阅读说明：本技术 一种轻质高强高延性水泥基胶凝复合材料及其制备方法 (Lightweight high-strength high-ductility cement-based cementing composite material and preparation method thereof ) 是由 苟鸿翔 朱敏涛 高双双 吕恩铝 魏劼 卞成辉 于 2021-02-02 设计创作，主要内容包括：本发明公开了一种轻质高强高延性水泥基胶凝复合材料及其制备方法,所述水泥基胶凝材料按以下重量份组成：600-700份的水泥,200-300份的玻璃微珠,100-200份的硅灰,250-350份的黄砂,20-40份的轻砂,30-40份的高效减水剂,20-30份的合成纤维,230-270份的水。具体制备方法为：将600-700份的水泥,200-300份的玻璃微珠,100-200份的硅灰,250-350份的黄砂,20-40份的轻砂混合搅拌均匀,得到干料；将30-40份的高效减水剂倒入230-270份的水中搅拌均匀,加入到干料中混合搅拌均匀,得到浆料；将20-30份的合成纤维分散撒入浆料内,搅拌均匀得到轻质高强高延性水泥基胶凝复合材料。本发明具有制备方法简单,原材料种类少,所制备的水泥基胶凝复合材料容重低,强度高而且抗拉应变大。(The invention discloses a light high-strength high-ductility cement-based cementing composite material and a preparation method thereof, wherein the cement-based cementing material comprises the following components in parts by weight: 700 parts of cement in 600-materials, 300 parts of glass beads in 200-materials, 200 parts of silica fume in 100-materials, 350 parts of yellow sand in 250-materials, 20-40 parts of light sand, 30-40 parts of high-efficiency water reducing agent, 20-30 parts of synthetic fiber and 270 parts of water in 230-materials. The preparation method comprises the following steps: mixing and stirring uniformly 700 parts of 600-200-parts cement, 300 parts of 200-parts glass beads, 200 parts of 100-parts silica fume, 350 parts of 250-parts yellow sand and 20-40 parts light sand to obtain a dry material; pouring 30-40 parts of the high-efficiency water reducing agent into 230-270 parts of water, uniformly stirring, adding into the dry material, and uniformly mixing and stirring to obtain slurry; and dispersing and scattering 20-30 parts of synthetic fibers into the slurry, and uniformly stirring to obtain the light high-strength high-ductility cement-based cementitious composite. The invention has the advantages of simple preparation method, few raw material types, low volume weight of the prepared cement-based cementing composite material, high strength and large tensile strain.)

1. The lightweight high-strength high-ductility cement-based cementing composite material is characterized by comprising the following components in parts by weight: 700 parts of cement, 200 parts of glass beads, 200 parts of silica fume, 350 parts of yellow sand, 20-40 parts of light sand, 30-40 parts of a high-efficiency water reducing agent, 20-30 parts of synthetic fibers and 270 parts of water, 230; the glass beads are porous borosilicate spheresSurface area of 120m²Per kg, bulk density 256kg/m³An apparent density of 400kg/m³The grain diameter is 100-250 mu m, the yellow sand is medium sand, the fineness modulus is 2.5, the average grain diameter is 0.35-0.5mm, and the bulk density is 1480kg/m³The light sand is a mixture of coal slag, dolomite and perlite, and the bulk density is 300-400kg/m³The grain diameter is 0.08-0.135mm, the specific surface area is 2300m²/kg。

2. A lightweight high strength high ductility cement-based cementitious composite as claimed in claim 1, characterized by consisting of: 700 parts of cement, 250 parts of glass beads, 200 parts of silica fume, 250 parts of yellow sand, 40 parts of light sand, 32 parts of a high-efficiency water reducing agent, 26 parts of synthetic fibers and 240 parts of water.

