纤维聚苯乙烯泡沫颗粒轻质土的制备及力学性能

发布时间：2018-10-18 16:10

【摘要】：为促进轻质土在岩土工程中的广泛应用,添加改性聚丙烯纤维改善其力学性能,通过无侧限抗压强度试验分析探讨了纤维聚苯乙烯泡沫(EPS)颗粒轻质土强度-变形特性、受压破坏模式和无侧限抗压强度的影响因素,并运用SEM从微观层次上分析了其力学机制。结果表明:不同EPS颗粒、纤维及水泥掺量时,纤维EPS颗粒轻质土的应力-应变曲线不同;EPS和水泥掺量是强度的主要影响因素,其次为纤维掺量;强度随EPS掺量的增大而显著降低,随水泥掺量增大而显著提高;未加纤维的EPS颗粒轻质土松散且易破碎,强度骤然丧失;添加纤维能提高轻质土的峰值强度、残余强度、整体性和韧性,改善其脆性破坏模式;但EPS掺量较高(大于干土质量的3%)时,纤维与水泥土粘结有限,EPS颗粒轻质土力学性能改善效果较弱;EPS颗粒为空心蜂巢结构,纤维表面布满针状的水泥水化物并形成空间网状结构。所得结论表明纤维改善了轻质土力学性能。
[Abstract]:In order to promote the wide application of lightweight soil in geotechnical engineering and to improve its mechanical properties by adding modified polypropylene fiber, the strength and deformation characteristics of lightweight soil with fiber polystyrene foam (EPS) particles were analyzed through unconfined compressive strength test. The influence factors of compressive failure mode and unconfined compressive strength are analyzed by SEM. The results show that the stress-strain curves of lightweight soil with different EPS particles, fiber and cement content are different, the content of EPS and cement is the main influence factor of strength, the second is fiber content. The strength decreased significantly with the increase of EPS content and increased with the increase of cement content. The strength of EPS granular lightweight soil without fiber was loose and easily broken, and the strength was suddenly lost, and the peak strength and residual strength of light soil were increased by adding fiber. When the content of EPS is high (more than 3% of dry soil mass), the bond between fiber and cement soil is limited, the improvement effect of light soil mechanical property of EPS particle is weak, and the EPS particle is hollow honeycomb structure. The surface of the fiber is covered with needle-like cement hydrates and forms a spatial network structure. The results show that the fiber improves the mechanical properties of light soil.
【作者单位】：中国地质大学生物地质与环境地质教育部重点实验室;
【分类号】：TB332

【相似文献】