No abstract

In this study, an alternative and environmentally friendly method for the reinforcement of dune sand is proposed. This technique consists of using randomly distributed rubber fibers to improve the engineering properties of sand. Rubber fibers are added to the sand with different percentages: 0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75 and 2% of dry weight of sand. The experimental program carried out consists of investigating the effect of rubber fibers on the shear strength properties of sand. Reinforced and unreinforced samples are tested in the dense as well as loose state. The results obtained showed that the inclusion of rubber fibers in dune sand will improve the engineering properties of various civil engineering applications such as shallow foundations and slope. Therefore, incorporation of rubber fibers can enhance the shear strength characteristics, peak and residual strengths, and introduce more ductility to the mechanical behavior of sand. In addition to the technical effect, this paper emphasizes another environmentally attractive option, which is the use of rubber fibers as reinforcements for granular soils as this helps to remove some parts of these wastes and protect the environment.

In order to study the behaviour of a roller compacted concrete (RCC) reinforced with polypropylene fiber, six types of RCC were made with different content of fibers (0, 0.5, 1, 1.5, 2 and 2.5 Kg/m 3 ). The physical parameters are the density, the workability, the shrinkage and the water absorption. For the mechanical parameters; the performances such as the compressive strength and the tensile strength (3 point bending and splitting) has been studied.The results show that the RCC reinforced with fibers present the better performances in terms of strength and physical behaviour. The results obtained show the positive effect of the polypropylene fiber addition on the mechanical strength, which increases about 23% for the mixture with 1 Kg/m 3 . For the physical properties, there is a decrease in the density and workability and an improvement in the water absorption proportional with the addition of polypropylene fiber. In addition, we conclude the positive effect of polypropylene fiber on the kinetics and development of the shrinkage. In this study, the best physical and mechanical performance was being observed in the mixture with 1 Kg/m 3 of polypropylene.

This study aims to analyze the possibility of valorizing rubber waste in roller-compacted concrete pavement (RCCP) mixes as aggregates. The rubber particles were added to the mix as partial replacement of the total volume of gravels at different rates (5, 10, 15, 20, 25, 30%). The experimental approach followed in this research consisted of studying the effects of the incorporated rubber on the mechanical properties of RCCP. The obtained results show that the incorporation of rubber changes the behavior of RCCP mixes. In presence of rubber, the RCCP became more ductile. The principal disadvantage of rubber incorporation was the decrease in the mechanical properties of RCC. To remedy this problem, the rubber particles were subjected to a treatment and silica fume was added to the mix. The obtained results showed that the performance of RCCP can be improved by modifying the surface roughness of rubber particles. Therefore, a large part of strength losses were corrected.

No abstract