WO2021129020A1

WO2021129020A1 - Preparation and construction method of porous coral aggregate permeable purified concrete

Info

Publication number: WO2021129020A1
Application number: PCT/CN2020/118602
Authority: WO
Inventors: 尹世平; 梁向州; 戴君岩; 苏讯; 董朋杰
Original assignee: 尹世平
Priority date: 2019-12-27
Filing date: 2020-09-29
Publication date: 2021-07-01
Also published as: CN110981366A

Abstract

Provided is a preparation and construction method of porous coral aggregate permeable concrete, which belongs to the technical field of building materials and applications. The coral aggregate is crushed, and the crushed and sieved coral coarse aggregate, coral sand, and coral micro-sand are cleaned with tap water and dried, the coral sand, coral micro-sand, wood chips, cement, mineral powder, fine dust beads, and water are mixed in a horizontal mixer according to the mass ratio to prepare a high-permeable coral mortar, then, the high-permeable coral mortar is mixed with the coral coarse aggregate according to the mass ratio, and cured for 28 days under the conditions of 20°C and humidity greater than 95% to obtain the porous coral aggregate permeable concrete. Coral sand is used instead of ordinary river sand, and some coral micro-sand is used to replace cement, which increases the permeability of coral mortar. During the mixing process of cement mortar, coral micro-sand absorbs water, which reduces the local water-cement ratio of the contact surface with cement, which improves the bonding performance of the interface, and increases the overall strength of the permeable concrete.

Description

Preparation and construction method of porous coral aggregate water-permeable purified concrete

Technical field:

The invention relates to the technical field of building material application, in particular to a preparation and construction method of porous coral aggregate water-permeable and purified concrete.

Background technique:

Permeable concrete is a kind of porous lightweight concrete composed of aggregate, cement slurry and water, and contains a large number of connected pores. In permeable concrete, the proportion of water and cementitious material is strictly controlled to form a flowing slurry, a suitable coating is formed around the coarse aggregate particles, and a highly permeable, interconnected pore system is formed to achieve rapid drainage. Research shows that permeable concrete pavement is a unique and effective method to meet the increasing environmental demands. Compared with ordinary concrete pavement, the use of permeable concrete pavement can absorb rainwater and make it penetrate to the ground, help protect and replenish groundwater, reduce rainwater runoff, prevent groundwater and skidding, replenish groundwater and underground aquifers, and support the Continue to build. However, because the permeability of aggregate determines the water permeability of permeable concrete, most of the existing permeable concrete aggregates are made of ordinary stones, and the particle size of the stones is mostly single-grain or intermittent. Due to the poor water permeability of the stone itself, the main water permeability function is Relying on the interstices of stone aggregates for water permeation. The porosity of ordinary permeable concrete aggregates is between 15% and 25%, and the water permeability is around 3.0mm/s, which cannot meet the timely drainage requirements of urban waterlogging caused by continuous rainfall in the city. It is an urgent need. A big problem solved. The existing ordinary permeable concrete aggregates are ordinary stones, and the particle size of the stones is mostly single-grain or intermittent. The stones themselves have poor water permeability, and their bonding performance with cementing materials is not as good as coral aggregate. The permeable function of ordinary concrete mainly relies on the gap between the stone aggregates for water permeation, while the coral aggregate permeable concrete can use the aggregate gap for water permeation and the coral aggregate itself for water permeation.

Summary of the invention:

Technical problem: The purpose of the present invention is to overcome the deficiencies in the prior art and provide a method for preparing and constructing porous coral aggregate water-permeable and purified concrete, so as to solve the problem that the water-permeability of traditional permeable concrete cannot meet the needs of rapid drainage of large numbers of urban waterlogging problem.

Technical Solution: The method for preparing porous coral aggregate water-permeable concrete of the present invention includes the following steps:

a. Crush the coral aggregates in a crusher, sieving to obtain coral coarse aggregates, coral sand and coral micro-sands, clean the coral coarse aggregates, coral sands and coral micro-sands with tap water to remove mud and dry them;

b. Mix the coral sand, coral micro-sand, wood chips, cement, mineral powder, fine dust beads, and water in a horizontal mixer according to the mass ratio to obtain a highly permeable coral mortar;

c. Mix coral coarse aggregate and high-permeability coral mortar at a mass ratio of 2.5:1 to prepare porous coral aggregate permeable concrete, and cure for 28 days under the conditions of 20°C and humidity greater than 95%.

