Research on the disintegration performance of fibre-reinforced vegetative cement-soil (VCS)

Vegetative cement-soil (VCS) has been widely applied for the protection and ecological restoration of slopes with ratios less than 1:0.5 in China. However, disintegration and shedding problems have occurred in projects in heavy-rainfall areas. Herein, fibre reinforcement was performed to improve the anti-disintegration performance of VCS. The disintegration characteristics, microstructures, and pore structural characteristics of VCS and RVCS (Reinforced vegetative cement-soil) and the effects of three kinds of fibres (PF, BF, CPF) at four different fibre contents (0.2 %, 0.4 %, 0.6 %, and 0.8 % VCS dry weight) on VCS anti-disintegration properties were studied. There are three main reasons for the strong disintegration of VCS: (1) high porosity provides more seepage channels; (2) the uneven distribution of hydrated cement and incomplete hydration reactions affect the reinforcing effect of cement on samples; and (3) decomposition of organic matter leads to large aggregate fragmentation. The component disintegration–fracture cycle leads to VCS disintegration. Fibre incorporation reduces the VCS disintegration ratio and rate and improves VCS anti-disintegration performance. A fibre content of 0.4 % is best, and the incorporation of greater or lesser amounts of fibre affects the fibre reinforcement effect. The anti-disintegration effect of the three fibres on RVCS was in the following order: CPF > PF > BF, and the differences in the anti-disintegration effect of the three fibres are attributed mainly to differences in fibre surface morphology, degree of bending, diversity in cross-sectional size, physicochemical properties, etc. • CPF-0.4 % is the best improvement scheme. • The disintegration process of VCS and RVCS can be divided into three stages. • R H has the greatest influence on the disintegration of VCS. • The decomposition of organic binders leads to the disintegration of VCS. • The cycle of dissociation and cracking leads to the disintegration of VCS.