阅读说明：本技术 一种固废生态混凝土及其制备方法 (Solid waste ecological concrete and preparation method thereof ) 是由 黄臣 李伟 石鑫 刘坤 潘航 武李杰 于 2021-08-18 设计创作，主要内容包括：本发明公开一种固废生态混凝土及其制备方法,涉及建筑材料领域,包括以下重量份数的组分：水泥225-315份、粗骨料1720份、水90份、矿物掺合料135-225份、减水剂2份、短切聚酯基竹炭纤维2-6份,粗骨料包括碎石与再生粗骨料,碎石与再生粗骨料粒径为5-30mm,碎石与再生粗骨料的重量比为(1：0.3-3)；矿物掺合料由矿渣微粉与粉煤灰组成,矿渣微粉、粉煤灰与水泥的质量比为1：1：(2-4)。通过再生粗骨料与碎石的特定比例搭配以及粒径的设置,在实现固废的同时也保证了所制备的生态混凝土拥有良的强度与较大的孔隙率,同时在混凝土原料中添加了矿物掺合料以及短切聚酯基竹炭纤维用于进一步提高生态混凝土的强度,以此进一步减小再生粗骨料对生态混凝土强度的影响。(The invention discloses solid waste ecological concrete and a preparation method thereof, which relate to the field of building materials and comprise the following components in parts by weight: 315 parts of cement 225-containing materials, 1720 parts of coarse aggregates, 90 parts of water, 135-containing materials of mineral admixtures, 2 parts of water reducing agents and 2-6 parts of short-cut polyester-based bamboo charcoal fibers, wherein the coarse aggregates comprise crushed stone and regenerated coarse aggregates, the particle size of the crushed stone and the regenerated coarse aggregates is 5-30mm, and the weight ratio of the crushed stone to the regenerated coarse aggregates is (1: 0.3-3); the mineral admixture is composed of slag micropowder and fly ash, and the mass ratio of the slag micropowder, the fly ash and the cement is 1: 1: (2-4). Through the specific proportion collocation of the recycled coarse aggregate and the broken stone and the setting of the particle size, the prepared ecological concrete has good strength and larger porosity while realizing solid waste, and simultaneously, the mineral admixture and the chopped polyester-based bamboo charcoal fiber are added into the concrete raw material for further improving the strength of the ecological concrete, thereby further reducing the influence of the recycled coarse aggregate on the strength of the ecological concrete.)

1. The solid waste ecological concrete is characterized by comprising the following components in parts by weight: 315 parts of cement 225-containing materials, 1720 parts of coarse aggregates, 90 parts of water, 135-containing materials of mineral admixtures, 2 parts of water reducing agents and 2-6 parts of short-cut polyester-based bamboo charcoal fibers, wherein the coarse aggregates comprise crushed stone and regenerated coarse aggregates, the particle size of the crushed stone and the regenerated coarse aggregates is 5-30mm, and the weight ratio of the crushed stone to the regenerated coarse aggregates is (1: 0.3-3); the mineral admixture is composed of slag micropowder and fly ash, and the mass ratio of the slag micropowder to the fly ash to the cement is 1: 1: (2-4), the recycled coarse aggregate is made of waste concrete.

2. The solid waste ecological concrete according to claim 1, which comprises the following components in parts by weight: the weight of the cement is 270 parts, the coarse aggregate 1720 parts, the water is 90 parts, the mineral admixture 135-225 parts, the water reducing agent 2 parts and the chopped polyester-based bamboo charcoal fiber 4 parts.

3. The solid waste ecological concrete according to claim 2, wherein the weight ratio of the fly ash, the slag micropowder and the cement is 1: 1: 3.

4. the solid waste ecological concrete according to claim 3, wherein the particle size of the crushed stone and the recycled coarse aggregate is 10-25mm, and the mass ratio of the crushed stone to the recycled coarse aggregate is (1: 1).

5. The solid waste ecological concrete according to any one of claims 1 to 4, wherein the water reducing agent is a polycarboxylic acid high efficiency water reducing agent.

