Research Of Precast High Strength Pervious Concrete Pavement

Pervious concrete pavement is characterized by high safety and driving comfortability,and provides a possible solution to heat island effect,ecological diversity degradation and water resource depletion problems.However,the technical bottlenecks of traditional pervious concrete pavement,such as low strength,high likelihood for loosing and clogging,inconvenient maintenance,hinder its wider application.In this paper,in order to overcome the drawbacks mentioned above,reactive powder concrete and precast concrete pavement technologies were combined to prepare precast high strength pervious concrete pavement based on pores characteristics optimization and permeability efficiency improvement.The main research contents include:(1)Based reactive powder concrete preparation principle,single-factor and orthogonal-factor experiments were conducted.The optimum mix was determined by comparison of flexural strength,compressive strength and workability results.Properties tests and analysis were made on the optimum mix,which include workability,setting time,mechanical properties(flexural and compressive strength,elasticity modulus),shrinkage,durability(freezing and thawing resistance,anti-sulfate)and microscope properties(Scanning Electron Microscope,Differential Scanning Calorimeter,X-ray Diffraction).The results showed the corresponding mix had desirable performance.(2)The key points of manufacturing high strength pervious concrete pavement were studied.Consequently,the forms were designed and pore-forming methods were determined.Properties,which include mechanics and durability(compressive strength,freezing and thawing resistance,anti-sulfate),pore properties and permeability(permeability coefficient,anti-clogging),ecology properties(pH value,thermal conduction),were tested and analyzed.Benefited from the optimized pore structure,the permeability coefficient and compressive strength of the prepared HSPC,with the porosity of 1.26%,achieved 13.02mm/s and 61.37MPa,respectively.And the pH values and thermal conduction test results of HSPC also showed favorable ecology performance,e.g.,suitable for planting.(3)A precast concrete pavement system(PCPS)was developed from the manufactured high strength pervious concrete,in which size and shape of slab,road structure,connecting and load transferring,construction and maintenance process were investigated.The results showed that the PCPS,which was characterized by notch/convex groove connecting and the cleaning dust route of bottom to top,provided an acceptable solution to high likelihood clogging of pervious concrete pavement.