CN103771782A - Porous concrete prepared from waste concrete aggregate and preparation method thereof - Google Patents

Abstract

The invention discloses porous concrete prepared from waste concrete aggregate and a preparation method thereof. The porous concrete comprises 1-4 parts of polypropylene fiber, 250-300 parts of cement, 1200-1500 parts of recycled aggregate, 130-160 parts of sand, 90-110 parts of water, and 3-6 parts of admixture, wherein the admixture comprises 20-25 parts of a polycarboxylate superplasticizer, 10-15 parts of ferric sulfate, 10-15 parts of limestone powder and 50-60 parts of active silica solid particles. The preparation method comprises the following steps: firstly preparing the recycled aggregate of waste concrete, then mixing and stirring the polypropylene fiber, the cement, the recycled aggregate, the water and the admixture according to a mixture ratio, and uniformly stirring the mixture within corresponding time, thus obtaining the porous concrete. The waste concrete can be recycled and serves as the aggregate for preparing the porous concrete; meanwhile, the strength of the prepared porous concrete is improved, and the pH value is reduced, so that the normal use of the porous concrete in architectural engineering is ensured.

Description

Cellular concrete and method thereof prepared by a kind of discarded concrete aggregate

Technical field

The present invention relates to cellular concrete and method thereof prepared by a kind of discarded concrete aggregate, belong to concrete technology field.

Background technology

Cellular concrete is a kind of concrete with special hole gap structure, is made up through special process of the gathering materials of specific grating, cement, water, admixture etc.Ventilative, the water permeability of cellular concrete excellence, make the positions such as its road both sides, river course slope protection, roof and parking lot that is widely used in city, play and improve damp and hot exchange capacity, reduce concrete material surface temperature, increase the vert space in city, safeguard the active effect of the urban climate eubiosis.

Along with China's Economic development, Process of Urbanization Construction deepens continuously, and the foundation of new building and the dismounting of old building have produced a large amount of building wastes, is mainly wherein discarded concrete.Traditional treatment process is landfill or stacking, has not only consumed a large amount of costs of erection such as arable land and refuse collection, and has caused very large pressure to environmental improvement.

When aggregate using discarded concrete as cellular concrete, often have the problem that aggregate intensity is low, water-intake rate is large, directly utilization can cause cellular concrete low strength, shrink the problems such as large, affects the application of engineering.How to be a urgent problem by discarded concrete recycling treatment.

Summary of the invention

The problem existing for above-mentioned prior art, the invention provides cellular concrete and method thereof prepared by a kind of discarded concrete aggregate, discarded concrete can be recycled and prepared cellular concrete as aggregate, improve the intensity of the cellular concrete after preparation simultaneously and reduce pH value, thereby guaranteeing that construction work is normally used.

To achieve these goals, the technical solution used in the present invention is: cellular concrete prepared by this discarded concrete aggregate, concrete component and quality proportioning are: 3～6 parts of 1～4 part of polypropylene fibre, 250～300 parts of cement, 1200～1500 parts of regeneration aggregates, sand 130-160 part, 90～110 parts, water and admixtures, described admixture is by 20～25 parts of polycarboxylate water-reducers, 10～15 parts, ferric sulfate, 10～15 parts of Wingdale powders, 50～60 parts of compositions of active silica solid particulate.

Discarded concrete aggregate is prepared a method for cellular concrete, and concrete steps are:

(1) roughly select and adopt reaction type breaking method smashing waste concrete, adopt the sieve screening of grating 5～20 or grating 20～40 to obtain discarded concrete aggregate;

(2) the discarded concrete aggregate that adopts the silica flour slurries soaking step (1) of concentration 8%-10% to obtain, and constantly stirring, for several times after, in the time of liquid initial set, aggregate is taken out, put in standard curing room maintenance 28 days;

(3) regeneration aggregate, water and the admixture that polypropylene fibre, cement, step (2) are obtained, according to proportioning, successively the regeneration aggregate of 1/2 part, whole sands, whole cement, the regeneration aggregate of remaining 1/2 part and whole polypropylene fibre orders are added in container, the pre-25s that stirs, then adds 1/2 part of water of proportioning to stir 60s formation compound I;

(4) in compound I, add the admixture of proportioning and 1/2 part of water of proportioning to mix, stir 180s, form compound II, after completing, can start discharging.

Compared with prior art, the present invention as regeneration aggregate, has solved the recycling of discarded concrete after discarded concrete is processed; Add polypropylene fibre and admixture simultaneously, thereby make the cellular concrete of preparation, there is higher tension and beaming resistance limit intensity, good toughness, can be on parking lot, square etc. light-duty pavement usage; Reduce in addition the internal pH-values of cellular concrete due to the interpolation of admixture, provide plant at the required environment of hole growth inside, can be applicable to the ground such as counterfort virescence and slope, roadside.

Accompanying drawing explanation

Fig. 1 is the stirring technique figure of cellular concrete in the present invention.

Embodiment

Below in conjunction with accompanying drawing, the invention will be further described.