3. A lightweight high strength high ductility cement-based cementitious composite as claimed in claim 1, characterized by consisting of: 700 parts of cement, 250 parts of glass beads, 200 parts of silica fume, 300 parts of yellow sand, 32 parts of light sand, 31 parts of a high-efficiency water reducing agent, 26 parts of synthetic fibers and 240 parts of water.

4. A lightweight high strength high ductility cement-based cementitious composite as claimed in claim 1, characterized by consisting of: 700 parts of cement, 250 parts of glass beads, 200 parts of silica fume, 350 parts of yellow sand, 24 parts of light sand, 30 parts of a high-efficiency water reducing agent, 26 parts of synthetic fibers and 240 parts of water.

5. The lightweight, high-strength and high-ductility cement-based cementitious composite material as claimed in claim 1, wherein the cement is ordinary portland cement, the 28d compressive strength is not less than 52.5MPa, and the true density is 3050kg/m³Having a bulk density of 1253kg/m³The specific surface area is 455m²/kg。

6. A lightweight, high strength, high ductility cement-based cementitious composite as claimed in claim 1, wherein said method of preparing light sand comprises the steps of:

step one, crushing the coal cinder, the dolomite and the perlite by using a jaw crusher, pouring the crushed materials into a ball mill for ball milling for 4-5h, and then sieving the obtained powder with a 350-mesh sieve, wherein the mass ratio of the coal cinder, the dolomite and the perlite is 10:1: 2;

step two, adding the powder obtained in the step one into a granulator for stirring, wherein the stirring speed is 150r/min, spraying water mist accounting for 3% of the mass of the powder to the powder in the stirring process, and stopping stirring when the particle size of the particles is between 80 meshes and 120 meshes to obtain semi-finished product particles;

step three, transferring the semi-finished product particles obtained in the step two into a drying kiln, keeping the temperature at 105 +/-5 ℃ for drying for 2 hours, cooling to room temperature, and screening out particles smaller than 80 meshes to obtain semi-finished product light sand;

step four, transferring the semi-finished product light sand obtained in the step three into a rotary kiln for calcination, wherein the rotating speed of the rotary kiln is 250r/min, heating to 980 ℃ at the speed of 10 ℃/min, keeping for 1-1.5h, then heating to 1100 ℃ again, and keeping for 2 h;

and step five, cooling the calcined semi-finished product light sand in a natural cooling mode, and cooling to room temperature to obtain the finished product light sand.

7. A lightweight, high strength, high ductility cementitious composite material as claimed in claim 1 wherein said silica fume activity index is greater than 95% and true density 1950kg/m³Having a bulk density of 390kg/m³The specific surface area is 22000m²Per kg, particle size 0.1-0.3 μm.

8. The lightweight, high-strength and high-ductility cement-based cementitious composite as claimed in claim 1, wherein the high efficiency water reducer is PCA type polycarboxylate water reducer, the water reduction rate is more than 30%, and the density is 1050-³。

9. The lightweight, high strength, high ductility cement-based cementitious composite as claimed in claim 1, wherein said synthetic fibers are high modulus high strength polyvinyl alcohol fibers having a length of 12mm, a diameter of 0.04mm, a density of 970kg/m3, a tensile strength of 1600MPa and an elastic modulus of 38 GPa.

10. A method for preparing a lightweight high-strength high-ductility cement-based cementitious composite material as claimed in any one of claims 1 to 8, comprising the steps of:

weighing cement, glass beads, silica fume, yellow sand, light sand, a high-efficiency water reducing agent, synthetic fibers and water according to parts by weight;

step two, mixing and stirring cement, glass beads, silica fume, yellow sand and light sand uniformly to obtain a dry material A;

step three, adding the high-efficiency water reducing agent into water, uniformly stirring, adding the high-efficiency water reducing agent into the dry material A, and uniformly mixing and stirring to obtain slurry B;

and step four, dispersing and scattering the synthetic fibers into the slurry B, and uniformly stirring to obtain the lightweight high-strength high-ductility cement-based cementitious composite.

