Polymer cement concrete additive and preparation method thereof

文档序号：580488 发布日期：2021-05-25 浏览：31次中文

阅读说明：本技术 一种高分子水泥混凝土添加剂及其制备方法 (Polymer cement concrete additive and preparation method thereof ) 是由夏梅于 2021-01-22 设计创作，主要内容包括：本发明适用于混凝土添加剂技术领域,提供了一种高分子水泥混凝土添加剂,包括以下按照重量份的原料：乙烯-醋酸乙烯共聚物80～120份、聚氯乙烯树脂30～50份、改性硅灰石粉15～35份、改性纤维素20～40份、无机纳米颗粒10～18份、稳定剂2～6份、偶联剂2～6份和去离子水140～180份。本发明还提供了一种如上所述的高分子水泥混凝土添加剂的制备方法,通过对纤维素进行改性处理,增加纤维素表面亲水性氨基数量,提高添加剂的保水性能；同时利用甲基丙烯酸三氟乙酯对硅灰石粉进行改性,增强了添加剂与混凝土表面的结合力,使表面变得更致密,致密的养护膜有效阻止了混凝土表面水分的蒸发,提高了保水效果。(The invention is suitable for the technical field of concrete additives, and provides a polymer cement concrete additive which comprises the following raw materials in parts by weight: 80-120 parts of ethylene-vinyl acetate copolymer, 30-50 parts of polyvinyl chloride resin, 15-35 parts of modified wollastonite powder, 20-40 parts of modified cellulose, 10-18 parts of inorganic nanoparticles, 2-6 parts of stabilizer, 2-6 parts of coupling agent and 140-180 parts of deionized water. The invention also provides a preparation method of the polymer cement concrete additive, which is characterized in that cellulose is modified to increase the number of hydrophilic amino groups on the surface of the cellulose and improve the water retention property of the additive; meanwhile, the wollastonite powder is modified by utilizing the trifluoroethyl methacrylate, so that the binding force of the additive and the surface of the concrete is enhanced, the surface becomes more compact, the compact curing film effectively prevents the evaporation of the water on the surface of the concrete, and the water retention effect is improved.)

1. The polymer cement concrete additive is characterized by comprising the following raw materials in parts by weight:

80-120 parts of ethylene-vinyl acetate copolymer, 30-50 parts of polyvinyl chloride resin, 15-35 parts of modified wollastonite powder, 20-40 parts of modified cellulose, 10-18 parts of inorganic nanoparticles, 2-6 parts of stabilizer, 2-6 parts of coupling agent and 140-180 parts of deionized water.

2. The polymer cement concrete additive according to claim 1, which comprises the following raw materials in parts by weight:

90-110 parts of ethylene-vinyl acetate copolymer, 35-45 parts of polyvinyl chloride resin, 20-30 parts of modified wollastonite powder, 25-35 parts of modified cellulose, 12-16 parts of inorganic nanoparticles, 3-5 parts of stabilizer, 3-5 parts of coupling agent and 150-170 parts of deionized water.

3. The polymer cement concrete additive according to claim 1, which comprises the following raw materials in parts by weight:

100 parts of ethylene-vinyl acetate copolymer, 40 parts of polyvinyl chloride resin, 25 parts of modified wollastonite powder, 30 parts of modified cellulose, 14 parts of inorganic nano-particles, 4 parts of stabilizer, 4 parts of coupling agent and 160 parts of deionized water.

4. The polymer cement concrete additive according to claim 1, wherein the stabilizer is magnesium stearate.

5. The polymer cement concrete additive of claim 1 wherein the coupling agent is a titanate.

6. The polymer cement concrete additive according to claim 1, wherein the modified wollastonite powder is prepared by the following steps:

adding wollastonite powder into trifluoroethyl methacrylate, stirring for 2-3 h at 40-60 ℃, centrifuging for 0.5h, and then placing in a vacuum drying oven for drying for 12-18 h at the drying temperature of 80-85 ℃ to obtain the modified wollastonite powder.

