilane to the mixture, the concentration of γ-aminopropyl triethoxysilane is 0.8wt%, heat to 90℃, and hydrolyze for 20min under stirring to obtain the hydrolysis solution.

[0076] S5, dissolve epoxy resin and curing agent DDM in acetone to form an epoxy resin solution, the concentration of epoxy resin is 25wt%, and the curing agent DDM is 10wt% of the mass of epoxy resin, add the ceramic after drying in S4 to the epoxy resin solution, immerse and coat for 10min, then take it out and heat to form an epoxy resin coating.

[0077] Preparation of modified coal gangue ceramic with different particle sizes, small particle size modified coal gangue ceramic, medium particle size modified coal gangue ceramic and large particle size modified coal gangue ceramic, the particle size of small particle size modified coal gangue ceramic is <3mm, the particle size of medium particle size modified coal gangue ceramic is 3-8mm, and the particle size of large particle size modified coal gangue ceramic is 13-15mm.

[0078] Preparation of concrete: Step 1, weigh the concrete raw materials according to the proportion, add cement, mineral powder, fly ash, coal gangue crushed material, modified coal gangue ceramic and waste rubber material into the mixer and mix evenly, and obtain the mixture, wherein the proportion of the mixture is as follows: Cement 255 parts, mineral powder 30 parts, fly ash 85 parts, coal gangue crushed material (particle size ≤1.2 mm) 230 parts, small particle size modified coal gangue ceramic 245 parts, medium particle size modified coal gangue ceramic 300 parts, large particle size modified coal gangue ceramic 220 parts, waste rubber material (particle size 0.10-0.15 mm) 20 parts, polycarboxylic acid water reducer 4.0 parts, water 175 parts, and the waste rubber material is a powder obtained by crushing and grinding waste rubber.

[0079] Step 2, add polycarboxylic acid water reducer and water to the mixture, and stir uniformly to obtain concrete.

[0080] Comparative Example 3

[0081] The difference from Example 1 is only that no waste rubber material is added to the concrete, and the preparation of the modified coal gangue ceramic is the same as that of Example 1.

[0082] Preparation of concrete: Step 1, according to the proportion, the raw materials of the concrete are weighed, the cement, mineral powder, fly ash, coal gangue crushed material and modified coal gangue ceramic are added into the mixer and stirred uniformly to obtain a mixture, wherein the proportion of the raw materials of the mixture is as follows: Cement 255 parts, mineral powder 30 parts, fly ash 85 parts, coal gangue crushed material (particle size ≤1.2 mm) 230 parts, small particle size modified coal gangue ceramic 245 parts, medium particle size modified coal gangue ceramic 300 parts, large particle size modified coal gangue ceramic 220 parts, polycarboxylic acid water reducer 4.0 parts, water 175 parts.

[0083] Step 2, add polycarboxylic acid water reducer and water to the mixture, and stir uniformly to obtain concrete.

[0084] The water absorption rate of the coal gangue ceramic of Example 1, Example 4-Example 7, Comparative Example 1-Comparative Example 2 is detected, and the detection is carried out according to the standard GB / T 17431.2-2010.

[0085] The concrete prepared in Example 1-Example 9 and Comparative Example 1-Comparative Example 3 is made into a 150mm×150mm×150mm cubic test piece, and the performance test is carried out after curing for 28d under the curing conditions of 20℃±2℃ and relative humidity above 95%, and the detection is carried out according to the standard GB / T 50081-2019, and the results are shown in Table 1: Table 1

[0086] It can be seen from Table 1 that the concrete of the embodiment of the application has better performance than the comparative examples in terms of compressive strength and splitting tensile strength, and the compressive strength meets the requirements of LC20 grade. In Example 4 and Example 5, the silane coupling agent concentration in the hydrolysis solution is adjusted compared with Example 1, the grafting density on the surface of the ceramsite is different at different concentrations, which leads to different tightness of the epoxy resin coating and the water absorption rate of the ceramsite. Although the silane coupling agent concentration in Example 5 is higher than that in Example 1, and the water absorption rate is also lower, the reduction of the water absorption rate is not obvious, and the silane coupling agent concentration has reached the limit of the modified grafting. When the surface of the ceramsite coated with epoxy resin is modified to be hydrophilic, the concentration of the hydrophilic monomer acrylate is increased, the grafting amount of the hydrophilic polymer on the surface of the ceramsite is increased, and the bonding force between the ceramsite and other components in the concrete is better, but at the same time, the water absorption rate of the ceramsite will increase. In Example 1, Example 6 and Example 7, the performance of the concrete under the conditions of Example 1 is the best.

[0087] It should be noted that the relational terms herein such as first and second and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any such actual relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0088] Although embodiments of the application have been shown and described, it is to be understood that various modifications, substitutions, replacements and changes can be made to these embodiments without departing from the principles and spirit of the application, and the scope of the application is defined by the appended claims and their equivalents.

