阅读说明：本技术 一种建筑废弃垃圾再生集料颗粒复合强化方法 (Composite strengthening method for building waste regenerated aggregate particles ) 是由 胡靖� 娄宁 戴文龙 钱振东 罗桑 于 2021-08-31 设计创作，主要内容包括：本发明公开了一种建筑废弃垃圾再生集料颗粒复合强化方法,该方法选用成本低廉的材料作为强化剂,首先通过物理磨耗去除再生集料颗粒表面薄弱浮浆,其次采用纳米渗透型防水剂对再生集料颗粒表面进行预处理并养生,最后喷洒一定浓度的高弹性防水涂料。通过复合强化可有效封堵再生集料水泥砂浆的孔隙,显著改善再生集料颗粒的压碎值、粘附性与吸水率,其沥青混合料的力学性能接近甚至超过采用天然矿质集料的结构,具有成本低廉且效果好的优势。(The invention discloses a composite strengthening method for building waste regenerated aggregate particles, which selects a material with low cost as a strengthening agent, removes weak floating slurry on the surfaces of the regenerated aggregate particles through physical abrasion, pretreats the surfaces of the regenerated aggregate particles by adopting a nano permeable waterproofing agent, preserves the surfaces, and sprays high-elasticity waterproof coating with certain concentration. The composite reinforcement can effectively block the pores of the regenerated aggregate cement mortar, remarkably improve the crushing value, the adhesiveness and the water absorption of regenerated aggregate particles, has the mechanical property of the asphalt mixture close to or even surpass that of a structure adopting natural mineral aggregate, and has the advantages of low cost and good effect.)

1. The composite strengthening method of the building waste regenerated aggregate particles is characterized by comprising the following specific steps:

(1) the regenerated aggregate particles crushed by the construction waste are screened by a square hole screen to reserve the regenerated aggregate particles with the particle size of more than 2.35 mm;

(2) placing the screened and reserved regenerated aggregate particles into a los Angeles abrasion tester, and sieving the abraded regenerated aggregate particles again through a square-hole screen with the particle size of 2.35mm after the operation of a roller without placing a steel ball;

(3) spraying a nano permeable waterproofing agent on the surfaces of the regenerated aggregate particles obtained in the step (2) to wrap the particles, and drying the treated regenerated aggregate particles to obtain a pretreated regenerated aggregate;

(4) spraying high-elasticity waterproof paint on the pretreated regenerated aggregate particles, and drying the treated regenerated aggregate particles to obtain the composite reinforced regenerated aggregate particles.

2. The composite reinforcing method for the building waste regenerated aggregate particles according to claim 1, wherein a square-hole sieve is adopted in the sieving in the step (1) and the sieving in the step (2).

3. The composite strengthening method for the recycled aggregate particles of the construction waste according to claim 1, wherein the recycled aggregate particles in the step (1) are prepared by crushing cement concrete construction waste, mainly comprise old mineral particles and cement mortar wrapped by the old mineral particles, and the recycled aggregate particles with the particle size range of 2.35 mm-19 mm are retained by a square hole sieve.

4. The composite strengthening method for the recycled aggregate particles of the construction waste garbage according to claim 1, wherein in the step (2), the recycled aggregate particles are placed in a los Angeles abrasion tester according to the mass of 20 kg/part, steel balls are not required to be placed, the rotating speed is controlled to be 100r/min, the recycled aggregate particles are sieved again after running for 5 minutes, weak cement laitance on the surfaces of the particles is removed through mutual collision and friction of particle bodies, the particles with the particle size of 2.35 mm-19 mm are reserved, and the particles are washed and then placed outdoors for drying.

5. The composite strengthening method for the regenerated aggregate particles of the construction waste according to claim 1, wherein the nano permeable waterproofing agent in the step (3) is an organosilicon nano permeable waterproofing agent, and the amount of the nano permeable waterproofing agent is 5-6% of the mass of the regenerated aggregate particles.

6. The composite strengthening method for the building waste regenerated aggregate particles according to claim 1, wherein the high-elasticity waterproof coating in the step (4) is acrylic emulsion high-elasticity waterproof coating.

7. The composite strengthening method of the building waste regenerated aggregate particles according to claim 1, wherein the spraying amount of the high-elasticity waterproof coating in the step (4) is 5-6% of the mass of the regenerated aggregate particles.