7. The polymer cement concrete additive according to claim 1, wherein the modified cellulose is prepared by the following method:

the method comprises the steps of adjusting the pH value of cellulose to 7.5-7.8 by using a sodium hydroxide solution, then putting the cellulose into a dryer for drying, and grinding the cellulose into 60-mesh powder to obtain the modified cellulose.

8. The polymer cement concrete additive according to claim 1, wherein the inorganic nanoparticles are nano zirconia.

9. A method for preparing the polymer cement concrete additive according to any one of claims 1 to 8, which comprises the following steps:

1) crushing and sieving modified wollastonite powder and modified cellulose, adding the crushed and sieved modified wollastonite powder and modified cellulose into deionized water, stirring for 20-30 min, adding a coupling agent, keeping the temperature, stirring for 30-50 min, filtering and drying to obtain composite powder;

2) adding ethylene-vinyl acetate copolymer, polyvinyl chloride resin and inorganic nano particles into deionized water, and uniformly mixing to obtain a mixed solution;

3) and adding the composite powder into the mixed solution, adding a stabilizer, preserving the heat for 1-2 hours, cooling to room temperature, and adjusting the pH value to 7-8 to obtain the polymer cement concrete additive.

10. The method for preparing the polymer cement concrete additive according to claim 9, wherein the heat preservation temperature in the step 1) is 40-60 ℃.

Technical Field

The invention relates to the technical field of concrete additives, in particular to a polymer cement concrete additive and a preparation method thereof.

Background

The cement concrete is artificial stone which is prepared by taking cement as a main cementing material, adding water, sand, stones and chemical additives and mineral admixtures if necessary, mixing the materials according to a proper proportion, uniformly stirring, densely molding, curing and hardening. The cement concrete is mainly divided into two stages and states: plastic state before setting and hardening, namely newly mixed cement concrete or cement concrete mixture; hardened state, i.e. hardened cement concrete.

In the preparation of concrete, it is often necessary to incorporate concrete additives therein in order to improve and enhance the overall performance of the concrete. The concrete additive is one of indispensable components for ensuring excellent workability, strength and durability of concrete, and is effective in improving and adjusting the performance of concrete. Concrete additives are widely varied, such as water reducers, air entrainers and pumpants for improving the rheological properties of concrete mixtures, retarders, early strength agents and accelerators for adjusting the setting time and setting properties of concrete, air entrainers, water repellents and rust inhibitors for improving the durability of concrete, air entrainers, expanding agents, colorants, anti-freezing agents, water repellents and pumpants for improving other properties of concrete, and the like. The additives have positive effects on improving the performance of concrete and improving the quality of construction engineering.

The curing agent is one of concrete additives, can form a layer of continuous impervious airtight curing film on the surface of concrete, isolate the surface of the concrete from air, and reduce water evaporation, so that the hydration of the concrete is completed to the maximum extent by utilizing the water of the concrete, and the water of the concrete is enough to ensure that the concrete achieves the curing effect. The curing agents on the market at present mainly comprise water glass type curing agents and common paraffin emulsion type curing agents, the water retention rate of the water glass type curing agents can not meet the standard requirements, and the common paraffin emulsion curing agents are sensitive to high-temperature environments and are easy to soften and flow at high temperature although the water retention rate is higher.

Disclosure of Invention

The embodiment of the invention provides a polymer cement concrete additive, aiming at improving the water retention property of the additive by modifying cellulose, increasing the number of hydrophilic amino groups on the surface of the cellulose and improving the water retention property of the fiber and adding the modified cellulose into a concrete additive base material; meanwhile, the wollastonite powder is modified by utilizing trifluoroethyl methacrylate, so that fluorine atoms with high fluorine electronegativity surround carbon chains to form a spiral structure, a hydrophobic effect is achieved, the carbon bonds are protected from being easily damaged by chemical media, a hydroxyl group can be utilized to perform a chemical bonding effect with silicon atoms on the surface of concrete, the bonding force of an additive and the surface of the concrete is enhanced, the surface is more compact, the compact maintenance film effectively prevents the evaporation of water on the surface of the concrete, and the water retention effect is improved.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a polymer cement concrete additive comprises the following raw materials in parts by weight:

Further, the stabilizer is magnesium stearate.

