五种外加剂对混凝土早期开裂性能的影响

Effect of Five Additives on Early Cracking Performance of Concrete

为研究不同外加剂对混凝土早期开裂性能的影响,通过在混凝土材料中掺入硅灰、粉煤灰、矿渣、棉纤维和聚丙烯纤维等五种外加剂(掺量均分别为1%、2%、3%、4%、5%)来研究混凝土早期裂缝成型时间和裂缝长度。结果表明,掺加纤维类外加剂能够有效减缓混凝土早期裂缝的形成,且掺量越大效果越好,可在混凝土中掺入5%的棉纤维或聚丙烯纤维来降低混凝土早期裂缝对结构安全的影响。研究成果可为高性能混凝土的设计提供参考。

In order to study the influence of different admixtures on the early cracking performance of concrete,five admixtures(1%,2%,3%,4% and 5%respectively)including silica fume,fly ash,slag,cotton fiber,and polypropylene fiber were added into concrete materials to study the forming time and crack length of early cracking of concrete.The results show that the fiber admixtures can effectively slow down the formation of early cracks in concrete,and the greater the dosage is,the better the effect is.It is safe to add 5% cotton fiber or polypropylene fiber into concrete to reduce the early cracks in concrete.The research results can provide references for design of high performance concrete.