8. The composite reinforcing method of the building waste regenerated aggregate particles according to claim 1, wherein the temperature for drying in the step (4) is 60 ℃.

Technical Field

The invention relates to a composite strengthening technology of regenerated aggregate particles, belonging to the technical field of regeneration and utilization of solid waste materials in road structures.

Background

At present, with the continuous improvement of the urbanization progress level in China, the continuous updating of infrastructures such as buildings and the like can lead to the generation of massive construction waste. The increasing of construction waste, the shortage of refuse landfill and the simplification of treatment modes bring serious problems of living environment pollution to the society. Aiming at the recycling of construction waste, particularly waste concrete construction waste, on one hand, the treatment mode of environmental damage caused by landfill, stacking and the like can be effectively relieved; on the other hand, the method also provides a huge raw material source for the infrastructure of traffic buildings and the like.

The regenerated aggregate obtained by demolishing and crushing the waste concrete building is a composite structural material and mainly comprises old aggregate and wrapped cement mortar. The basic physical mechanical properties and self-strength of the recycled aggregate are inferior to those of natural mineral aggregate due to the mortar wrapped by the recycled aggregate and the existence of numerous micro cracks and pores on the surface, such as lower density, higher water absorption rate, crushing value and abrasion value of the recycled aggregate. At present, the modification and reinforcement of the recycled aggregate are mainly divided into two types at home and abroad: one is to remove the mortar particles by mechanical grinding, high temperature heating, microwave de-sizing; the other type is to strengthen the regenerated aggregate by chemical reaction and pore and crack blocking through polymer, cement slurry and biological deposition. However, most modification treatment methods are not suitable for practical application due to the restriction of factors such as complicated process, high price and the like.

Disclosure of Invention

The technical problem is as follows: the invention aims to solve the technical defects and provides a composite strengthening method for building waste regenerated aggregate particles, which effectively reduces the porosity of mortar wrapped by the regenerated aggregate particles through a secondary strengthening method, thereby improving the mechanical property and the durability of an asphalt mixture.

The technical scheme is as follows: in order to achieve the purpose, the invention is realized by the following technical scheme:

a composite strengthening method for regenerated aggregate particles of building waste adopts a composite strengthening mode, and realizes the strengthening of weak parts of the regenerated aggregate particles by respectively utilizing physical abrasion, nano permeable waterproofing agent plugging and high-elasticity waterproof coating wrapping modes. The method comprises the following specific steps:

(1) the regenerated aggregate particles crushed by the construction waste are screened by a square hole screen to reserve the regenerated aggregate particles with the particle size of more than 2.35 mm;

(2) placing the screened and reserved regenerated aggregate particles into a los Angeles abrasion tester, and sieving the abraded regenerated aggregate particles again through a square-hole screen with the particle size of 2.35mm after the operation of a roller without placing a steel ball;

(3) spraying a nano permeable waterproofing agent on the surfaces of the regenerated aggregate particles obtained in the step (2) to wrap the particles, and drying the treated regenerated aggregate particles to obtain a pretreated regenerated aggregate;

(4) spraying high-elasticity waterproof paint on the pretreated regenerated aggregate particles, and drying the treated regenerated aggregate particles to obtain the composite reinforced regenerated aggregate particles.

The composite reinforcing method for the building waste regenerated aggregate particles according to claim 1, wherein a square-hole sieve is adopted in the sieving in the step (1) and the sieving in the step (2).

Further, the composite strengthening method of the building waste regenerated aggregate particles comprises the step (1) of crushing the cement concrete building waste to prepare the regenerated aggregate particles, wherein the regenerated aggregate particles mainly comprise old mineral particles and cement mortar wrapped by the old mineral particles, and the regenerated aggregate particles with the particle size range of 2.35 mm-19 mm are retained by a square hole sieve.

Further, the composite strengthening method of the building waste regenerated aggregate particles comprises the steps of (2) placing the regenerated aggregate particles in a los Angeles abrasion tester according to the mass of 20 kg/part, without placing steel balls, controlling the rotating speed to be 100r/min, re-sieving the regenerated aggregate particles after running for 5 minutes, removing weak cement laitance on the surfaces of the particles through mutual collision friction of particle bodies, keeping the particles with the particle sizes of 2.35 mm-19 mm, and placing the particles outdoors for drying after washing.

