纤维混杂对超高性能混凝土性能影响试验研究

Experimental study on the influence of fiber hybrid on the performance of ultra-high performance concrete

利用钢纤维、碳纤维及膨胀剂等制备超高性能混凝土,测试评估材料的工作性、力学性能、收缩和耐久性能及微观结构。研究表明,碳纤维替代钢纤维量1.0‰时工作性及力学性能最佳,28 d抗压与抗折强度可以达到182.9 MPa与60.9 MPa;膨胀剂4.0%掺量下效果较好,90 d膨胀率基本稳定在2?左右;水化产物微观结构致密,120 d碳化满足T-Ⅳ等级,抗硫酸盐等级大于KS60,动弹模量54.21 GPa,耐久性好。

Using steel fiber,carbon fiber and expansion agent are used to prepare ultra-high performance concrete,and the workability,mechanical properties,shrinkage,durability and microstructure of materials are tested and evaluated.The results show that the workability and mechanical properties are the best when the carbon fiber replaces the steel fiber by 1.0‰,and the 28 d compressive and flexural strength can reach 182.9 MPa and 60.9 MPa;The effect is better when the dosage of expansion agent is 4.0%,and the expansion rate is basically stable at about 2‰ in 90 days;The microstructure of hydrated products is dense,120d carbonization meets TIV grade,sulfate resistance grade is much higher than KS60,dynamic modulus is 54.21 GPa,and durability is good.