A Study of the Effect of Combined Cement and Fibre on Shear Strength Response of Chlef Sand

Abstract Soil reinforcement remains a vital task of a geotechnical engineer. There are a few support strategies for counting sands considered in this field that are strengthened by combined hydraulic binder (such as cement) and/or fibres. The behaviour of such mixtures (sand–cement and sand–cement–fibre mixtures) in terms of direct shear response has been subject to a lot of controversy in the literature. The base material used in the framework of this study is Chlef sand (taken from Chlef Valley, Algeria), mixed with cement and reinforced with synthetic fibres and considering the use of a direct shear device. , mixed with cement and reinforced with synthetic fibres. The types of fibres in terms of the materials used in the manufacture as well as their length and physical characteristics can improve the stress/strain response of sands. Laboratory results show that the shear strength response of sand–cement mixture increases the shear strength of this last and that it was observed with the addition of cement to the sand. The tests done on the mixtures of sand and cement and on fibre-reinforced mixtures showed better strength compared with just sand or cemented sand alone. Adding fibre to the mixture improved the soil’s ability to withstand shear forces. As the threshold value, the fibre content should be at least 0.15% in order to make a noticeable improvement in the mechanical properties. This increase in shear strength is noticed accompanied by a limitation in the samples’ contractiveness.