Experimental Study On Pervious Concrete With Different Admixtures

Permeable concrete is a new kind of environment-friendly material,which is widely used in light traffic roads,parks and squares.In order to have good permeability,Permeable concrete is usually prepared by adding a small amount or no fine aggregate,which makes its structure porous.Therefore,Permeable concrete is often not high strength and durability.In order to improve the mechanical properties of Permeable concrete while maintaining its permeability,this paper intends to mix silica fume,fly ash,basalt fiber into Permeable concrete to improve the performance of Permeable concrete.This paper studies the influence factors of aggregate and aggregate gradation,water-binder ratio,design porosity,etc.of Permeable concrete,and obtains the optimal mix ratio of Permeable concrete.Based on ordinary permeable mix ratio,appropriate amount of silica fume,fly ash and basalt fiber added to study the influence of addition of silica fume,fly ash and basalt fiber on the performance of Permeable concrete.The research results are as follows:(1)Water-binder ratio and designed porosity are the main factors affecting the performance of Permeable concrete.For diabase aggregate with a particle size of 5-10 mm,the optimal water-binder ratio is 0.25,the designed porosity is 18%,the compressive strength is 34.00 MPa,and the permeability coefficient is 1.73 mm /s.(2)The influence of mineral admixtures on the performance of Permeable concrete.For a single graded diabase aggregate with a particle size of 5-10 mm,the water-binder ratio is 0.25,and the designed porosity is 18%.For ordinary Permeable concrete with silica fume and fly ash,the optimal content is 6% and 10%,the strength of Permeable concrete is 35.65 MPa and 29.65 MPa,and the permeability coefficient is 5.44mm/s and 4.60mm/s.When fly ash and silica fume mixed together,the optimal content is 6% silica fume and 15%fly ash mixed,the strength of Permeable concrete is 38.17 MPa,and the permeability coefficient is 2.09mm/s.(3)Basalt fiber Permeable concrete is a single graded diabase aggregate with a particle size of 5-10 mm,a water-binder ratio of 0.25,and a designed porosity of 18%.Basalt fiber is added to the base,and its optimal content is about 0.10%.The strength of Permeable concrete is 35.01 MPa,and the permeability coefficient is 3.77mm/s.At the same time,the optimal content of Permeable concrete mixed with basalt fiber and silica fume is 0.10% and 6%,respectively.At this time,the strength of Permeable concrete is 48.29 MPa,and the permeability coefficient is 2.89mm/s.At the same time,the optimal mix of Permeable concrete mixed with basalt fiber,silica fume and fly ash is 0.10%,6% and 10%,respectively.At this time,the strength of Permeable concrete is 42.66 MPa,and the permeability coefficient is 2.40mm/s.(4)There is a good correlation between the strength and permeability coefficient of Permeable concrete,and the variation law of Permeable concrete with the cementitious material can be estimated by the use of multiple linear fitting of the amount of cementitious material,which can be used as a reference for future engineering applications.