Technical Field

The invention belongs to the technical field of cement-based cementing material preparation, and particularly relates to a lightweight high-strength high-ductility cement-based cementing composite material and a preparation method thereof.

Background

The high-ductility cement-based cementitious composite is a high-ductility composite formed by adding certain short fibers with good performance into a cement-based material, and only under the condition that the volume doping amount of the fibers is about 2.0%, the obtained composite can show remarkable strain hardening characteristics after being hardened, the ultimate tensile strain can stably reach more than 3%, and the high-ductility cement-based cementitious composite shows good crack resistance and toughness, and meanwhile, the distribution of cracks of the high-ductility cement-based cementitious composite under the load action has the characteristics of multiple cracks, small width, slow development and multiple energy release outlets. The fiber reinforced cement-based cementitious composite material can greatly improve the properties of a base material and improve the properties of the base material such as cracking resistance, permeability resistance, impact toughness, durability, high temperature resistance, corrosion resistance and the like, so the fiber reinforced cement-based cementitious composite material is concerned by people in engineering circles in recent years and becomes one of hot spots of engineering material research.

In high-rise and super high-rise building structures, large-span bridges, urban overpasses and ocean engineering, light-weight and high-strength concrete is widely applied in order to reduce the self weight of the structure and the construction cost. The lightweight aggregate mainly adopted in the concrete at present is lightweight porous materials such as ceramsite, expanded clay, expanded shale and the like, the use of the materials can obviously reduce the volume weight of the concrete, but the problems that the lightweight aggregate floats on the surface of a mixture, cracks are expanded more quickly and the like are easily caused. Therefore, it is necessary to develop a lightweight porous fine aggregate with more excellent properties to solve the problems of the existing lightweight aggregate, and simultaneously apply the excellent property of high ductility to lightweight high-strength concrete, so that the homogeneity of the lightweight high-strength concrete can be improved, the durability of the concrete such as crack resistance, impact resistance, shock resistance and the like can be obviously improved, and the lightweight porous fine aggregate becomes an excellent multifunctional engineering cement-based cementitious composite material.

The publication No. CN 109761564A discloses a light-weight high-ductility cement-based cementitious composite, which comprises 442 parts by weight of cement 334-containing materials, 552 parts by weight of fly ash 223-containing materials, 76-78 parts by weight of silica fume, 8.5-8.6 parts by weight of expanded perlite, 129 parts by weight of floating bead 127-containing materials, 19.3-19.5 parts by weight of high-efficiency water reducing agent, 28.9-29.3 parts by weight of shrinkage reducing agent, 1.16-1.17 parts by weight of thickening agent, 7.1-11.9 parts by weight of glass fiber, 0.1-234 parts by weight of mineral powder and 0.1-20 parts by weight of early strength agent, and the bulk weight of the cementitious composite is not higher than 1400kg/m³The flexural strength is higher than 5MPa, and the compressive strength is higher than 20 MPa. However, the method has the advantages of various raw materials, higher cost, lower compressive strength and rupture strength, and no uniaxial tensile stress strain test result for visually evaluating the ductility of the cement-based cementing material.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a lightweight high-strength high-ductility cement-based cementing composite material which can reduce the self weight of the cement-based cementing material and keep good mechanical property and extensibility. In addition, the invention also provides a preparation method of the lightweight high-strength high-ductility cement-based cementitious composite, the preparation method has simple preparation process and few raw material types, the prepared cement-based cementitious composite has low volume weight, excellent mechanical properties such as compressive strength, tensile strength and the like, high fracture ductility and toughness, and greatly improved durability such as crack resistance, earthquake resistance, fire resistance, freezing resistance and the like.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention provides a lightweight high-strength high-ductility cement-based cementing composite material, which comprises the following components in parts by weight: 700 parts of cement, 200 parts of glass beads, 200 parts of silica fume, 350 parts of yellow sand, 20-40 parts of light sand, 30-40 parts of a high-efficiency water reducing agent, 20-30 parts of synthetic fibers and 270 parts of water, 230; the glass beads are porous borosilicate spheres with the specific surface area of 120m²Per kg, bulk density 256kg/m³An apparent density of 400kg/m³The main range of the particle size distribution is between 100-250 mu m, the yellow sand is medium sand, the fineness modulus is 2.5, the average particle size is 0.35-0.5mm, and the bulk density is 1480kg/m³。