Further, the coupling agent is a titanate.

Further, the preparation method of the modified wollastonite powder comprises the following steps:

Further, the preparation method of the modified cellulose comprises the following steps:

Further, the inorganic nanoparticles are nano zirconia.

The invention also provides a preparation method of the polymer cement concrete additive, which comprises the following steps:

2) adding ethylene-vinyl acetate copolymer, polyvinyl chloride resin and inorganic nano particles into deionized water, and uniformly mixing to obtain a mixed solution;

Further, the heat preservation temperature in the step 1) is 40-60 ℃.

The invention has the following beneficial effects:

according to the invention, the cellulose is modified, the number of hydrophilic amino groups on the surface of the cellulose is increased, the water retention of the fiber is improved, and the modified cellulose is added into a concrete additive base material, so that the water retention of the additive is improved; meanwhile, the wollastonite powder is modified by utilizing trifluoroethyl methacrylate, so that fluorine atoms with high fluorine electronegativity surround carbon chains to form a spiral structure, a hydrophobic effect is achieved, the carbon bonds are protected from being easily damaged by chemical media, a hydroxyl group can be utilized to perform a chemical bonding effect with silicon atoms on the surface of concrete, the bonding force of an additive and the surface of the concrete is enhanced, the surface is more compact, the compact maintenance film effectively prevents the evaporation of water on the surface of the concrete, and the water retention effect is improved.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Specifically, the embodiment of the invention provides a polymer cement concrete additive, which comprises the following raw materials in parts by weight:

In the examples of the present invention, the stabilizer is magnesium stearate.

In the embodiment of the invention, the coupling agent is titanate.

In the embodiment of the invention, the preparation method of the modified wollastonite powder comprises the following steps:

The wollastonite powder is modified by utilizing trifluoroethyl methacrylate, so that fluorine atoms with high fluorine electronegativity surround carbon chains to form a spiral structure, a hydrophobic effect is achieved, the carbon bonds are protected from being easily damaged by chemical media, a hydroxyl group can be utilized to perform a chemical bonding effect with silicon atoms on the surface of concrete, the bonding force of an additive and the surface of the concrete is enhanced, the surface is made to be more compact, the compact maintenance film effectively prevents the evaporation of water on the surface of the concrete, and the water retention effect is improved.

In the embodiment of the invention, the preparation method of the modified cellulose comprises the following steps:

The modified cellulose is added into the concrete additive base material, so that the water retention performance of the additive is improved.

In the embodiment of the invention, the inorganic nanoparticles are nano zirconia.

The embodiment of the invention also provides a preparation method of the polymer cement concrete additive, which comprises the following steps:

2) adding ethylene-vinyl acetate copolymer, polyvinyl chloride resin and inorganic nano particles into deionized water, and uniformly mixing to obtain a mixed solution;

In the embodiment of the invention, the heat preservation temperature in the step 1) is 40-60 ℃.

The technical solution and the technical effect of the present invention will be further described by specific examples.

Example 1

Adding wollastonite powder into trifluoroethyl methacrylate, stirring at 50 ℃ for 3h, centrifuging for 0.5h, and then placing in a vacuum drying oven for drying for 14h at the drying temperature of 80 ℃ to obtain modified wollastonite powder for later use; adjusting the pH value of the cellulose to 7.5 by using a sodium hydroxide solution, then putting the cellulose into a dryer for drying, and grinding the cellulose into 60-mesh powder to obtain modified cellulose for later use; crushing and sieving 15g of modified wollastonite powder and 20g of modified cellulose, adding into 80g of deionized water, stirring for 30min, adding 4g of titanate, keeping the temperature, stirring for 50min, filtering and drying to obtain composite powder; adding 100g of ethylene-vinyl acetate copolymer, 40g of polyvinyl chloride resin and 14g of inorganic nanoparticles into 80g of deionized water, and uniformly mixing to obtain a mixed solution; and adding the composite powder into the mixed solution, adding 4g of magnesium stearate, keeping the temperature for 2h, cooling to room temperature, and adjusting the pH value to 7 to obtain the polymer cement concrete additive.