Further, in the composite strengthening method for the regenerated aggregate particles of the building waste, the nano permeable waterproofing agent in the step (3) is an organosilicon nano permeable waterproofing agent, and the using amount of the nano permeable waterproofing agent is 5-6% of the mass of the regenerated aggregate particles.

Further, in the composite strengthening method of the recycled aggregate particles of the construction waste, the high-elasticity waterproof coating in the step (4) is an acrylic emulsion high-elasticity waterproof coating.

Further, in the composite reinforcing method for the recycled aggregate particles of the construction waste, the spraying amount of the high-elasticity waterproof coating in the step (4) is 5-6% of the mass of the recycled aggregate particles.

Further, in the composite strengthening method for the building waste regenerated aggregate particles, the drying temperature in the step (4) is 60 ℃.

Spraying an organic silicon nano permeable waterproofing agent on the dried regenerated aggregate particles to carry out pretreatment, blocking the pore structure of the mortar wrapped by the regenerated particles to reduce the water absorption rate, wherein the amount of the organic silicon nano permeable waterproofing agent is 5-6% of the mass of the regenerated aggregate particles, uniformly wrapping, and then placing the treated regenerated aggregate particles under outdoor conditions for drying for 5-7 d; and (4) spraying acrylic emulsion high-elasticity waterproof paint on the pretreated regenerated aggregate particles, further reducing the water absorption of the regenerated particles, simultaneously improving the strength and the asphalt adhesion, wherein the using amount of the acrylic emulsion high-elasticity waterproof paint is 6% of the mass of the regenerated aggregate particles, and drying the treated regenerated aggregate particles at 60 ℃ for 1-2 hours to prepare the composite reinforced regenerated aggregate particles.

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

(1) according to the method, the porous medium with the cement mortar wrapped by the regenerated aggregate particles can be permeated and blocked by spraying the nano permeable waterproof agent, so that the porosity of a weak part is effectively reduced;

(2) according to the method provided by the invention, the high-elasticity waterproof coating is sprayed, the porosity is further reduced on the basis of pre-reinforcement, the effects of flattening rough surfaces of different materials of the regenerated aggregate particles, improving the crushing resistance, wear resistance and adhesion of the materials are realized, and the stress characteristic of the regenerated aggregate particles in the asphalt mixture is effectively improved;

(3) the cost of raw materials related by the invention is low, the mass of the nano permeable waterproof agent and the high-elasticity waterproof coating is only 5-6% of the mass of the regenerated aggregate particles, the preparation process is simple, and the large-scale practical production is facilitated.

Drawings

FIG. 1 is a schematic view of cement mortar wrapped with original recycled aggregate particles;

FIG. 2 is a diagram showing the original recycled aggregate particles wrapped with cement mortar after physical abrasion;

FIG. 3 is the cement mortar coated with the regenerated aggregate particles after the emulsified asphalt of comparative example 1 is treated;

FIG. 4 shows cement mortar coated with regenerated aggregate particles after treatment with sodium water glass of comparative example 2;

FIG. 5 shows the cement mortar coated with the regenerated aggregate particles after the composite strengthening in the example, wherein a is the result of the treatment of the organosilicon-based nano permeable waterproofing agent, and b is the result of the treatment of the acrylic emulsion high-elasticity waterproofing coating.

Detailed Description

The method for reinforcing the recycled aggregate particles of construction waste according to the present invention will be further described with reference to the following embodiments.

The following construction waste regenerated aggregate particle composite strengthening method is adopted in the following embodiments, and comprises the following steps:

(1) selecting a particle product obtained by crushing cement concrete building waste as a regenerated aggregate particle, and primarily screening the regenerated aggregate particle by using a square-hole screen of 2.35mm and 19mm according to the classification standard of the particle size of the coarse aggregate of the asphalt mixture, so as to remove the regenerated aggregate particle with the particle size of less than 2.35mm and more than 19 mm;