6. The preparation method of the solid waste ecological concrete in claim 1 comprises the following steps: the method is characterized in that cement, fly ash, slag micro powder and a water reducing agent are added into a stirrer and stirred for 1min, then short-cut polyester-based bamboo charcoal fiber is added and stirred for 2min, then water is added and stirred until all materials are uniformly distributed in slurry, then half of coarse aggregate is added and stirred for 0.5min, and finally the other half of coarse aggregate is added and stirred for 0.5min, so that the solid waste ecological concrete is obtained.

Technical Field

The invention relates to the field of building materials, in particular to solid waste ecological concrete and a preparation method thereof.

Background

The ecological concrete, cast-in-situ plant growing type ecological concrete (large aggregate non-sand concrete) is a novel ecological concrete slope protection technology which is used for controlling and protecting hydraulic engineering side slopes (such as waterfront zones, river channels, dams, reservoirs and the like) and considering environmental factors. The porous concrete is prepared by mixing coarse aggregate of continuous grain size fraction and a certain amount of fine aggregate according to a certain proportion range (the fine aggregate is not needed if necessary), then stirring, pouring and naturally curing, and then the porous concrete with a popped rice sugar-shaped surface and a large amount of communicated and fine pores is obtained. Its main feature is that there are lots of independent or continuous pores, and it possesses several functions which are not possessed by general concrete and ordinary ecological concrete. Therefore, the concrete not only has wide attention in the concrete field, but also has great application potential value in a plurality of fields such as ecological and environmental protection.

Along with the rapid development of economy and the accelerated urbanization construction process in China, a large amount of construction waste is generated by dismantling old buildings, the natural environment which people rely on for survival is seriously polluted, and the effective treatment and the cyclic utilization of the construction waste become environmental and social problems to be solved urgently, so that the preparation of the recycled coarse aggregate by utilizing the waste concrete blocks in the construction waste is an important way for solving the current problems, the recycled coarse aggregate can also be applied to ecological concrete, but the recycled coarse aggregate has the problem of low strength, the problem of short service life and safety can exist when being directly used for preparing the ecological concrete, the porosity of the ecological concrete is an important index for representing the water and air permeability of the ecological concrete, the large porosity is also beneficial to the growth of plants, and the compressive strength and the porosity in the ecological concrete generally have an inverse proportion relation, so how to keep the porosity of the ecological concrete, but also can improve the strength of the steel is a problem to be solved urgently.

In the prior art, for example, the invention with the application number of CN201811300090.0 discloses a water-purifying ecological concrete, which comprises 15 to 25 parts of cement, 0.45 to 0.65 part of reinforcing material, 0 to 0.3 part of latex powder, 1 to 4 parts of water-purifying material, 5 to 10 parts of water-purifying particles, 65 to 75 parts of aggregate and 0.05 to 0.15 part of water-reducing agent, wherein the water-purifying particles comprise particles with a purifying function and a starch film positioned on the outer surface of the particles with the purifying function, the starch film is formed by spraying a starch film solution with the mass fraction of 5 to 15 percent on the outer surface of the particles with the purifying function and then drying the starch film solution, and the starch film solution is obtained by dissolving modified starch in a solvent; the solvent is 1, 4-dioxane, dichloromethane, trichloromethane or acetone; the modified starch is obtained by esterification modification of corn starch, potato starch or tapioca starch.

According to the prior art, the water purifying capacity of the ecological concrete is improved by adding the water purifying material into the raw materials, but the waste concrete blocks cannot be applied to the ecological concrete, and the used materials do not belong to regenerated materials, so that the defects of insufficient resource saving and no treatment effect on the ecological environment exist.

Disclosure of Invention

The invention discloses solid waste ecological concrete, aiming at the problem that a regenerative material is difficult to apply to ecological concrete. Specifically, the following technique is used.

