论文部分内容阅读
为了研究聚丙烯纤维改良黄土的效果和机理以及改善灰土和二灰土的脆性破坏形式,在黄土、灰土和二灰土中随机掺入长度为10mm的聚丙烯纤维,试验中聚丙烯纤维的质量百分比为0.25%,分别养护7d、28d、90d后,进行无侧限抗压试验和直剪试验。试验结果表明:聚丙烯纤维的掺入增强了基质土的抗压、抗剪等力学性能,提高了应力峰值应变和残余强度,减小了破坏后的应力衰减速度,抑制了破坏裂缝的贯通发育。电子显微镜扫描(SEM)结果显示,随机离散分布的聚丙烯纤维作为空间三维网络,通过胶结和摩擦作用联锁土壤颗粒和胶结凝块,形成一个统一的相干框架结构,提高了改良黄土的结构强度。
In order to study the effect and mechanism of polypropylene fiber to improve loess and to improve the brittle failure mode of limestone and lime-flyash, polypropylene fiber with length of 10mm was randomly mixed into loess, lime soil and lime-flyash soil. The mass percentage of polypropylene fiber 0.25%, respectively, conservation 7d, 28d, 90d, unconfined compression test and direct shear test. The experimental results show that the incorporation of polypropylene fiber enhances the mechanical properties such as compressive strength and shear resistance of matrix soil, increases the stress peak strain and residual strength, reduces the rate of stress decay after failure, and inhibits the through development of damaged fractures . Scanning electron microscopy (SEM) results showed that randomly dispersed polypropylene fibers, as a three-dimensional space network, interlocked soil particles and cementitious clinker through the action of cementation and friction to form a unified coherent frame structure and improved the structural strength of the improved loess .