Cellular concrete prepared by this discarded concrete aggregate, concrete component and quality proportioning are: 3～6 parts of 1～4 part of polypropylene fibre, 250～300 parts of cement, 1200～1500 parts of regeneration aggregates, sand 130-160 part, 90～110 parts, water and admixtures, described admixture is by 20～25 parts of polycarboxylate water-reducers, 10～15 parts, ferric sulfate, 10～15 parts of Wingdale powders, 50～60 parts of compositions of active silica solid particulate.

As shown in Figure 1, this discarded concrete aggregate is prepared the method for cellular concrete, and concrete steps are:

(1) roughly select and adopt reaction type breaking method smashing waste concrete, adopt the sieve screening of grating 5～20 or grating 20～40 to obtain discarded concrete aggregate;

(2) the discarded concrete aggregate that adopts the silica flour slurries soaking step (1) of concentration 8%-10% to obtain, and constantly stirring, for several times after, in the time of liquid initial set, aggregate is taken out, put in standard curing room maintenance 28 days;

(3) regeneration aggregate, water and the admixture that polypropylene fibre, cement, step (2) are obtained, according to proportioning, successively the regeneration aggregate of 1/2 part, whole sands, whole cement, the regeneration aggregate of remaining 1/2 part and whole polypropylene fibre orders are added in container, the pre-25s that stirs, then adds 1/2 part of water of proportioning to stir 60s formation compound I;

(4) in compound I, add the admixture of proportioning and 1/2 part of water of proportioning to mix, stir 180s, form compound II, after completing, can start discharging.

Experimental data:

According to the cellular concrete in above-mentioned preparation method's Preparation Example;

Embodiment 1

Cement 260kg, sand 180kg, grating 5-20 regeneration aggregate 1300kg, polypropylene fibre 1.2kg, water 92kg, admixture 3.5kg.Label A.

Embodiment 2

Cement 270kg, sand 175kg, grating 5-20 regeneration aggregate 1350kg, polypropylene fibre 1.5kg, water 95kg, admixture 3.8kg.Label B.

Embodiment 3

Cement 280kg, sand 190kg, grating 5-20 regeneration aggregate 1400kg, polypropylene fibre 1.8kg, water 99kg, admixture 4.0kg.Label C.

Embodiment 4

Cement 300kg, sand 180kg, grating 20-40 regeneration aggregate 1420kg, polypropylene fibre 2.4kg, water 104kg, admixture 4.6kg.Label D.

Embodiment 5

Cement 285kg, sand 170kg, grating 20-40 regeneration aggregate 1380kg, polypropylene fibre 2.1kg, water 95kg, admixture 3.4kg.Label E.

Embodiment 6

Cement 255kg, sand 175kg, grating 20-40 regeneration aggregate 1330kg, polypropylene fibre 1.8kg, water 90kg, admixture 3.1kg.Label F.

Test respectively coefficient of permeability, ultimate compression strength and the folding strength etc. of cellular concrete A, B, C, D, E, F and evaluate cellular concrete index provided by the invention, as shown in table 1:

Table 1 embodiment results of property

Note: what numbering A-C cellular concrete mainly met is water permeability, intensity index, to the no requirement (NR) of pH value.What numbering D-F cellular concrete mainly met is to plant natural disposition energy, and general requirement has certain ultimate compression strength, and pH value will meet the needs of plant-growth simultaneously.

Adopt as can be seen from Table 1 the indices of cellular concrete prepared by discarded concrete all can meet industry standard, meet national regulation, therefore can normally use.

Claims (2)

1. a cellular concrete prepared by discarded concrete aggregate, it is characterized in that, concrete component and quality proportioning are: 3～6 parts of 1～4 part of polypropylene fibre, 250～300 parts of cement, 1200～1500 parts of regeneration aggregates, sand 130-160 part, 90～110 parts, water and admixtures, described admixture is by 20～25 parts of polycarboxylate water-reducers, 10～15 parts, ferric sulfate, 10～15 parts of Wingdale powders, 50～60 parts of compositions of active silica solid particulate.

2. discarded concrete aggregate is prepared a method for cellular concrete, it is characterized in that, concrete steps are:

(1) roughly select and adopt reaction type breaking method smashing waste concrete, adopt the sieve screening of grating 5～20 or grating 20～40 to obtain discarded concrete aggregate;

(2) the discarded concrete aggregate that adopts the silica flour slurries soaking step (1) of concentration 8%-10% to obtain, and constantly stirring, for several times after, in the time of liquid initial set, aggregate is taken out, put in standard curing room maintenance 28 days;

(3) regeneration aggregate, water and the admixture that polypropylene fibre, cement, step (2) are obtained, according to proportioning, successively the regeneration aggregate of 1/2 part, whole sands, whole cement, the regeneration aggregate of remaining 1/2 part and whole polypropylene fibre orders are added in container, the pre-25s that stirs, then adds 1/2 part of water of proportioning to stir 60s formation compound I;

(4) in compound I, add the admixture of proportioning and 1/2 part of water of proportioning to mix, stir 180s, form compound II, after completing, can start discharging.

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