Research On The Technology And Properties Of New-type Of Permeable Concrete

Urbanization and large-area hardening pavement change the natural balance of water,causing many problems such as urban droughts and floods,thermal effects,and reducing people's quality of life.How to deal with these problems has become the focus of social attention.Permeable paving is one of the solutions.It can be divided into pervious bricks and pervious concrete from the production method.The traditional pervious concrete mainly uses single-graded or discontinuously-graded coarse aggregates,with little or no fineness.Aggregates are made by bonding with cementitious materials and using special techniques.After the paving,it has the functions of infiltration of rainwater and sound absorption of ventilation,which can achieve the purpose of covering precipitation,reducing surface runoff and absorbing heat and reducing noise.The purpose of this article is to prepare a pervious concrete with a new hole making process.The main tasks are as follows:1.Based on the basic characteristics of traditional pervious concrete,putting forward the idea of making pervious concrete with pores of degradable materials which proposed to simplify the preparation process of pervious concrete,which does not require much special requirements and is easy to operate.2.According to the composition and production process of concrete,the basic requirements for the preparation of permeable concrete degradable materials are proposed,including sufficient abrasion resistance,mechanical strength such as tensile and shear resistance,resistance to concrete and alkaline environment,and density compatibility is well.easy to shape,not easy to absorb water,environmental protection,within a certain period of time after concrete molding which can be degraded in a more densely closed environment of concrete and degradables harmless,suitable for cost.3.Under the circumstance of satisfying basic requirements,research on natural degradable macromolecules and capsule-like structures was conducted.For the first time,trials of some natural macromolecule materials and capsule-like structures for the preparation of permeable concrete were carried out.The reasons for success or failure were analyzed and summarized,and research ideas' adjustments were made..4.Proposing PAG-degradable material as a pore-forming agent.According to the test conditions,it was modified with N-N' methylene bisacrylamide,and the modified PAG with excellent performance and satisfying conditions was obtained,and prepare a new type of permeable concrete.5.The pervious performance test was carried out on the permeable concrete specimens.The porosity of the specimens was between 29.29% and 41.65%,and the water permeability coefficient was between 2mm/s and 13mm/s.The water permeability was good.,and it can be adjusted by changing the PAG degradable material content and other factors.6.The laboratory mechanical properties of the new type of permeable concrete were tested.The 7d compressive strength of the specimen was about 10 MPa,the 28 d compressive strength was about 20 MPa,and the splitting tensile strength was between 0.86 and 2.01 MPa.All three can reach the strength level of existing permeable concrete,and also have a great room for improvement.7.The factors such as water-cement ratio,aggregate particle size,PAG degradable material length,and degradable material content were studied by orthogonal experi--mental design method.It was concluded that the significant contributing factor to the permeability and mechanical properties was the amount of degradable material.This paper proposes a new idea for the preparation of pervious concrete,and carries out some experiments.The conclusions obtained have certain reference significance for the application and research of engineering.