(2) 20000 g/part of the regenerated aggregate particles after primary screening are taken and placed in a los Angeles abrasion tester, steel balls are not needed to be placed, the cement laitance with weak surface is eliminated through mutual collision and friction of the regenerated aggregate particles in the rotating process, the rotating speed is controlled to be 100r/min, the regenerated aggregate particles are sieved again by square hole sieves with the sizes of 2.35mm, 4.75mm, 9.5mm, 13.2mm, 16mm and 19mm after running for 5 minutes, the regenerated aggregate particles with different particle sizes are obtained, and the regenerated aggregate particles are placed outdoors for drying after being washed;

(3) weighing 20000g of regenerated aggregate particles with required particle sizes according to the grading requirements of the asphalt mixture, simultaneously measuring 1200g of organosilicon nanometer permeable waterproofing agent by using a spraying pot, uniformly spraying the organosilicon nanometer permeable waterproofing agent on the surfaces of the regenerated aggregate particles, stirring the regenerated aggregate particles in the spraying process so as to be uniformly coated, and drying the pretreated regenerated aggregate particles for 5-7 days under outdoor conditions;

(4) taking 20000g of the pretreated regenerated aggregate particles, measuring about 1000-1200g of the acrylic emulsion high-elasticity waterproof coating by using a spraying pot, uniformly spraying the acrylic emulsion high-elasticity waterproof coating on the surfaces of the regenerated aggregate particles, turning the regenerated aggregate particles in the spraying process so as to be uniformly wrapped, and drying the treated regenerated aggregate particles in a 60 ℃ drying oven for 1-2 hours to prepare the composite reinforced regenerated aggregate particles.

Examples

And (3) carrying out primary screening on regenerated aggregate particles prepared by crushing the cement concrete building waste by adopting a 2.35mm and 19mm square-hole sieve, and reserving the regenerated aggregate particles within the range of 2.35 mm-19 mm.

And taking the regenerated aggregate particles according to the dosage of 20000 g/part, placing the regenerated aggregate particles into a los Angeles abrasion tester at 100r/min, re-sieving the regenerated aggregate particles after running for 5 minutes, dividing the regenerated aggregate particles into particle sizes of 2.35mm, 4.75mm, 9.5mm, 13.2mm, 16mm and 19mm, and drying the regenerated aggregate particles for later use after washing with water.

Weighing the regenerated aggregate particles according to 20000 g/part respectively, firstly weighing 1000g of organosilicon nano permeable waterproofing agent and uniformly spraying the organosilicon nano permeable waterproofing agent on the particle surface, after fully drying, weighing 1200g of acrylic emulsion high-elasticity waterproof coating and uniformly spraying the acrylic emulsion high-elasticity waterproof coating on the particle surface, and drying in an oven at 60 ℃ for 1h to prepare the composite reinforced regenerated aggregate particles.

Comparative example 1:

and (3) carrying out primary screening on regenerated aggregate particles prepared by crushing the cement concrete building waste by adopting a 2.36mm and 19mm square-hole sieve, and reserving the regenerated aggregate particles within the range of 2.36 mm-19 mm.

And taking the regenerated aggregate particles according to the dosage of 20000 g/part, placing the regenerated aggregate particles into a los Angeles abrasion tester, running for 500r, sieving again, dividing the regenerated aggregate particles according to the particle sizes of 2.36mm, 4.75mm, 9.5mm, 13.2mm, 16mm and 19mm, washing with water, and drying for later use.

Weighing the regenerated aggregate particles according to 20000 g/part, and mixing the materials according to the following ratio: and (2) preparing a strengthening solution by using water =1:2, soaking the regenerated aggregate particles for 120min, draining, and drying outdoors for later use.

Comparative example 2:

and (3) carrying out primary screening on regenerated aggregate particles prepared by crushing the cement concrete building waste by adopting a 2.36mm and 19mm square-hole sieve, and reserving the regenerated aggregate particles within the range of 2.36 mm-19 mm.

And taking the regenerated aggregate particles according to the dosage of 20000 g/part, placing the regenerated aggregate particles into a los Angeles abrasion tester, running for 500r, sieving again, dividing the regenerated aggregate particles according to the particle sizes of 2.36mm, 4.75mm, 9.5mm, 13.2mm, 16mm and 19mm, washing with water, and drying for later use.