Further, the preparation method of the light sand comprises the following steps:

step one, crushing the coal cinder, the dolomite and the perlite by using a jaw crusher, pouring the crushed materials into a ball mill for ball milling for 4-5h, and sieving the obtained powder with a 350-mesh sieve. Wherein the mass ratio of the coal cinder, the dolomite and the perlite is 10:1:2, the coal cinder is a main component of the light sand, the dolomite is mainly used for generating pores of the light sand, and the perlite is used as an auxiliary filling material;

secondly, adding the obtained powder into a granulator for stirring, wherein the stirring speed is 150r/min, spraying water mist accounting for 3 percent of the mass of the powder in the stirring process, and stopping stirring when the particle size of the particles is between 80 meshes and 120 meshes to obtain semi-finished product particles;

step three, transferring the semi-finished product particles into a drying kiln, keeping the temperature at 105 +/-5 ℃ for drying for 2 hours, cooling to room temperature, and screening out particles smaller than 80 meshes to obtain semi-finished product light sand;

transferring the semi-finished product light sand into a rotary kiln for calcination, wherein the rotating speed of the rotary kiln is 250r/min, heating to 980 ℃ at the speed of 10 ℃/min, keeping for 1-1.5h, then heating to 1100 ℃, and keeping for 2 h;

and step five, cooling the calcined semi-finished product light sand in a natural cooling mode, and cooling to room temperature to obtain the finished product light sand.

Prepared light sandThe bulk density is only 300-400kg/m³Fine particles with particle size distribution of 0.08-0.135mm, uniformly distributed micro pores on the surface and inside, and specific surface area up to 2300m²/kg。

By adopting the technical scheme, the lightweight and porous characteristics of the light sand can reduce the volume weight of the cement-based gelled composite material, and the larger specific surface area of the light sand is easier to absorb water, is beneficial to internal maintenance of the cement-based gelled composite material and also provides a large number of hydration reaction sites, so that the hydration reaction degree is improved; the glass beads also have the spherical characteristics of light weight and multiple pores, the volume weight of the cement-based cementing composite material can be greatly reduced, and the spherical shape can improve the fluidity of slurry; in addition, the high-efficiency water reducing agent is used for reducing the using amount of water and increasing the working performance of the freshly mixed cement-based cementing composite material; the high-elastic modulus high-strength polyvinyl alcohol fiber is used for improving mechanical properties such as toughness, tensile strength and the like, and durability such as crack resistance, heat resistance and the like of the cement-based cementing composite material.

The high-efficiency water reducing agent is further composed of the following components of 700 parts of cement, 250 parts of glass beads, 200 parts of silica fume, 250 parts of yellow sand, 40 parts of light sand, 32 parts of a high-efficiency water reducing agent, 26 parts of synthetic fibers and 240 parts of water.

Further, the composition comprises the following components: 700 parts of cement, 250 parts of glass beads, 200 parts of silica fume, 300 parts of yellow sand, 32 parts of light sand, 31 parts of a high-efficiency water reducing agent, 26 parts of synthetic fibers and 240 parts of water.

Further, the composition comprises the following components: 700 parts of cement, 250 parts of glass beads, 200 parts of silica fume, 350 parts of yellow sand, 24 parts of light sand, 30 parts of a high-efficiency water reducing agent, 26 parts of synthetic fibers and 240 parts of water.

