混杂纤维延性水泥基材料单轴受压力学特性

Mechanical Properties of Hybrid Fiber Reinforced Engineered Cementitious Composites under Uniaxial Compression

关键词:  混杂纤维  单轴受压  应力应变曲线  韧性  泊松比

Key words:  hybrid fiber  uniaxial compression  stress strain curve  toughness  Poissons ratio

摘要:

针对纤维增强延性水泥基材料（ECC）在高强度等级下的抗压韧性退化问题，在传统ECC体系中附加微细钢纤维，制备混杂聚乙烯醇(PVA)钢纤维增强延性水泥基材料.通过圆柱体抗压试验研究混杂纤维延性水泥基材料的单轴受压力学特性.结果表明：随着钢纤维掺量的增加，材料受压应力应变曲线的上升段斜率呈增大趋势，而曲线下降段逐渐平缓，残余应力水平显著提升；混杂纤维延性水泥基材料的单轴抗压强度、弹性模量和峰值应变随钢纤维掺量增加小幅提升，而材料抗压韧性指标的提升效果较为显著；PVA纤维与钢纤维混杂在改善ECC抗压韧性方面具有独特优势，实现了高强ECC的抗压韧性.

Abstract:

In order to improve the compressive toughness of engineered cementitious composites(ECC) with high strength, hybrid polyvinyl alcohol(PVA) steel fiber reinforced ECC were developed by incorporating additional steel micro fibers into traditional ECC. Cylinder specimens were tested under uniaxial compression to investigate the mechanical properties of hybrid fiber reinforced ECC. Test results show that the ascending slope of stress strain curves is increased with the increasing addition of steel fibers，while the descending portion is gradually improved and leads to higher residual stress. The uniaxial compressive strength, elastic modulus and peak strain of hybrid fiber reinforced ECC are slightly increased respectively with the increasing additional steel fibers, while a significant improvement is achieved for compressive toughness. Hybrid PVA steel fiber system exhibits advantages over mono fiber system. ECC with both high strength and high compressive toughness are obtained.