Weighing the regenerated aggregate particles according to 20000 g/part, and weighing the regenerated aggregate particles according to sodium water glass: water =1:1, the strengthening solution is prepared, and the regenerated aggregate particles are soaked for 12 hours and then dried in an oven at 100 ℃ for standby.

The properties of the reclaimed aggregate particles reinforced by the examples and the comparative examples are shown in Table 1.

TABLE 1 indexes of properties of regenerated aggregate particles by different strengthening modes

Reinforcing method	Crush value/%)	Water absorption/%)	Apparent relative density/g/cm3	Adhesion rating
					Examples	15.87	1.03	2.71	5
Comparative example 1	19.27	2.62	2.57	5
					Comparative example 2	21.40	4.12	2.65	3
Virgin recycled aggregate	24.15	5.05	2.34	4
					Natural aggregate	14.67	0.94	2.75	5

According to the index parameters of the embodiment and the comparative example, the composite strengthening method provided by the invention can effectively improve various performance indexes of the regenerated aggregate particles, the strengthened value is close to that of natural aggregate, and an effective technology is provided for the utilization of solid waste materials.

According to analysis, the embodiment of the invention firstly adopts the organosilicon nanometer permeable waterproofing agent to carry out reinforcement treatment on the regenerated aggregate particles, so that the micro pores of the cement mortar can be effectively infiltrated, and the adhesion performance of the cement mortar phase is improved; secondly, the spraying of the acrylic emulsion high-elasticity waterproof coating can obviously reduce the macro roughness of regenerated aggregate particles, particularly the surfaces of the attached cement mortar, and reduce the damage of an adhesion interface caused by sharp edges and corners. The implementation of the composite mode effectively reduces the water absorption of the regenerated aggregate particles and improves the compressive strength and the adhesion of the regenerated aggregate particles. In the comparative example 1, the commonly used emulsified asphalt is adopted as a reinforcing material, so that the cost is low, but effective wrapping cannot be formed on the surfaces of regenerated aggregate particles after demulsification, and the situations of surface wrapping emulsified asphalt loss and the like caused by high-temperature mixing in the process of preparing asphalt concrete exist; in comparative example 2, common sodium silicate is also used as a reinforcing material of the recycled aggregate particles, the adhesion with asphalt after drying is poor, and various performance indexes are not obviously improved.

In addition, in order to further explain the advantages of the method in the aspect of strengthening the regenerated aggregate particles, the appearance conditions of the cement mortar wrapped by the regenerated aggregate particles treated by different strengthening modes are respectively observed by using a scanning electron microscope.

Fig. 1 shows that the original recycled aggregate particles are wrapped with cement mortar, and it can be seen that the original attached cement mortar has more pores and a rougher surface, which adversely affects the adhesion.

Fig. 2 shows that the original recycled aggregate particles are wrapped with cement mortar after physical abrasion, and it can be seen that the surface roughness of the attached cement mortar after physical abrasion is effectively reduced, but more micropores still exist.

FIG. 3 shows a comparative example 1, in which the recycled aggregate particles are wrapped in cement mortar after the emulsified asphalt is treated, and it can be seen that the emulsified asphalt can be better wrapped on the surface of the cement mortar, but is easy to run off during high-temperature mixing.

FIG. 4 shows comparative example 2, in which the regenerated aggregate particles are coated with cement mortar after sodium silicate treatment, it can be seen that there are many cracks in the thin film formed by the sodium silicate material, which results in failure to effectively reduce the water absorption.

FIG. 5 shows the cement mortar wrapped by the regenerated aggregate particles after the composite strengthening in the embodiment, and it can be seen that a is a graph in which the regenerated aggregate particles are uniformly wrapped on the surface of the cement mortar after being treated by the organosilicon nano-permeable waterproofing agent and effectively penetrate into micropores to block the micropores; and the figure b shows that after the acrylic emulsion high-elasticity waterproof coating is treated, the surface roughness is effectively reduced, and the stress concentration caused by edges and corners is reduced.

The conforming method provided by the invention can effectively realize pore plugging and strengthening through the secondary strengthening technology, and has advantages compared with other technologies.

The foregoing illustrates only specific embodiments of the invention. It is apparent that the present invention is not limited to the above embodiments, and any modifications and changes made to the present invention within the scope of the claims of the present invention should be construed as the scope of the present invention.