The drying temperature of the coral coarse aggregate, coral sand and coral fine sand is drying at 105° C. for 24 hours.

The said coral coarse aggregate has a particle size of 5-20 mm, a barrel compressive strength of not less than 2.5 MPa, a porosity of not less than 40%, and an hourly water absorption rate of not less than 10%.

The wood chips are prepared under wet conditions and have a density of 0.6 g/cm ³ .

The particle size of the coral micro-sand is 0-0.3mm, and the water absorption rate is not less than 10%.

The cement is P.O 52.5R cement, the grade of mineral powder is S105, the particle size is 325 mesh, and the grade of fine dust bead is grade 1 and the particle size is 525 mesh.

The coral sand has a particle size of 0.3-4.75 mm.

A construction method of porous coral aggregate water-permeable concrete: firstly lay the lower geotextile on the base layer, then lay the gravel layer and the upper geotextile, and finally lay the porous coral aggregate according to claim 1 on the upper geotextile Coral aggregate permeable concrete layer obtained by the preparation method of permeable concrete.

Beneficial effects: The present invention is based on the porous characteristics of coral coarse aggregate, coral sand, and coral micro-sand, so the permeability of coral sand and coral micro-sand is much higher than that of ordinary river sand. Coral sand is used instead of ordinary river sand, and some coral micro-sand is used instead of cement to increase the permeability of coral mortar, which has a low impact on strength. Coral micro-sand also has a water-absorbing and internal curing effect. During the mixing process of cement mortar, coral The micro-sand absorbs water, so that the local water-cement ratio of the contact surface with the cement is reduced, thereby improving the bonding performance of the interface and increasing the overall strength of the water-permeable concrete. Due to the high adsorption of wood chips, it exhibits high water retention and gas filtering capabilities. The use of wood chips has high absorption of heavy metal ions and can improve the slip resistance of cement mortar to meet the requirements of road use. The use of coral aggregate permeable concrete can not only use the gap between the aggregates for water penetration, but also use the coral aggregate itself for water penetration. The main advantages compared with the existing technology:

(1) Coral aggregate concrete has high water permeability, the porosity of coral aggregate is between 45-65%, and the water permeability is greater than 5.0mm/s, which can meet the needs of rapid drainage.

(2) Coral bones are used as aggregates. Coral bones are usually cleaned out in the process of dredging the channel. They are produced in the southeastern coastal cities and islands in the South China Sea, which is beneficial to the reuse of waste resources.

(3) Improve water retention and gas filtration capacity, and play a positive role in soil and water conservation.

(4) It has the function of purifying sewage and adsorbing heavy metal ions in the water.

(5) Due to the high porosity of aggregate and mortar, it has sound insulation and sound absorption effects.

(6) The addition of sawdust improves the slip resistance and prevents pedestrians from falling.

(7) The reasonable ratio of mineral admixture improves the wear resistance and meets the needs of road wear resistance.

(8) Ordinary aggregate permeable concrete adopts cement mortar and sand-gravel method: 1) Now put all the coarse aggregate and water into the mixer and mix; 2) Put in the cementitious material and sand for full mixing; 3) Discharge the concrete . The feeding method used in the present invention: 1) Put the coral sand, coral fine sand, wood chips, cement, mineral powder, fine dust beads, and water into a mixer for mixing; 2) put coral aggregates; 3) concrete out material. The feeding method in the present invention can fully mix the cementitious material, coral sand and wood chips, and avoids putting coarse aggregate first. As the aggregate absorbs water, the cementitious material adheres to the aggregate to form a dry and hard block, which prevents mixing. If sufficient, coral sand and sawdust will be unevenly dispersed.

Description of the drawings

Fig. 1 is a schematic diagram of the coral aggregate permeable concrete layer constructed by the porous coral aggregate permeable concrete of the present invention.

