Experimental Study On Mix Proportion Optimization Of High Temperature Heat Storage Concrete

Conventional fossil energy consumption has caused a series of problems such as energy shortage,environmental pollution.The development of efficient solar-thermal power generation system is one of the important ways to solve the energy problem.Heat storage system is an important subsystem of solar-thermal power generation system.Therefore,how to improve its performance has become the hot spot of reseach.Based on theoretical analysis and experimental research,combining the mechanical and thermal properties,this paper optimized the concrete mix proportion for high temperature heat storage.This paper compared the mechanical performance of concrete thermal storage material for 13 kinds of mix proportion and 5 kinds of heat treatment,then concrete thermal physical properties tests were performed for the 3 kinds of better proportion with the optimal heat treatment.It can be concluded as follows:The heating pretreatment with Less than 3 ?/min can satisfy the mechanical strength of concrete material;The concrete material with iron ore as fine aggregate has low mechanical strength and poor heat resistant performance.the strength of concrete with 3% graphite and 2% steel fiber is 29.40 MPa,and it can meet the requirements of basic industrial strength;added 2% iron powder into the concrete as fine aggregate,it can improve the strength of concrete more effectively.The concrete with iron ore reached the maximum of heat capacity at 400 ?,and the value is 5.5 J/(g K).Compared to normal concrete,specific heat of the adding graphite powder and steel fiber concrete is higher and its best use temperature range is 300~500 ?.Iron sand as fine aggregate can effectively improve the overall thermal conductivity,and its thermal conductivity increased by 118.6%.Compared with ordinary concrete,coefficient of thermal conductivity of the concrete with 2% added steel fiber,3% added graphite powder increased by 105.2%.At the same time,it can guarantee the mechanical strength which is still higher than industrial basic requirements after high temperature.