Preparation And Properties Of Steel Pervious Concrete Modified By SAP

As a new type of ecological concrete,pervious concrete can not only effectively solve the problem of urban flooding,but also relieve the pressure of urban drainage system and improve the urban “heat island effect”.So,pervious concrete is the important material basis for the construction of "sponge city",and has been used in urban roads construction more and more widely.Combined with the recycling of industrial solid waste in green building materials,steel slag as aggregate in pervious concrete not only makes rational use of resources and turns waste into treasure,but also solves the problem of piling of steel slag with a large scale land occupying and polluting the environment.The road performance of steel slag pervious concrete is lower than that of ordinary concrete,and pervious concrete itself can not effectively store and make full use of natural precipitation.Considering adding of SAP(Super Absorbent Resin),the steel slag pervious concrete was modified and prepared.The water retention,water release capacity,pavement performance effect and influencing factors of SAP on steel slag pervious concrete were discussed.The main research contents are as follows:(1)The physical properties,chemical composition and stability of steel slag were analyzed,and the feasibility and basic properties of pervious concrete prepared with steel slag as aggregate were explored.(2)Preparing steel slag pervious concrete,experimental research on the influence of water cement ratio,slurry collection ratio,aggregate size,age and forming method on the working performance of steel slag pervious concrete were carried out.(3)The steel slag pervious concrete was modified by adding different amount of SAP,whose adding amount were 0 %,0.2 %,0.5 % and 1 % of cementitious material respectively.The compressive strength and permeability coefficients of steel slag pervious concrete for 7 d and 28 d were measured,and the optimum mixing ratio for comprehensive performance is 0.5 %.(4)The addition of SAP can improve the moisture distribution in concrete,and make the hydration reaction of cement fuller,and increase the internal porosity of concrete,which has a positive impact on the strength and permeability of concrete.(5)The use of SAP significantly improves the water retention and water release properties of pervious concrete.SAP can absorb part of water during precipitation and store it in the body.When the temperature of external environment increases,the water absorbed by SAP can release slowly that is very suitable for the construction of "sponge city".In addition,the evaporation and heat dissipation of SAP steel slag pervious concrete at high temperature can reduce the temperature of pervious concrete pavement and environment to a certain extent.