No abstract

This study presents the effect of incorporating synthesized metakaolin on the compressive strength of standard mortars for a constant water/binder ratio of 0.5. Synthesized metakaolin mixtures with cement replacement of 5, 10, 15 and 20% were tested. From the results, it was observed that 15 % replacement level was the optimum level in terms of compressive strength. Beyond 15 % replacement levels, the strength was decreased but remained higher than the control mixture. Compressive strength of 52 MPa was achieved at 15 % replacement. This investigation has shown that it is possible to produce high strength mortars using local kaolin.

The maintenance of flexible roads or roads at end of life service generates high quantities of reclaimed asphalt pavement every year. The reuse of these materials, considered for a long time as waste, allows a substantial saving in transport, energy, and maintains dwindling natural resources. Recycling of asphalt also helps to reduce inert waste storage volumes, and conserve valuable landfill space. The applicability of recycled asphalt was tested in laboratory, and asphalt mixtures containing 20%, 40% and 50% of reclaimed asphalt pavement (RAP) were designed. Marshall and Duriez tests have been performed on various formulations using paving grade bitumen and modified bitumen as binders, the latter contains a quantity of Styrene /Butadiene / Styrene (SBS) polymer. This investigation led to the conclusion that the performance of recycled asphalt mixture containing 20% of RAP is significantly closer to those obtained with virgin asphalt mixture without recycled materials. In addition, the use of SBS polymer improves the properties of recycled asphalt mixtures even with high amounts of reclaimed asphalt pavement.

This paper presents an experimental study which is determined the mechanical properties of a composite material sandwich multilayer developed in the laboratory of mechanics of materials and composites, Materials Research Unit, process and environment. This type of sandwich is composed of four layers laminated based on an epoxy resin reinforced by woven glass fibres and mast between which three plates of agglomerated cork with stacked alternately laminated layers. Specimens for bending tests three and four points were prepared from the multilayer sandwich panels. A first series of static three-point bending tests shows a clear difference in the fracture behaviour for materials, laminate and cork. These materials have undergone a large plastic deformation without rupture achieve full sandwich, with the onset of delamination between layers laminated material and cork. In order to determine the bending stiffness modules D, the shear modulus and flexural N and the shear modulus of the soul Ga, we conducted a second test campaign four points bending. As a result, we can develop a variety of white cork produced in Algeria in order to use it in the construction and automotive industries.

The use of superplasticizers in concrete production has become a common practice, especially when a high fluidity is required. On the other hand, the risk of segregation and the stability of these mixtures is ensured by the incorporation of a large volume of fine mineral additions. The present investigation is devoted to the study of the influence of three types of superplasticizers of different chemical compositions, namely: Combined Synthetic Polymers (CSP), Poly-Carboxylate Ether (PCE), and Modified Poly-Carboxylate Ether (MPCE) on the rheological behavior of self-compacting concrete (SCC) as well as on the mechanical properties at 3, 7, and 28 days of curing. Natural pozzolana (NP) and ground granulated blast furnace slag (GGBFS) were used as additions to stabilize the mixtures. The results revealed that the ether-based superplasticizer PCE gave the best workability and mechanical performance with low amounts (high efficiency). In addition, blast furnace slag promotes the obtaining of better properties whether in the fresh or hardened state compared to natural pozzolana.