Hu Q Z, Chen Y Y, Zhuang X S,et al.Experimental study on the physical and mechanical properties of polypropylene fiber-reinforced lightweight soil[J].Journal of Henan Polytechnic University(Natural Science) ,2026,45(6):167-174.

doi:10.16186/j.cnki.1673-9787.2024060006

Received:2024/06/05

Revised:2024/08/29

Published:2026/10/09

Experimental study on the physical and mechanical properties of polypropylene fiber-reinforced lightweight soil

Hu Qizhi1,2, Chen Yuyi1, Zhuang Xinshan1,2, Liu Yiming1,2, Tao Gaoliang1,2

1.School of Civil Engineering， Architecture and Environment， Hubei University of Technology， Wuhan  430068， Hubei， China；2.Hubei Engineering Research Center for Bridge Safety Monitoring Technology and Equipment， Wuhan  430068， Hubei， China

Abstract: Objectives To improve the crack resistance and failure behavior of lightweight soil， an experimental study on the physical and mechanical properties of polypropylene fiber-reinforced lightweight soil was conducted.  Methods Polypropylene fiber content， EPS （expandable polystyrene） particle content， and cement content were selected as three influencing factors， with four levels assigned to each factor. An L16（4³） orthogonal experimental design was adopted to obtain 16 combinations. Unconfined compressive strength tests and density tests were performed on lightweight soil specimens with different factors and levels. The effects of different factors and levels on the properties of lightweight soil were investigated through range analysis and analysis of variance （ANOVA）. The effects of polypropylene fiber and EPS particle contents on the failure characteristics of lightweight soil under unconfined compression were analyzed， and the mechanical properties were further examined at the microscopic level using scanning electron microscopy （SEM）.  Results The results showed that the factors affecting the strength of lightweight soil followed the order of cement content， EPS particle content， and fiber content， while the factors affecting density followed the order of EPS particle content， cement content， and fiber content. The density and unconfined compressive strength of lightweight soil increased significantly with increasing cement content but decreased with increasing EPS particle content. The addition of polypropylene fiber effectively improved the strength and crack resistance of lightweight soil and provided certain residual strength. However， when the fiber content exceeded the optimum value， the strength of lightweight soil began to decrease. Conclusions The results provide a theoretical basis for improving the physical and mechanical properties of polypropylene fiber-reinforced lightweight soil and offer valuable references for its practical engineering applications.

Key words: polypropylene fiber; lightweight soil; orthogonal test; unconfined compressive strength