Experimental Investigation On The Effects Of The Elastic Modulus Of SCC

Self-compacting concrete(SCC) has three characteristics as high fluidity, high clearance penetrating and high resistance of segregation since it appears. In recent years, the development of SCC attracted worldwide attention and valued gradually,and the application have been increasing in proportion of concrete products in Japan, Europe,America and other developed countries. At present, the dosage of self-compacting concrete is less than 1% of total dosage of concrete in our countryand it would be have very well development.However,the elastic modulus of SCC is lower than the same level strength of common concrete’s,thus, this paper do the research through mineral admixtures, coarse aggregate and mortar matrix three aspects to analysis how them influence the elastic modulus of SCC,we also used the theory method to estimate the elastic modulus of SCC and Compared with the experimental data.This paper prepared self-compacting concrete with mineral admixtures as fly ash, silica fume, cobble,granite and limestone continuous grading in 5~20mm as c- oarse aggregate and water/cement ratio varied between 0.25 and 0.35,and we stud- ied the influence of the elastic modulus of SCC through the variance of three aspe- cts as the dosage of mineral admixture, species of coarse aggregate and water/ce- ment ratio.The test shows the SCC mixing with fly ash could improve the fluidity,which the early age elastic modulus is low and the later elastic modulus have large deve- lopment,however, the SCC mixing with silica fume could improve the resistance of segregation,which also accelerates the early age elastic modulus of SCC. Study proves composite incorporating 4% fly ash and 20% silica fume could improve the comb-ination property of SCC.Compared with cobble,using grave is conducive to improve the elastic modulus of SCC on the same mix proportion,and because the composition of limestone can occur second hydration reaction with cement hydration products,which the elastic modulus of SCC mixing with is highest.The elastic modulus of mortar matrix is close to the coarse aggregate’s when water/cement ratio is 0.25 and the elastic modulus of SCC is high because of the component has well coordination under loading. Moreover,it is with a certain degree of reliability using theory formula predict the elastic modulus of SCC, and based on the self-consistent method on supposing both the Poisson’s ratio of coarse aggregate and mortar matrix are 0.3,the results of prediction is more precise since the error is between -1%~4%.