Example 2

Adding wollastonite powder into trifluoroethyl methacrylate, stirring at 50 ℃ for 3h, centrifuging for 0.5h, and then placing in a vacuum drying oven for drying for 14h at the drying temperature of 80 ℃ to obtain modified wollastonite powder for later use; adjusting the pH value of the cellulose to 7.5 by using a sodium hydroxide solution, then putting the cellulose into a dryer for drying, and grinding the cellulose into 60-mesh powder to obtain modified cellulose for later use; crushing and sieving 20g of modified wollastonite powder and 20g of modified cellulose, adding into 80g of deionized water, stirring for 30min, adding 4g of titanate, keeping the temperature, stirring for 50min, filtering and drying to obtain composite powder; adding 100g of ethylene-vinyl acetate copolymer, 40g of polyvinyl chloride resin and 14g of inorganic nanoparticles into 80g of deionized water, and uniformly mixing to obtain a mixed solution; and adding the composite powder into the mixed solution, adding 4g of magnesium stearate, keeping the temperature for 2h, cooling to room temperature, and adjusting the pH value to 7 to obtain the polymer cement concrete additive.

Example 3

Adding wollastonite powder into trifluoroethyl methacrylate, stirring at 50 ℃ for 3h, centrifuging for 0.5h, and then placing in a vacuum drying oven for drying for 14h at the drying temperature of 80 ℃ to obtain modified wollastonite powder for later use; adjusting the pH value of the cellulose to 7.5 by using a sodium hydroxide solution, then putting the cellulose into a dryer for drying, and grinding the cellulose into 60-mesh powder to obtain modified cellulose for later use; crushing and sieving 25g of modified wollastonite powder and 20g of modified cellulose, adding into 80g of deionized water, stirring for 30min, adding 4g of titanate, keeping the temperature, stirring for 50min, filtering and drying to obtain composite powder; adding 100g of ethylene-vinyl acetate copolymer, 40g of polyvinyl chloride resin and 14g of inorganic nanoparticles into 80g of deionized water, and uniformly mixing to obtain a mixed solution; and adding the composite powder into the mixed solution, adding 4g of magnesium stearate, keeping the temperature for 2h, cooling to room temperature, and adjusting the pH value to 7 to obtain the polymer cement concrete additive.

Example 4

Adding wollastonite powder into trifluoroethyl methacrylate, stirring at 50 ℃ for 3h, centrifuging for 0.5h, and then placing in a vacuum drying oven for drying for 14h at the drying temperature of 80 ℃ to obtain modified wollastonite powder for later use; adjusting the pH value of the cellulose to 7.5 by using a sodium hydroxide solution, then putting the cellulose into a dryer for drying, and grinding the cellulose into 60-mesh powder to obtain modified cellulose for later use; crushing and sieving 30g of modified wollastonite powder and 20g of modified cellulose, adding the crushed and sieved modified wollastonite powder and 20g of modified cellulose into 80g of deionized water, stirring for 30min, adding 4g of titanate, keeping the temperature and stirring for 50min, filtering and drying to obtain composite powder; adding 100g of ethylene-vinyl acetate copolymer, 40g of polyvinyl chloride resin and 14g of inorganic nanoparticles into 80g of deionized water, and uniformly mixing to obtain a mixed solution; and adding the composite powder into the mixed solution, adding 4g of magnesium stearate, keeping the temperature for 2h, cooling to room temperature, and adjusting the pH value to 7 to obtain the polymer cement concrete additive.