The solid waste ecological concrete comprises the following components in parts by weight: 315 parts of cement 225-containing materials, 1720 parts of coarse aggregates, 90 parts of water, 135-containing materials of mineral admixtures, 2 parts of water reducing agents and 2-6 parts of short-cut polyester-based bamboo charcoal fibers, wherein the coarse aggregates comprise crushed stone and regenerated coarse aggregates, the particle size of the crushed stone and the regenerated coarse aggregates is 5-30mm, and the weight ratio of the crushed stone to the regenerated coarse aggregates is (1: 0.3-3); the mineral admixture is composed of slag micropowder and fly ash, and the mass ratio of the slag micropowder to the fly ash to the cement is 1: 1: (2-4), the recycled coarse aggregate is made of waste concrete.

According to the solid waste ecological concrete provided by the invention, the concrete waste is used as the recycled coarse aggregate, and the slag micro-ingredients and the fly ash waste are recycled to prepare the ecological concrete, so that the effect of solid waste is achieved; the specific grading arrangement of the broken stones and the recycled coarse aggregate ensures that the compressive strength of the ecological concrete can be ensured when the ecological concrete has higher porosity; meanwhile, the mineral admixture and the chopped polyester-based bamboo charcoal fiber are added into the concrete raw material to further improve the strength of the ecological concrete, so that the influence of the regenerated coarse aggregate on the strength of the ecological concrete is further reduced. .

Preferably, the composition comprises the following components in parts by weight: the weight of the cement is 270 parts, the coarse aggregate 1720 parts, the water is 90 parts, the mineral admixture 135-225 parts, the water reducing agent 2 parts and the chopped polyester-based bamboo charcoal fiber 4 parts.

Preferably, the weight ratio of the fly ash, the slag micro powder and the cement is 1: 1: 3.

preferably, the particle size of the crushed stone and the recycled coarse aggregate is 10-25mm, and the mass ratio of the crushed stone to the recycled coarse aggregate is (1: 1).

The adoption of 10-25mm graded coarse aggregate can improve the compressive strength of the concrete and ensure the porosity of the ecological concrete.

Preferably, the water reducing agent is a polycarboxylic acid high-efficiency water reducing agent.

More preferably, the preparation method of the solid waste ecological concrete specifically comprises the following steps: adding cement, fly ash, slag micro powder and a water reducing agent into a stirrer, stirring for 1min, adding the chopped polyester-based bamboo charcoal fiber, stirring for 2min, adding water, stirring until the materials are uniformly distributed in the slurry, adding half of coarse aggregate, stirring for 0.5min, adding the other half of coarse aggregate, and stirring for 0.5min to obtain the solid waste ecological concrete.

Compared with the prior art, the invention has the advantages that:

1. according to the invention, the regenerative coarse aggregate and the mineral admixture are added into the raw materials of the ecological concrete, so that the effect of waste solidification is achieved, and meanwhile, the short-cut polyester-based bamboo charcoal fiber is added, so that the ecological concrete promotes the mechanical property of the ecological concrete under the synergistic effect of the short-cut polyester-based bamboo charcoal fiber and the mineral admixture, and meanwhile, the porosity of the ecological concrete is kept, so that the ecological concrete has good air permeability and water permeability, and the ecological concrete is beneficial to the growth of plants.

2. According to the invention, the ecological concrete has certain porosity and high strength at the same time by setting the mass ratio of the broken stones to the recycled coarse aggregate in the coarse aggregate and the special grading particle size.

3. The invention enhances the mechanical property of the ecological concrete by adding the short polyester-based bamboo charcoal fiber and can purify water to a certain extent.

Detailed Description

The technical solutions of the present invention will be described clearly and completely below, 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 derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The ecological concrete test pieces used in the following examples and comparative examples were prepared by the following methods:

firstly adding cement, fly ash, slag micro powder and a water reducing agent into a stirrer, stirring for 1min, then adding the chopped polyester-based bamboo charcoal fiber, stirring for 2min, then adding water, stirring until all materials are uniformly distributed in slurry, then adding half of coarse aggregate, stirring for 0.5min, and finally adding the other half of coarse aggregate, stirring for 0.5min to obtain a concrete mixture; the mixture is shaped by inserting and tamping, and the concrete inserting and tamping steps are as follows:

the concrete mixture should be loaded into the mold in two layers, and the loading thickness of each layer is approximately equal.

