Search

Current research in the field of building materials is oriented towards the recovery of waste to ensure the lightening of certain building elements and energy saving. The objective of this study is to produce a new bricks by adding sawdust to clay mixtures. The first part of this experimental work consists on detremining the proper manufacturing process and cooking diagram for these new bricks. In the second part, the effect of the maximum cooking temperature, the firing phase time's of the bricks and the sawdust prportion on the physical and mechanical properties of the new bricks have been studied. The studied properties are the absorption ratio, the unit weight and the compressive strength. The results showed that the addition of an increasing amount of sawdust tends to modify the physical and mechanical properties of the cooked samples. The presence of sawdust reduces the number of connections between the clay grains and produces a lighter, more absorbent and less resistant material. Finally, the results showed that the manufacture of bricks based on sawdust is possible.

In recent years, the durability of concrete has been the subject of a few research projects carried out by several scientific and technical centres. As a major cause of concrete degradation around the world, reinforcing steel corrosion requires our full attention. This article analyses one of the phenomena at the origin of these disorders, namely the carbonation of concrete, and proposes some provisions to guard against it. The article is divided into two parts; the first describes the causes and consequences of the chemical process of carbonation as well as the means to protect it. The second deals with the influence factors on carbonation such as the minimum cement dosage, the type of cement, the water-cement ratio (W/C) and the reinforcement coating. Indeed, prismatic specimens (15 x 15 x 60 cm³) and cubic specimens (15 x 15 x 15 cm³) were made for different mixtures and with a W/C ratio of 0.50, 0.55 and 0.60. The prismatic specimens were subjected to a carbonation test, while the cubic specimens were used to determine the compressive strength, the corresponding density and the immersion water absorption. [ABSTRACT FROM AUTHOR]

In this paper, an experimental study was carried out in order to provide more data on the effects of expanded perlite aggregate (EPA) dosage on the compressive strength and thermophysical properties of lightweight concrete at different ages. The first part of this experimental study was devoted to the choice of the proper mixing procedure for expanded perlite concrete (EPC). Thereafter, six sets of cubic specimens and six sets of parallelepiped specimens were prepared at a water-to-cement ratio of 0.70 with varying replacement percentages of sand by EPA ranging from 0% to 80% by volume of sand. Compressive strength, thermal conductivity and thermal diffusivity were determined over curing age. Unit weights for the mixtures prepared varied between 560 and 1510 kg/m³. Compressive strength was decreased when perlite content was increased. The test results indicated that replacing natural aggregate by EPA increased the thermal resistance of the lightweight concrete and consequently, improved thermal insulation. [ABSTRACT FROM AUTHOR]