Example 5

Adding wollastonite powder into trifluoroethyl methacrylate, stirring at 50 ℃ for 3h, centrifuging for 0.5h, and then placing in a vacuum drying oven for drying for 14h at the drying temperature of 80 ℃ to obtain modified wollastonite powder for later use; adjusting the pH value of the cellulose to 7.5 by using a sodium hydroxide solution, then putting the cellulose into a dryer for drying, and grinding the cellulose into 60-mesh powder to obtain modified cellulose for later use; crushing and sieving 35g of modified wollastonite powder and 20g of modified cellulose, adding into 80g of deionized water, stirring for 30min, adding 4g of titanate, keeping the temperature, stirring for 50min, filtering and drying to obtain composite powder; adding 100g of ethylene-vinyl acetate copolymer, 40g of polyvinyl chloride resin and 14g of inorganic nanoparticles into 80g of deionized water, and uniformly mixing to obtain a mixed solution; and adding the composite powder into the mixed solution, adding 4g of magnesium stearate, keeping the temperature for 2h, cooling to room temperature, and adjusting the pH value to 7 to obtain the polymer cement concrete additive.

Example 6

Adding wollastonite powder into trifluoroethyl methacrylate, stirring at 50 ℃ for 3h, centrifuging for 0.5h, and then placing in a vacuum drying oven for drying for 14h at the drying temperature of 80 ℃ to obtain modified wollastonite powder for later use; adjusting the pH value of the cellulose to 7.5 by using a sodium hydroxide solution, then putting the cellulose into a dryer for drying, and grinding the cellulose into 60-mesh powder to obtain modified cellulose for later use; crushing and sieving 15g of modified wollastonite powder and 25g of modified cellulose, adding into 80g of deionized water, stirring for 30min, adding 4g of titanate, keeping the temperature, stirring for 50min, filtering and drying to obtain composite powder; adding 100g of ethylene-vinyl acetate copolymer, 40g of polyvinyl chloride resin and 14g of inorganic nanoparticles into 80g of deionized water, and uniformly mixing to obtain a mixed solution; and adding the composite powder into the mixed solution, adding 4g of magnesium stearate, keeping the temperature for 2h, cooling to room temperature, and adjusting the pH value to 7 to obtain the polymer cement concrete additive.

Example 7

Adding wollastonite powder into trifluoroethyl methacrylate, stirring at 50 ℃ for 3h, centrifuging for 0.5h, and then placing in a vacuum drying oven for drying for 14h at the drying temperature of 80 ℃ to obtain modified wollastonite powder for later use; adjusting the pH value of the cellulose to 7.5 by using a sodium hydroxide solution, then putting the cellulose into a dryer for drying, and grinding the cellulose into 60-mesh powder to obtain modified cellulose for later use; crushing and sieving 15g of modified wollastonite powder and 30g of modified cellulose, adding into 80g of deionized water, stirring for 30min, adding 4g of titanate, keeping the temperature, stirring for 50min, filtering and drying to obtain composite powder; adding 100g of ethylene-vinyl acetate copolymer, 40g of polyvinyl chloride resin and 14g of inorganic nanoparticles into 80g of deionized water, and uniformly mixing to obtain a mixed solution; and adding the composite powder into the mixed solution, adding 4g of magnesium stearate, keeping the temperature for 2h, cooling to room temperature, and adjusting the pH value to 7 to obtain the polymer cement concrete additive.

Example 8

Adding wollastonite powder into trifluoroethyl methacrylate, stirring at 50 ℃ for 3h, centrifuging for 0.5h, and then placing in a vacuum drying oven for drying for 14h at the drying temperature of 80 ℃ to obtain modified wollastonite powder for later use; adjusting the pH value of the cellulose to 7.5 by using a sodium hydroxide solution, then putting the cellulose into a dryer for drying, and grinding the cellulose into 60-mesh powder to obtain modified cellulose for later use; crushing and sieving 15g of modified wollastonite powder and 35g of modified cellulose, adding into 80g of deionized water, stirring for 30min, adding 4g of titanate, keeping the temperature, stirring for 50min, filtering and drying to obtain composite powder; adding 100g of ethylene-vinyl acetate copolymer, 40g of polyvinyl chloride resin and 14g of inorganic nanoparticles into 80g of deionized water, and uniformly mixing to obtain a mixed solution; and adding the composite powder into the mixed solution, adding 4g of magnesium stearate, keeping the temperature for 2h, cooling to room temperature, and adjusting the pH value to 7 to obtain the polymer cement concrete additive.