The insertion and tamping are uniformly performed from the edge to the center in the spiral direction. When bottom concrete is inserted and tamped, the tamping bar is required to reach the bottom of the test mold; the inserting and tamping should penetrate through the upper layer and then enter the lower layer for 20-30 mm; during tamping, the tamping rod is kept vertical and is not inclined, and then the spatula is used for inserting and pulling along the inner wall of the mold for a plurality of times.

Each layer of the threeNumber of tamping is 10000mm²The cross-sectional area is not less than 12 times.

After the inserting and smashing, the periphery is lightly knocked by using a rubber hammer until a cavity left by the inserting and smashing rod disappears.

And fifthly, scraping the excessive concrete on the upper opening of the test mold, and trowelling the concrete when the concrete is close to initial setting.

The cement, the slag micropowder, the fly ash, the recycled coarse aggregate and the chopped polyester-based bamboo charcoal fiber used in the following examples and comparative examples all adopt the following products:

the cement is a commercial P.O42.5 cement.

The slag micro powder is commercially available S95 grade blast furnace slag micro powder.

The fly ash is purchased from Hubei and has grade II.

The chopped polyester-based bamboo charcoal fiber is purchased from Yun Rui chemical fiber Co., Ltd.

The recycled coarse aggregate is a commercial recycled concrete coarse aggregate.

Example 1

The solid waste ecological concrete prepared by the invention comprises the following components in parts by weight: 270 parts of cement, 1720 parts of coarse aggregate, 90 parts of water, 180 parts of mineral admixture, 2 parts of polycarboxylic acid high-efficiency water reducing agent and 4 parts of chopped polyester-based bamboo charcoal fiber, wherein the coarse aggregate comprises crushed stone and regenerated coarse aggregate, and the weight ratio of the crushed stone to the regenerated coarse aggregate is (1: 1); the particle size of the crushed stone and the recycled coarse aggregate is 10-25 mm; the weight ratio of the fly ash to the slag micro powder to the cement is 1: 1: 3.

example 2

The preparation method and raw materials of the solid waste ecological concrete provided by the embodiment are the same as those of the embodiment 1.

Except that the weight ratio of the crushed stone to the recycled coarse aggregate is (1: 0.3).

Example 3

The preparation method and raw materials of the solid waste ecological concrete provided by the embodiment are the same as those of the embodiment 1.

Except that the weight ratio of the crushed stone to the recycled coarse aggregate is (1: 3).

Example 4

The preparation method and raw materials of the solid waste ecological concrete provided by the embodiment are the same as those of the embodiment 1.

The difference is that the particle size of the crushed stone and the recycled coarse aggregate is 5-30 mm.

Example 5

The preparation method and raw materials of the solid waste ecological concrete provided by the embodiment are the same as those of the embodiment 1.

The difference is that the cement accounts for 315 parts by weight, the mineral admixture accounts for 135 parts by weight, and the weight ratio of the fly ash to the slag micropowder is 1: 1: 4.

example 6

The preparation method and raw materials of the solid waste ecological concrete provided by the embodiment are the same as those of the embodiment 1.

Except that the weight portion of the chopped polyester-based bamboo charcoal fiber is 6 portions.

Example 7

The preparation method and raw materials of the solid waste ecological concrete provided by the embodiment are the same as those of the embodiment 1.

Except that the weight portion of the chopped polyester-based bamboo charcoal fiber is 2 portions.

Example 8

The preparation method and raw materials of the solid waste ecological concrete provided by the embodiment are the same as those of the embodiment 1.

The difference is that the cement is 225 parts by weight, the fly ash and the slag micropowder are 1: 1: 2.

comparative example 1

The preparation method and raw materials of the solid waste ecological concrete provided by the comparative example are the same as those in example 1.