Further, the cement is ordinary portland cement, the 28d compressive strength is more than or equal to 52.5MPa, and the true density is 3050kg/m³Having a bulk density of 1253kg/m³The specific surface area is 455m²/kg。

Further, the silica fume activity index is more than 95%, and the true density is 1950kg/m³Having a bulk density of 390kg/m³The specific surface area is 22000m²Per kg, the particle size distribution lies predominantly between 0.1 and 0.3. mu.m.

Further, the high-efficiency water reducing agent is a PCA type polycarboxylate water reducing agent, the water reducing rate is more than 30 percent, and the density is 1050-³。

Further, the synthetic fiber is high elastic modulus high strength polyvinyl alcohol fiber with length of 12mm, diameter of 0.04mm and density of 970kg/m³The tensile strength was 1600MPa, and the elastic modulus was 38 GPa.

In a second aspect of the present invention, a method for preparing a lightweight, high-strength and high-ductility cement-based cementitious composite is provided, which is used for preparing the lightweight, high-strength and high-ductility cement-based cementitious composite, and comprises the following steps:

weighing cement, glass beads, silica fume, yellow sand, light sand, a high-efficiency water reducing agent, synthetic fibers and water according to parts by weight;

step two, mixing and stirring cement, glass beads, silica fume, yellow sand and light sand uniformly to obtain a dry material A;

step three, adding the high-efficiency water reducing agent into water, uniformly stirring, adding the high-efficiency water reducing agent into the dry material A, and uniformly mixing and stirring to obtain slurry B;

and step four, dispersing and scattering the synthetic fibers into the slurry B, and uniformly stirring to obtain the lightweight high-strength high-ductility cement-based cementitious composite.

Compared with the prior art, the invention has the beneficial effects that:

(1) the invention adopts the specially-made light sand, has the advantages of lighter weight, smaller particle size, more pores and the like compared with the light fine aggregate such as common ceramic sand and the like, and is a better raw material for preparing light high-strength concrete.

(2) In the raw materials used by the invention, the light sand and the glass beads are used in an isovolumetric mode to replace fly ash, so that the volume weight of the cement-based cementing composite material can be greatly reduced, and the light sand prepared by the method has the characteristics of high specific surface area, high water absorption and the like, so that the light sand can provide a hydration reaction point and can provide internal maintenance conditions, and the hydration reaction degree of the cementing material is improved. The cement-based cementing composite material prepared by the invention has the lowest volume weight of only 1436kg/m³The highest compressive strength can reach 45.9 MPa.

(3) The high-elastic modulus high-strength polyvinyl alcohol fiber adopted in the invention can obviously increase the toughness and tensile property of the cement-based gelled composite material, greatly improve the mechanical property and crack width of the cement-based gelled composite material and improve the durability of the cement-based gelled composite material. The strain rate of the cement-based cementing composite material prepared by the invention can reach 4.6%, and the tensile strength can reach 4.1 MPa.

(4) The invention has the advantages of less variety of required raw materials, simple process flow and lower preparation cost.

Drawings

FIG. 1 is a strain diagram of tensile stress of a lightweight, high strength, high ductility cementitious composite of example 2;

FIG. 2 is a graph of the tensile stress strain of the lightweight, high strength, and high ductility cementitious composite of example 4.

Detailed Description

The technical solutions of the present invention will be described clearly and completely in the following embodiments of the present invention, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without inventive effort based on the embodiments of the present invention, are within the scope of the present invention.