Claims

1. A ceramsite lightweight aggregate structural concrete, characterized by that, The following raw materials are included by mass fraction: cement 240-270 parts, mineral powder 25-35 parts, fly ash 80-95 parts, coal gangue crushed material 210-250 parts, modified coal gangue ceramsite 725-805 parts, waste rubber material 10-30 parts, water reducing agent 3.5-5 parts, and water 165-180 parts; The modified coal gangue ceramsite is obtained by coating an epoxy resin layer on the surface of a coal gangue ceramsite base and then grafting a hydrophilic polymer thereon; The porosity of the coal gangue ceramsite base is 40-60%, and the open porosity is 1.5-6%.

2. A ceramsite lightweight aggregate structural concrete according to claim 1, characterized in that, The modified coal gangue ceramsite includes small particle size modified coal gangue ceramsite, medium particle size modified coal gangue ceramsite, and large particle size modified coal gangue ceramsite; The particle size of the small particle size modified coal gangue ceramsite is <3 mm; The particle size of the medium particle size modified coal gangue ceramsite is 3-8 mm; The particle size of the large particle size modified coal gangue ceramsite is 13-15 mm; The mass ratio of the small particle size modified coal gangue ceramsite, the medium particle size modified coal gangue ceramsite, and the large particle size modified coal gangue ceramsite is (235-255):(280-320):(210-230).

3. A ceramsite lightweight aggregate structural concrete according to claim 1, characterized in that, The coal gangue ceramsite base includes the following raw materials by mass fraction: coal gangue 50-70 parts, silicon carbide 10-25 parts, borax 4-8 parts, volcanic ash 15-20 parts, sodium carbonate 3-7 parts, waste glass powder 8-12 parts, and starch 7-13 parts.

4. A ceramsite lightweight aggregate structural concrete according to claim 3, characterized in that, The preparation steps of the modified coal gangue ceramsite are as follows: S1. Prepare raw materials for the coal gangue ceramsite base according to the proportions, mix the raw materials in a mixer to form a mixture, and add water to the mixture to form green balls; S2. Preheat the green balls at 400-600°C for 0.5-1 h, then raise the temperature to 1100-1250°C for sintering, and keep the temperature for 20-30 min; S3. After sintering, naturally cool the coal gangue ceramsite base to room temperature; S4. Dip the coal gangue ceramsite base in an amino silane coupling agent hydrolysis solution, let it stand for 10-20 min, and then take it out for drying; S5. Dissolve epoxy resin and a curing agent in acetone to form an epoxy resin solution, add the dried ceramsite from S4 to the epoxy resin solution, dip it in the solution for 5-10 min, take it out, and then heat it to form an epoxy resin coating; S6. Dissolve a hydrophilic monomer in water to form a mixed solution, add an initiator to the mixed solution, dip the ceramsite from S5 in the mixed solution, heat it under nitrogen protection for 4-6 h, modify the surface of the epoxy resin coating to be hydrophilic, and then take out the ceramsite for drying to obtain the modified coal gangue ceramsite.

5. A ceramsite lightweight aggregate structural concrete according to claim 4, characterised in that, The amino silane coupling agent hydrolysis solution is obtained by hydrolyzing an amino silane coupling agent in an alcohol aqueous solution; The concentration of the amino silane coupling agent in the amino silane coupling agent hydrolysis solution is 0.5-1 wt%; The amino silane coupling agent is γ-aminopropyl triethoxysilane.

6. A ceramsite lightweight aggregate structural concrete according to claim 4, characterised in that, The curing agent is 5-15 wt% of the mass of the epoxy resin; The concentration of the epoxy resin in the epoxy resin solution is 20-30 wt%.

7. A ceramsite lightweight aggregate structural concrete according to claim 4, characterised in that, The hydrophilic monomer is at least one of acrylic acid and acrylamide; The initiator is one of ammonium persulfate, sodium persulfate, and potassium persulfate, and the mass of the initiator is 1-3 wt% of the mass of the hydrophilic monomer. The concentration of the hydrophilic monomer in the mixed solution is 10-20 wt%.

8. A ceramsite lightweight aggregate structural concrete according to claim 1, characterized by that The particle size of the coal gangue crushing material is less than or equal to 1.2 mm.

9. A ceramsite lightweight aggregate structural concrete according to claim 1, characterized in that, The waste rubber material is a powder obtained by crushing and grinding waste rubber, and the particle size is 0.10-0.15 mm.

10. A method for the production of a ceramsite lightweight aggregate structural concrete according to any one of claims 1 to 9, characterized in that, The method comprises the following steps: Step 1, according to the proportion, the concrete raw materials are weighed, the cement, the mineral powder, the fly ash, the coal gangue crushing material, the modified coal gangue ceramic and the waste rubber material are added into a stirrer and stirred and mixed uniformly to obtain a mixture; Step 2, the water reducing agent and water are added into the mixture, and the mixture is stirred uniformly to obtain the concrete.

Images