Example 9

Adding wollastonite powder into trifluoroethyl methacrylate, stirring at 50 ℃ for 3h, centrifuging for 0.5h, and then placing in a vacuum drying oven for drying for 14h at the drying temperature of 80 ℃ to obtain modified wollastonite powder for later use; adjusting the pH value of the cellulose to 7.5 by using a sodium hydroxide solution, then putting the cellulose into a dryer for drying, and grinding the cellulose into 60-mesh powder to obtain modified cellulose for later use; crushing and sieving 15g of modified wollastonite powder and 40g of modified cellulose, adding into 80g of deionized water, stirring for 30min, adding 4g of titanate, keeping the temperature, stirring for 50min, filtering and drying to obtain composite powder; adding 100g of ethylene-vinyl acetate copolymer, 40g of polyvinyl chloride resin and 14g of inorganic nanoparticles into 80g of deionized water, and uniformly mixing to obtain a mixed solution; and adding the composite powder into the mixed solution, adding 4g of magnesium stearate, keeping the temperature for 2h, cooling to room temperature, and adjusting the pH value to 7 to obtain the polymer cement concrete additive.

Example 10

Adding wollastonite powder into trifluoroethyl methacrylate, stirring at 50 ℃ for 3h, centrifuging for 0.5h, and then placing in a vacuum drying oven for drying for 14h at the drying temperature of 80 ℃ to obtain modified wollastonite powder for later use; adjusting the pH value of the cellulose to 7.5 by using a sodium hydroxide solution, then putting the cellulose into a dryer for drying, and grinding the cellulose into 60-mesh powder to obtain modified cellulose for later use; crushing and sieving 25g of modified wollastonite powder and 30g of modified cellulose, adding into 80g of deionized water, stirring for 30min, adding 4g of titanate, keeping the temperature, stirring for 50min, filtering and drying to obtain composite powder; adding 100g of ethylene-vinyl acetate copolymer, 40g of polyvinyl chloride resin and 14g of inorganic nanoparticles into 80g of deionized water, and uniformly mixing to obtain a mixed solution; and adding the composite powder into the mixed solution, adding 4g of magnesium stearate, keeping the temperature for 2h, cooling to room temperature, and adjusting the pH value to 7 to obtain the polymer cement concrete additive.

Control group

Taking a commercial common cement concrete additive.

The cement concrete additives in examples 1-10 and the control group were subjected to performance tests, which were as follows:

water retention property test: the method is characterized by referring to national standard building material industry standard JC 901-2002 'cement concrete additive' and traffic industry standard JT/T522-2004 'highway engineering concrete additive'.

Surface Water absorption test: according to standard ASTMC 1585-13 test method for measuring water absorption of hydraulic cement concrete, concrete is molded into a cube of 100mm multiplied by 100mm, the cube is taken out after curing to a corresponding age and dried at a low temperature of 60 ℃, 4 side faces are sealed with wax, and molding faces are left. And placing the weighed materials in water, taking out the materials after half an hour, weighing again, wherein the difference of the two times of weighing is the water absorption, and calculating the surface water absorption according to a formula.

And (3) testing the compressive strength: refer to JC 901-2002 Cement concrete additives and JT/T522-2004 Highway engineering concrete additives.

Specific data are shown in table 1:

TABLE 1

As can be seen from table 1, the cement concrete additive prepared according to the present invention has better water retention, surface water absorption and compressive strength than the commercially available ordinary cement concrete additive, wherein the cement concrete additive prepared in example 10 has the highest water retention, surface water absorption and compressive strength; according to the embodiments 1 to 5, when the amount of the modified wollastonite powder is 25g, the water retention rate, the surface water absorption rate and the compressive strength of the prepared cement concrete additive are highest; according to the examples 1 and 6 to 9, when the amount of the modified cellulose is 30g, the water retention rate, the surface water absorption rate and the compressive strength of the prepared cement concrete additive are highest.

