混杂粗纤维增强混凝土力学特性试验研究

选用低弹粗合成纤维、高弹钢纤维，以总体积掺率为1．5％的二元混杂纤维增强混凝土，系统研究了其弯曲韧性、抗弯冲击及断裂性能；用数理统计方法对抗弯冲击强度进行了分析；基于美国ASTM及日本JSCE方法，提出了适合评价粗纤维混凝土弯曲韧性的新方法。试验结果充分体现了粗合成纤维与钢纤维良好的协同效应；纤维混杂比例影响混杂纤维混凝土的性能，当粗合成纤维与钢纤维以体积掺率分别为1．0％、0．5％混杂时，纤维混凝土的各项力学性能达到优化，相对剩余强度、冲击延性指标、断裂韧度约分别达到79．6%、7．4、1．2。

Experimental study on mechanical properties of hybrid macro-fiber reinforced concrete

In this paper, hybrid fibers including low elastic modulus synthetic macro-fibers, high elastic modulus steel fibers as tow elements are used to been reinforcement in cementitious matrix. The volume fraction is 1.5%. The properties of flexural toughness, flexural impact, and fracture performance are investigated systematically. Flexural impact strength is analyzed with statistic analyses method. Based on ASTM and JSCE method, a new flexural toughness evaluating method suitable for macro-fiber reinforced concrete is first proposed. The results indicate that synergistic effect between synthetic macro-fiber and steel fiber is good. Fiber hybrid proportion has effect on mechanical performance of hybrid fiber reinforced concrete, when volume fractions of synthetic macro-fiber and steel fiber are respectively 1.0 % and 0.5 %, the mechanical properties of HFRC is achieved optimization, relative residual strength, impact toughness index, and fracture toughness are respectively 79.6%, 7.4, and 1.2.