The difference is that the solid waste concrete comprises the following components in parts by weight: 450 parts of cement, 1720 parts of recycled coarse aggregate, 90 parts of water and 2 parts of polycarboxylic acid high-efficiency water reducing agent with crushed stone particle size of 5-30 mm. Namely mineral admixture, chopped polyester-based bamboo charcoal fiber and macadam are not included.

Comparative example 2

The preparation method and raw materials of the solid waste ecological concrete provided by the comparative example are the same as those in example 1.

The difference is that the raw material composition of the solid waste concrete does not comprise mineral admixture.

Comparative example 3

The preparation method and raw materials of the solid waste ecological concrete provided by the comparative example are the same as those in example 1.

Except that the mineral admixture only comprises 180 parts by weight of fly ash.

Comparative example 4

The preparation method and raw materials of the solid waste ecological concrete provided by the comparative example are the same as those in example 1.

The difference is that the mineral admixture only contains 180 parts by weight of slag micropowder.

Comparative example 5

The preparation method and raw materials of the solid waste ecological concrete provided by the comparative example are the same as those in example 1.

The difference is that the raw material composition of the solid waste concrete does not comprise the chopped polyester-based bamboo charcoal fiber.

Experimental example: performance test of solid waste ecological concrete

1. Determination of porosity

Firstly, measuring the volume of the test block, completely immersing the test block in a container filled with water, collecting the water discharged from the container, measuring the volume of the discharged water, and subtracting the ratio of the volume of the discharged water to the volume of the test block by 1 to obtain the porosity.

2. Strength testing of concrete

And (3) detecting the compressive strength of the solid waste ecological concrete after being cured for 28 days according to the concrete physical property test method standard (GB/T50081-2019).

TABLE 1 Performance test Table for solid waste ecological concrete

As can be seen from the above table, in the raw materials of the ecological concrete, the particle size of the coarse aggregate has a great influence on the porosity, and if the coarse aggregate with the particle size of 5-30mm is selected to prepare the ecological concrete, although the stacking density of the concrete is improved, so that the compressive strength of the concrete is improved, the porosity is also greatly reduced; when the coarse aggregate with the grain diameter of 10-25mm is selected to prepare the ecological concrete, the contact surface between the aggregates is increased, the compressive strength of the concrete is improved, the coarse aggregate with small grain diameter is not filled between the coarse aggregates with large grain diameter, and the porosity of the ecological concrete can be kept at a higher level while the compressive strength of the ecological concrete is ensured.

As can be seen from the data of comparative example 1, as the recycled coarse aggregates are all formed by mechanical crushing, cracks are contained on the surface or inside of the recycled coarse aggregates, the compressive strength is low, and if the formula of the ecological concrete is not treated, the natural coarse aggregates in the original raw materials of the ecological concrete are directly replaced by the recycled coarse aggregates, so that the compressive strength of the ecological concrete is extremely low, and even potential safety hazards exist; the problems can be well solved by adding the fly ash, the slag micro powder and the short-cut polyester-based bamboo charcoal fiber, the slag micro powder can effectively improve the compressive strength of the ecological concrete, the bamboo charcoal particles in the short-cut polyester-based bamboo charcoal fiber are embedded in the polymer aggregate and form protrusions on the surface of the bamboo charcoal fiber, and the surface of the bamboo charcoal particle is of a porous structure, so that the friction force between the bamboo charcoal particle and an ecological concrete matrix can be effectively increased, a good bridging effect is achieved, and the bonding force between the ecological concrete matrix is stronger; the fly ash can enhance the fluidity of concrete slurry, so that raw material components in the concrete are uniformly dispersed, and the overall performance of the ecological concrete can be improved by the components. According to the invention, through the combined action of the fly ash, the slag micro powder and the short-cut polyester-based bamboo charcoal fiber, the problem of low compressive strength of the recycled coarse aggregate is solved, so that the recycled coarse aggregate can be more applied to ecological concrete, resources are recycled, and the damage of concrete waste to the environment is reduced.