Further, based on the preparation steps of example 10, the single-factor deletion comparative experiment was performed on the modified cellulose and the modified wollastonite powder, and the experimental results show that different factors are deleted, and the water retention rate, the surface water absorption rate and the compressive strength of the finally prepared cement concrete additive also have certain differences, which are shown in the following comparative examples.

Comparative example 1

Adjusting the pH value of the cellulose to 7.5 by using a sodium hydroxide solution, then putting the cellulose into a dryer for drying, and grinding the cellulose into 60-mesh powder to obtain modified cellulose for later use; crushing and sieving 30g of modified cellulose, adding 80g of deionized water, stirring for 30min, adding 4g of titanate, keeping the temperature, stirring for 50min, filtering and drying to obtain composite powder; adding 100g of ethylene-vinyl acetate copolymer, 40g of polyvinyl chloride resin and 14g of inorganic nanoparticles into 80g of deionized water, and uniformly mixing to obtain a mixed solution; and adding the composite powder into the mixed solution, adding 4g of magnesium stearate, keeping the temperature for 2h, cooling to room temperature, and adjusting the pH value to 7 to obtain the polymer cement concrete additive.

Comparative example 2

Adding wollastonite powder into trifluoroethyl methacrylate, stirring at 50 ℃ for 3h, centrifuging for 0.5h, and then placing in a vacuum drying oven for drying for 14h at the drying temperature of 80 ℃ to obtain modified wollastonite powder for later use; crushing and sieving 25g of modified wollastonite powder, adding the crushed modified wollastonite powder into 80g of deionized water, stirring for 30min, adding 4g of titanate, keeping the temperature, stirring for 50min, filtering and drying to obtain composite powder; adding 100g of ethylene-vinyl acetate copolymer, 40g of polyvinyl chloride resin and 14g of inorganic nanoparticles into 80g of deionized water, and uniformly mixing to obtain a mixed solution; and adding the composite powder into the mixed solution, adding 4g of magnesium stearate, keeping the temperature for 2h, cooling to room temperature, and adjusting the pH value to 7 to obtain the polymer cement concrete additive.

Comparative example 3

Adding 100g of ethylene-vinyl acetate copolymer, 40g of polyvinyl chloride resin and 14g of inorganic nanoparticles into 80g of deionized water, and uniformly mixing to obtain a mixed solution; adding 4g of magnesium stearate, keeping the temperature for 2h, cooling to room temperature, and adjusting the pH value to 7 to obtain the polymer cement concrete additive.

And (3) carrying out performance test on the cement concrete additive in the comparative examples 1-3, wherein the specific test is as follows:

And (3) testing the compressive strength: refer to JC 901-2002 Cement concrete additives and JT/T522-2004 Highway engineering concrete additives.

Specific data are shown in table 2:

TABLE 2

As can be seen from Table 2, the water retention rate, the surface water absorption and the compressive strength of the polymer cement concrete additive prepared by the method are greatly improved compared with the single use of the modified cellulose and the single use of the modified wollastonite powder.

In general, the invention improves the water retention property of the additive by modifying the cellulose, increasing the number of hydrophilic amino groups on the surface of the cellulose and improving the water retention property of the fiber and adding the modified cellulose into the base material of the concrete additive; meanwhile, the wollastonite powder is modified by utilizing trifluoroethyl methacrylate, so that fluorine atoms with high fluorine electronegativity surround carbon chains to form a spiral structure, a hydrophobic effect is achieved, the carbon bonds are protected from being easily damaged by chemical media, a hydroxyl group can be utilized to perform a chemical bonding effect with silicon atoms on the surface of concrete, the bonding force of an additive and the surface of the concrete is enhanced, the surface is more compact, the compact maintenance film effectively prevents the evaporation of water on the surface of the concrete, and the water retention effect is improved.

It should be understood that the above-mentioned embodiments are only preferred embodiments of the present invention, and are not intended to limit the present invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

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