Treatment of an expansive soil using vegetable (DISS) fibre

This paper presents the study of treatment of an expansive soil with vegetal fibres. The soil studied is swelling clay from the region of Souk Ahras (Algeria). The use of fibres as reinforcement has shown a certain efficiency which increases the bond between the soil grains due to the friction between the soil particles and the fibre material. The vegetal fibres used are DISS crushed fibres. The influence of the vegetable fibre content on the global behaviour of the soil is studied; by highlighting the role of the inclusion rate of fibre in the soil mass (1, 2 and 3% of content by weight), this will be studied by a series of behaviour and mechanical performance tests. The DISS fibres have undergone chemical-thermal treatment to extract the sugars and soluble substances contained in the vegetal to avoid the decomposition of the latter in the soil. The results will be compared to those of unreinforced soil. Experimental results show that the swelling potentials are reduced by the addition of vegetal fibres, the cohesion of the soil treated is increased, and the soil is more ductile. It has also been shown that 2% of the DISS fibre content is a critical value for reducing the swelling potential of the clay soil.