The invention provides a lightweight high-strength high-ductility cement-based cementing composite material which comprises the following components in parts by weight: 700 parts of cement, 200 parts of glass beads, 200 parts of silica fume, 350 parts of yellow sand, 20-40 parts of light sand, 30-40 parts of a high-efficiency water reducing agent, 20-30 parts of synthetic fibers and 270 parts of water, 230; the glass beads are porous borosilicate spheres with the specific surface area of 120m²Per kg, bulk density 256kg/m³An apparent density of 400kg/m³The main range of the particle size distribution is between 100-250 mu m, the yellow sand is medium sand, the fineness modulus is 2.5, the average particle size is 0.35-0.5mm, and the bulk density is 1480kg/m³. The cement is ordinary portland cement, the 28d compressive strength is more than or equal to 52.5MPa, and the true density is 3050kg/m³Having a bulk density of 1253kg/m³The specific surface area is 455m²In terms of/kg. The silica fume activityThe index is more than 95 percent, and the true density is 1950kg/m³Having a bulk density of 390kg/m³The specific surface area is 22000m²Per kg, the particle size distribution lies predominantly between 0.1 and 0.3. mu.m. The light sand has the bulk density of 300-400kg/m³The particle size distribution is mainly between 0.08 and 0.135mm, and the specific surface area reaches 2300m²In terms of/kg. The high-efficiency water reducing agent is a PCA type polycarboxylate water reducing agent, the water reducing rate is more than 30 percent, and the density is 1050-³. The synthetic fiber is high-elastic modulus high-strength polyvinyl alcohol fiber with the length of 12mm, the diameter of 0.04mm and the density of 970kg/m³The tensile strength was 1600MPa, and the elastic modulus was 38 GPa.

The raw materials used in the examples are, if not specified, all known and commercially available chemical raw materials.

Example 1

The embodiment provides a preparation method of light sand, which comprises the following steps:

step one, crushing the coal cinder, the dolomite and the perlite by using a jaw crusher, pouring the crushed materials into a ball mill for ball milling for 4-5h, and sieving the obtained powder with a 350-mesh sieve. Wherein the mass ratio of the coal cinder, the dolomite and the perlite is 10:1:2, the coal cinder is a main component of the light sand, the dolomite is mainly used for generating pores of the light sand, and the perlite is used as an auxiliary filling material;

secondly, adding the obtained powder into a granulator for stirring, wherein the stirring speed is 150r/min, spraying water mist accounting for 3 percent of the mass of the powder in the stirring process, and stopping stirring when the particle size of the particles is between 80 meshes and 120 meshes to obtain semi-finished product particles;

step three, transferring the semi-finished product particles into a drying kiln, keeping the temperature at 105 +/-5 ℃ for drying for 2 hours, cooling to room temperature, and screening out particles smaller than 80 meshes to obtain semi-finished product light sand;

transferring the semi-finished product light sand into a rotary kiln for calcination, wherein the rotating speed of the rotary kiln is 250r/min, heating to 980 ℃ at the speed of 10 ℃/min, keeping for 1-1.5h, then heating to 1100 ℃, and keeping for 2 h;

and step five, cooling the calcined semi-finished product light sand in a natural cooling mode, and cooling to room temperature to obtain the finished product light sand.

The bulk density of the prepared light sand is only 300-³Fine particles with particle size distribution of 0.08-0.135mm, uniformly distributed micro pores on the surface and inside, and specific surface area up to 2300m²And/kg, is a better raw material for preparing light high-strength concrete.

Example 2

A lightweight high-strength high-ductility cement-based cementitious composite is prepared by the following preparation steps:

step one, mixing and stirring 700 parts of cement, 230 parts of silica fume, 250 parts of yellow sand, 40 parts of light sand and 250 parts of glass beads uniformly to obtain a dry material A1;

step two, pouring 32 parts of high-efficiency water reducing agent into 240 parts of water, uniformly stirring, adding the mixture into the dry material A1, and uniformly mixing and stirring to obtain slurry B1;

and step three, scattering 26 parts of polyvinyl alcohol fibers into the slurry B1 in a dispersing manner, and uniformly stirring to obtain the light high-strength high-ductility cement-based cementitious composite material. FIG. 1 is a strain diagram of the tensile stress of the lightweight high-strength high-ductility cementitious composite of example 1.

