Physico-Mechanical Characterizations of Sand Concrete: Prestressed Beams and Hollow Bricks

The use of the sand concrete makes it possible to carry out a concrete having physico-mechanical properties answering the structural exigences and having economic and environmental advantages compared to the classical concrete. The present study aims to connecting the parameters of a formulation based on an empirical formula of Caquot in order to optimize, on the one hand the couple compressive strength/absorption of water under various degrees of hygrometry, and on the other hand more precisely to use the concrete sand in the public works sector in the prefabrication of prestressed beams and hollow bricks. The results show the importance of the type of formulation used because it takes into account the percentages of fillers of sand which is a co-product (waste) of massive rock crushing. In addition, the use of fillerized sands, which are wastes of crushing basaltic rocks and containing a small percentage of fillers, is efficient in the manufacture of prestressed beams. As for the hollow bricks, a fillerized basalt sand, containing a high percentage of filler, as well as a sand dune, gives satisfactory results.

Influence of Heat Exchange Coefficients on Both Optimized Thermal Contact (OTCR) and Critical (CTCR) Resistances at the Contact Interface of a Flat Concrete Slab and a Rice Straw Board

The study is carried out in imperfect contact with a concrete slab wall attached to a panel based on rice straw compressed in a dynamic frequency regime. We will propose the characterization of thermal insulation for thermal resistance of contact (x = 0.05 m). The impact of heat exchange coefficients on the front face (x = 0 m) and the rear face (x = 0.1 m) on these resistors is shown.