纳米SiO_2混杂纤维混凝土力学特性试验研究

Experimental Research on Mechanical Properties of Nano-SiO_2 Hybrid Fiber Concrete

采用高速研磨搅拌加水掺法，制备出含不同质量分数的纳米SiO2混杂纤维（NSPF）混凝土，通过力学试验测得立方体抗压强度、劈裂抗拉强度、变形性能及冲击韧性。通过与钢纤维／聚丙烯二元混杂纤维（SPF）混凝土进行比较，NSPF混凝土的立方体抗压强度、劈裂抗拉强度、疲劳次数、弹性模量、初裂抗冲击次数和破坏抗冲击次数分别提高10．4%、24．1％、90．0％、3．3％、49．8％和46．1％，泊松比无明显变化。综合分析表明，纳米SiO2在SPF混凝土中的合理掺量处于1．0％～2．0％之间。

A new nano-SiO2 hybrid fiber （NSPF） concrete containing different amount of SiO2 nanoparticles has been prepared by high speed grinding and water doped method, which was carried out cube compressive strength laboratory test, splitting tensile strength laboratory test, uniaxial cyclic loading laboratory test and free falling hammer impact laboratory test. By comparing with the steel and polypropylene hybrid fiber concrete （SPF）, the cube compressive strength, the splitting tensile strength, the fatigue cycle number, the elastic modulus, the resistance number of initial cracking impact and the resistance number of failure cracking impact of NSPF concrete were increased by 10. 4%, 24. 1%, 90. 0%, 3.3%, 49.8% and 46. 1% respectively, and the Poisson＇s ratio has no apparent change. The comprehensive analysis shows that the reasonable dosage of nano-SiO2 in SPF concrete is between 1.0 %-2. 0 %.