Combined e ect of silica fume and polypropylene ber on drying shrinkage properties of concrete compositescontaining y ash

A parametric experimental study has been conducted to investigate thecombined eect of silica fume and polypropylene ber on the workability and dryingshrinkage of concrete composite containing y ash. four contents of y ash, four silicafume contents and four dierent ber volume fractions were used. the results indicatethat y ash can not only improve the workability but also lower the drying shrinkage of theconcrete composite. the workability of the concrete composite becomes better and betterand the drying shrinkage strain is decreasing gradually with the increase of y ash content.besides, silica fume has adverse eect on both of the workability and drying shrinkageproperty of concrete composite containing y ash. with the increase of silica fume content,both the slump and slump ow of the concrete containing y ash decrease gradually, whilethe drying shrinkage strain has an increasing tendency. in addition, polypropylene bercan greatly restrict the drying shrinkage of concrete composite containing y ash and silicafume, and there is a tendency of decrease in the drying shrinkage strain with the increaseof ber volume fraction. however, polypropylene ber has a little adverse eect on theworkability of concrete composite.