Optimal Design of High Proportion Mixed Material Concrete Based on Laboratory Test
In order to reduce the application cost of concrete,the optimization design of concrete mix proportion with high proportion ad-mixture was carried out.The flow properties,mechanical properties and hydration properties of concrete were studied by single factor test of mineral powder,single factor test of gypsum,mechanical sand replacement test and concrete test instrument.The results show that:(1)Adding mineral powder can improve the flow and mechanical properties of concrete compared with the non-adding mineral powder;Corresponding to each age,with the increase of mineral powder content,the hydration heat of concrete gradually decreases.The optimum dosage is 30 kg/m3,which has beneficial effects on the expansion,compressive strength,splitting tensile strength and hydra-tion properties of concrete.(2)Compared with without gypsum,with the increase of gypsum content,the concrete expansion first increa-ses and then decreases,and the 7 d,28 d compressive strength and splitting tensile strength of concrete first increase and then de-crease;Through the favorable influence of gypsum on the flow and mechanical properties of concrete,the optimal dosage is 20 kg/m3.(3)Compared with unmixed machine-made sand,the 7 d and 28 d compressive strength and splitting tensile strength of concrete first increased and then decreased with the increase of machine-made sand substitution rate,and the mixed properties gradually deteriora-ted.According to the favorable influence of machine-made sand on the flow and mechanical properties of concrete,the optimal re-placement rate is 60%,that is,504 kg/m3.(4)Replace cement with mineral powder and gypsum to reduce the cement content by 50 kg/m3;By replacing river sand with machine-made sand,the river sand content is reduced by 40%,and the application of high proportion of blended materials is realized.
laboratory testhigh proportion of blended materialsflow performancemechanical property
NETL
NSTL
万方数据
