Study On The Infulence Factors Of Frost Resistance Of Pervious Concrete With PAN Fiber And Silica Fume

Pervious concrete is an excellent road material in the construction of sponge city in our country.It has the advantages of improving urban ecosystem,improving travel safety and increasing the collection and utilization of urban rainwater because of its excellent permeability.As a result,it has more engineering applications in our country.The large number of connected pores decide that the disadvantage of strength and durability is obvious.And the geographical and climatic conditions of our country are very different,which greatly limits the application of pervious concrete in the whole country.Most of the engineering application cases of pervious concrete are concentrated in the southern region.The reason why limits its spread in northern region is frost resistance.Therefore,there is of great importance to study the frost resistance in order to applicate in north.The idea of studying frost resistance by molding method and material composition is put forward based on the factors affecting the basic properties of pervious concrete.Select the molding parameters,the ratio of water and cement and admixture content as factors to design the orthogonal test,and reference to existing specifications for pervious cement concrete and ordinary concrete to test permeability coefficient,porosity and compressive strength.Combined with the characteristics of rain-snow weather in the north,the mass loss rate and relative dynamic elastic modulus with rapid freezeing was selected as indexes to ecaluate frost resistance.The influence of various factors on the performance of pervious concrete is systematically studied.The main research contents of article are as follows:Firstly,under the condition that the mix is constant,the pervious concrete is made by the method of adding fiber and silica fume,and the basic properties and frost resistance of pervious concrete were measured by orthogonal design of different molding methods,The results of basic performance and frost resistance are analyzed by means of range and variance analysis.Finally,the final anti-freezing molding scheme is obtained by comprehensive analysis,and the relationship between the basic performance and the frost resistance is established.Secondly,based on the results of molding group,study its basic properties and frost resistance by changing the composition of materials under the condition of constant molding mode.In the same way,the basic properties and frost resistance indexes of different stages are analyzed by orthogonal test,and the optimum content of each component material under freeze-thaw condition is obtained.Finally,the design scheme of frost resistance of pervious concrete from material selection to preparation is put forward.