Detailed ways:

The method for preparing porous coral aggregate water-permeable concrete of the present invention includes the following steps:

a. Crush the coral aggregates in a crusher, sieving to obtain coral coarse aggregates, coral sand and coral micro-sands, clean the coral coarse aggregates, coral sands and coral micro-sands with tap water to remove mud and dry them; The particle size of the coral coarse aggregate is 5-20mm, the barrel compressive strength is not less than 2.5MPa, the porosity is not less than 40%, the particle size of the coral fine sand is 0-0.3mm, and the water absorption rate is not low. The coral sand has a particle size of 0.3-4.75 mm; the drying temperature of the coral coarse aggregate, coral sand and coral fine sand is dried at 105° C. for 24 hours.

b. Mix the coral sand, coral micro-sand, wood chips, cement, mineral powder, fine dust beads, and water in a horizontal mixer according to the mass ratio to obtain a highly permeable coral mortar; the water absorption rate is not less than 10% in one hour; The sawdust is prepared under wet conditions, and its density is 0.6g/cm ³ ; the cement is PO 52.5R cement, the grade of mineral powder is S105, the particle size is 325 mesh, the grade of fine dust bead is level 1, and the particle size is S105. 525 mesh diameter.

c. Mix coral coarse aggregate and high-permeability coral mortar at a mass ratio of 2.5:1 to prepare porous coral aggregate permeable concrete, and cure for 3-28 days under the conditions of 20-75°C and humidity greater than 95% .

The construction method of porous coral aggregate water-permeable concrete of the present invention: firstly lay the lower geotextile on the base layer, then lay the gravel layer and the upper geotextile, and finally lay the porous coral as claimed in claim 1 on the upper geotextile Coral aggregate permeable concrete layer obtained by the preparation method of coral aggregate permeable concrete.

Example 1

Step 1: The preparation method of porous coral aggregate ecological concrete. The coral aggregate is crushed by a jaw crusher, and the coral coarse aggregate and coral sand are sieved to obtain coral aggregate with a particle size of 6mm and a particle size of 4mm. Coral sand, coral micro-sand with a particle size of 0.2mm, clean the coral aggregate, coral sand, and coral micro-sand to remove mud, and dry them at 105°C for 24 hours.

Step 2: Mix the coral sand, coral micro-sand, wood chips, cement, mineral powder, fine dust beads, and water in a horizontal mixer at a ratio of 3:3:4:4:1:1:1.8 to obtain high permeability Sexual coral mortar.

Step 3: Mix coral coarse aggregate and high-permeable coral mortar at a mass ratio of 2.5:1 to prepare porous coral aggregate permeable concrete, and cure for 28 days at 20°C and humidity greater than 95%.

Example 2

Step 1: A method for preparing porous coral aggregate ecological concrete. The coral aggregate is crushed by a jaw crusher, and the coral coarse aggregate and coral sand are sieved to obtain a coral aggregate with a particle size of 10 mm. Clean the coral aggregate, coral sand, and coral micro-sand to remove mud from 3mm coral sand and 0.1mm coral micro-sand, and dry them at 105°C for 24 hours.

Step 2: Mix the coral sand, coral micro-sand, wood chips, cement, mineral powder, fine dust beads, and water in a horizontal mixer at a ratio of 3:4:4:3:1:1:1.8 to obtain high permeability Sexual coral mortar.

Step 3: Mix coral coarse aggregate and high-permeability coral mortar according to 2.5:1 to prepare porous coral aggregate permeable concrete, and cure for 28 days under conditions of 20°C and humidity greater than 95%.

Example 3

Step 1: A method for preparing porous coral aggregate ecological concrete. The coral aggregate is crushed by a jaw crusher, and the coral coarse aggregate and coral sand are sieved to obtain a coral aggregate with a particle size of 15mm. 2mm coral sand, 0.05mm coral microsand, clean the coral aggregate, coral sand, and coral microsand to remove mud, and dry them at 105°C for 24 hours.

Step 2: Mix the coral sand, coral micro-sand, wood chips, cement, mineral powder, fine dust beads, and water in a horizontal mixer at a ratio of 3:3:3:4:1:1:1.8 to obtain high water permeability Sexual coral mortar.

Example 4

Step 1: A method for preparing porous coral aggregate ecological concrete. The coral aggregate is crushed by a jaw crusher, and the coral coarse aggregate and coral sand are sieved to obtain a coral aggregate with a particle size of 18mm. Clean the coral aggregate, coral sand, and coral microsand to remove mud from 1mm coral sand and 0.1mm coral microsand, and dry them at 105°C for 24 hours.

Step 2: Mix the coral sand, coral micro sand, wood chips, cement, mineral powder, fine dust beads, and water in a horizontal mixer at a ratio of 2.5:2.5:4:3:1.5:1.5:1.8 to obtain high water permeability Sexual coral mortar.