Example 3

A lightweight high-strength high-ductility cement-based cementitious composite is prepared by the following preparation steps:

step one, mixing and stirring 700 parts of cement, 230 parts of silica fume, 300 parts of yellow sand, 32 parts of light sand and 250 parts of glass beads uniformly to obtain a dry material A1;

step two, pouring 31 parts of the high-efficiency water reducing agent into 240 parts of water, uniformly stirring, adding the high-efficiency water reducing agent into the dry material A1, and uniformly mixing and stirring to obtain slurry B1;

and step three, scattering 26 parts of polyvinyl alcohol fibers into the slurry B1 in a dispersing manner, and uniformly stirring to obtain the light high-strength high-ductility cement-based cementitious composite material.

Example 4

A lightweight high-strength high-ductility cement-based cementitious composite is prepared by the following preparation steps:

step one, mixing and stirring 700 parts of cement, 230 parts of silica fume, 350 parts of yellow sand, 24 parts of light sand and 250 parts of glass beads uniformly to obtain a dry material A1;

step two, pouring 30 parts of the high-efficiency water reducing agent into 240 parts of water, uniformly stirring, adding the high-efficiency water reducing agent into the dry material A1, and uniformly mixing and stirring to obtain slurry B1;

and step three, scattering 26 parts of polyvinyl alcohol fibers into the slurry B1 in a dispersing manner, and uniformly stirring to obtain the light high-strength high-ductility cement-based cementitious composite material. FIG. 2 is a strain diagram of the tensile stress of the lightweight high-strength high-ductility cement-based cementitious composite of example 3.

The parts by weight of the components in example 2 and example 4 are summarized in Table 1.

Performance test

1. A method for testing a lightweight, High-strength and High-ductility Cement-based cementitious composite is provided, and the Cement-based cementitious composite obtained in examples 2 to 4 is subjected to uniaxial tensile property test of the Cement-based cementitious composite according to the standard 'Recommendations for Design and Construction of High Performance Fiber Reinforced Composites with Multiple Fiber Cracks (HPFRCC)' (GC82), so that the tensile strength and the strain rate of the Cement-based cementitious composite are obtained.

2. The cement-based cementitious composite materials obtained in examples 2-4 are subjected to compressive strength tests of cement-based cementitious composite materials 7d and 28d according to the national standard 'mechanical property test method for ordinary cement-based cementitious composite materials' (GB/T50081-2002).

4. The cement-based cementitious composite materials obtained in examples 2 to 4 were subjected to a test of the bulk density of the cementitious composite materials according to the Standard test methods for bulk density and air content of New pour cementitious composite materials (JIS A1116-1998).

The test data are shown in Table 2.

The implementation effect is as follows:

from examples 2-4, it can be seen that the volume weight of the cement-based cementitious composite can be greatly reduced by replacing yellow sand and fly ash with light sand and glass beads in equal volumes. Meanwhile, the internal curing capacity and the large specific surface area of the light sand improve the hydration degree of the cementing material, and the glass beads also provide high compressive strength, so that the strength of the cement-based cementing composite material is improved. The good bridging capacity of the high-elastic modulus high-strength polyvinyl alcohol fiber and the matrix material greatly improves the tensile strain rate of the cement-based cementing composite material and obviously improves the toughness of the cement-based cementing composite material. As the light sand content increased from 24 parts to 40 parts, the volume weight of the cement-based cementitious composite decreased by 207kg/m³But the compressive strength is reduced by only 5.8MPa, the tensile strength is also reduced by only 0.8MPa, and the tensile strain is increased by 0.6 percent, which is mainly benefited by the internal curing effect of light sand and the smaller particle size, so that the comprehensive performance of the cement-based cementitious composite material is optimized. In general, the raw materials of the invention are few in variety, the process flow is simple, and the prepared cement-based cementing composite material has the advantages of light weight, high strength, good toughness and lower preparation cost.

Although the present invention has been described in detail with respect to the above embodiments, it will be understood by those skilled in the art that modifications or improvements based on the disclosure of the present invention may be made without departing from the spirit and scope of the invention, and these modifications and improvements are within the spirit and scope of the invention.