Study On The Preparation And Performance Of Planting Porous Concrete Based On Recycled Coarse Aggregate

Recycled aggregate planting porous concrete consisted of recycled aggregate skeleton structure,cement,fly ash as cementitious materials,prepared with a specific mixing technology and molding process and contains a large number of connected voids,is a no-fines concrete,ecological concrete.Recycled-aggregate planting porous concrete can be widely used in slope protection,road pavement,noise control,water purification,aquatic habitat in all aspects,with high compressive strength,waste utilization,connected porosity,permeability,air permeability and suitable pH value of plant growth.Based on the target porosity as control parameter and volume method for mix design to prepare recycled aggregate planting porous concrete of continuous gradation,single gradation with target porosity were graded 0.25,0.28,0.31,and water cement ratio 0.30 of single gradation mixed fly ash.Research on the mixing process,molding process,curing process.It was found that when the target porosity unchanged,with the increase of water cement ratio(0.20-0.40),the compressive strength of recycled aggregate green porous concrete increases at first and then decreases,when water cement ratio is 0.30,the compressive strength reached the peak,the permeability coefficient slightly increased with the increase of water cement ratio;when the water cement ratio unchanged,with the increase of target void ratio(25%-31%),compressive strength gradually decreased,when the void ratio increased by 3%,compressive strength was reduced by approximately 6-8MPa,the permeability coefficient also increased significantly with increase of the water cement ratio;when the water cement ratio and target void ratio unchanged,with the increase of fly ash(0-40%),the compressive strength increases first and then decreases,when the volume is 20% reached peak.Using the method of acid-base neutralization to reduce pH value,choosing the tall fescue as herbal studies,preparing planting material to plant tall fescue.The study found that the germination of the tall fescue is 7d,14 d roots reach more than 7 cm,28 d plant long to more than 30 cm and roots can penetrate 7cm planting porous concrete.