Step 3: Mix coral coarse aggregate and high-permeability coral mortar according to 2.5:1 to prepare porous coral aggregate permeable concrete, and cure for 14 days under the conditions of 40°C and humidity greater than 95%.

Example 5

Step 1: A method for preparing porous coral aggregate ecological concrete. The coral aggregate is crushed by a jaw crusher, and the coral coarse aggregate and coral sand are sieved to obtain a coral aggregate with a particle size of 8mm. Clean the coral aggregate, coral sand, and coral micro-sand to remove mud from 3mm coral sand and 0.2mm coral micro-sand, and dry them at 105°C for 24 hours.

Step 2: Mix the coral sand, coral micro-sand, wood chips, cement, mineral powder, fine dust beads, and water in a horizontal mixer at a ratio of 2:2:6:4:1:1:1.8 to obtain high permeability Sexual coral mortar.

Step 3: Mix coral coarse aggregate and high-permeability coral mortar according to 2.5:1 to prepare porous coral aggregate permeable concrete, and cure for 7 days under the conditions of 50°C and humidity greater than 95%.

Example 6

Step 1: A method for preparing porous coral aggregate ecological concrete. The coral aggregate is crushed by a jaw crusher, and the coral coarse aggregate and coral sand are sieved to obtain a coral aggregate with a particle size of 10 mm. 2mm coral sand and coral micro sand with a particle size of 0.15 mm, clean the coral aggregate, coral sand, and coral micro sand to remove mud, and dry them at 105°C for 24 hours.

Step 2: Mix the coral sand, coral fine sand, wood chips, cement, mineral powder, fine dust beads, and water in a horizontal mixer at a ratio of 4:2:4:4:1:1:1.8 to obtain high permeability Sexual coral mortar.

Step 3: Mix coral coarse aggregate and high-permeability coral mortar according to 2:1 to prepare porous coral aggregate permeable concrete, and cure for 3 days at 75°C and humidity greater than 95%.

Table 1 Coral Aggregate Permeable Concrete Technical Index Table

Note: Adsorption and gas permeability are the results of 24 hours measurement

Claims

A method for preparing porous coral aggregate water-permeable concrete, which is characterized in that it comprises the following steps:

a. Crush the coral aggregates in a crusher, sieving to obtain coral coarse aggregates, coral sand and coral micro-sands, clean the coral coarse aggregates, coral sands and coral micro-sands with tap water to remove mud and dry them;

b. Mix the coral sand, coral micro-sand, wood chips, cement, mineral powder, fine dust beads, and water in a horizontal mixer according to the mass ratio to obtain a highly permeable coral mortar;

c. Mix coral coarse aggregate and high-permeability coral mortar at a mass ratio of 2.5:1 to prepare porous coral aggregate permeable concrete, and cure for 28 days under the conditions of 20°C and humidity greater than 95%.
The method for preparing porous coral aggregate permeable concrete according to claim 1, wherein the drying temperature of the coral coarse aggregate, coral sand and coral fine sand is drying at 105°C 24 hours.
The method for preparing porous coral aggregate water-permeable concrete according to claim 1, wherein the diameter of the coral coarse aggregate is 5-20mm, the barrel compressive strength is not less than 2.5MPa, and the porosity is not less than 2.5MPa. If it is less than 40%, the one-hour water absorption rate is not less than 10%.
The method for preparing porous coral aggregate water-permeable concrete according to claim 1, wherein the wood chips are prepared under wet conditions and have a density of 0.6 g/cm 3 .
The method for preparing porous coral aggregate water-permeable concrete according to claim 1, wherein the particle size of the coral fine sand is 0-0.3 mm, and the water absorption rate is not less than 10%.
The method for preparing porous coral aggregate water-permeable concrete according to claim 1, characterized in that: the cement is PO 52.5R cement, the grade of mineral powder is S105, the particle size is 325 mesh, and the grade of fine dust beads is 1 Grade, particle size 525 mesh.
The method for preparing porous coral aggregate water-permeable concrete according to claim 1, wherein the coral sand has a particle size of 0.3-4.75 mm.
A construction method of porous coral aggregate water-permeable concrete, which is characterized in that: firstly lay the lower geotextile on the base layer, then lay the gravel layer and the upper geotextile, and finally lay the geotextile described in claim 1 on the upper geotextile Coral aggregate permeable concrete layer obtained by the preparation method of porous coral aggregate permeable concrete.