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In road construction, bitumen is the binder that gathers the different aggregates of road pavements. Bitumen, as a viscoelastic material, influences considerably the rheological behavior of bitumen concrete. The bitumen used in Algeria, shows its limits in facing the traffic, which is increasing continuously. This research aims to valorize Styrene-Butadiene-Styrene SBS polymer in wearing course by modifying a pure 35/50 bitumen. The present paper aims to study the polymer derived from styrene and butadiene (SBS) the company Kraton Polymers International Ltd for the modification of a bitumen to improve its mechanical characteristics. To this end, the incorporation of SBS polymer was carried out according to two contents: 5.0 and 7.5% (by weight of asphalt) to evaluate the influence of this type of polymer on the rheological properties of the bitumen ordinary road including viscosity and modulus. The results revealed that the bitumen modified with 7.5% of SBS has better mechanical performance on the rigidity and the elasticity compared to the conventional bitumen. Recommendations have been made to implement a bitumen modification system to improve its quality and therefore the durability of bituminous pavements in the south of Algeria. [ABSTRACT FROM AUTHOR]

The objective of this research is to evaluate the effects of soil-structure interaction (SSI) on the modal characteristics and on the dynamic response of structures. The stress had an impact on the overall behaviour of five storeys reinforced concrete (R/C) buildings typically encountered in Algeria. Sensitivity studies are undertaken in order to study the effects of frequency content of the input motion, frequency of the soil structure system, rigidity and depth of the soil layer on the dynamic response of such structures. This investigation indicated that the rigidity of the soil layer is the predominant factor in soil--structures interaction and its increases would definitely reduce the deformation of the R/C structures. On the other hand, increasing the period of the underlying soil will cause an increase in the lateral displacements at storey levels and create irregularity in the distribution of storey shears. Possible resonance between the frequency content of the input motion and soil could also play an important role in increasing the structural response. [ABSTRACT FROM AUTHOR]