Unit of Research Materials


Unit of Research Materials

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Oualit M.,Unit of Research Materials | Jauberthie R.,INSA Rennes | Rendell F.,Consultant Engineer | Melinge Y.,INSA Rennes | Abadlia M.T.,Unit of Research Materials
Urban Water Journal | Year: 2012

The aim of this study was to investigate the deterioration of concrete sewers and identify responsible factors; this investigation was a part of an ongoing asset evaluation for Rennes (France). The sewer studied was a 300 mm spun concrete pipe laid in 1992. Core samples (D 28 mm, L 40 mm) were taken from different areas of a pipe (invert, crown and side wall) and analysed to quantify the condition of the concrete and the extent of damage to the internal and external surface of the pipe. Physical and mechanical properties of the material were characterised. The depassivation of the concrete was measured by testing with a phenolphthalein solution. The study showed that in this particular case the external corrosion was extensive with minimal internal corrosion.It is proposed that the corrosion was possibly linked to the use of a contaminated backfill or organic acids in the ground water. Recommendations are proposed concerning the direction of future research. © 2012 Copyright Taylor and Francis Group, LLC.

Mir A.,Unit of Research Materials | Aribi C.,Agence Nationale Pour Le Developpement Of La Recherche University | Bezzazi B.,Unit of Research Materials
Advanced Materials Research | Year: 2013

Work presented is interested in the characterization of the quasistatic mechanical properties and in fatigue of a composite laminated in jute/epoxy. The natural fibres offer promising prospects thanks to their interesting specific properties, because of their low density, but also with their bio deterioration. Several scientific studies highlighted the good mechanical resistance of the vegetable fibre composites reinforced, even after several recycling. Because of the environmental standards which become increasingly severe, one attends the emergence of eco-materials at the base of natural fibres such as flax, bamboo, hemp, sisal, jute. The fatigue tests on elementary vegetable fibres show an increase of about 60% of the rigidity of elementary fibres of hemp subjected to cyclic loadings. In this study, the test-tubes manufactured by the method infusion have sequences of stacking of 0/90° and ± 45° for the shearing and tensile tests. The quasistatic tests reveal a variability of the mechanical properties of about 8%. The tensile fatigue tests were carried out for levels of constraints equivalent to half of the ultimate values of the composite. Once the fatigue tests carried out for well defined values of cycles, a series of static tests of traction type highlights the influence of the number of cycles on the quasi static mechanical behavior of the laminate jute/epoxy. © (2013) Trans Tech Publications, Switzerland.

Mehena O.,Unit of Research Materials | Raoul J.,INSA Rennes | Yannick M.,INSA Rennes | Tahar A.,Unit of Research Materials
Applied Mechanics and Materials | Year: 2012

The costs associated with the provision and maintenance of drinking water and wastewater infrastructure represents a significant financial demand worldwide. Maintenance costs are disproportionately high, indicating a lack of adequate durability. The aim of this paper is to study the degradation mode and the responsible factors of deterioration concrete pipe, used in the sewage's city of Rennes (France). Thus, samples taken from different areas of the pipe (Raft, medium and roof) were analyzed using investigation methods in order to illustrate the internal and external rate of damage, caused by effluents and ground. In addition, chemical and mineralogical changes recorded were identified using scanning electron micrographs (SEM). In this research program, chemical and mechanical studies were performed by measuring the compressive and splitting tensile strengths. A phenolphthalein indicator solution is app lied to a concrete specimen on a fresh fracture surface to determine the corrosion of steel reinforcement and the diseases advancement (pathologies depth). This study clearly shows the important anisotropy of both, internal and external damage. Finally, recommendations are proposed in line with the environment and possible app roaches to sustainability assessment are also imposed. © (2012) Trans Tech Publications, Switzerland.

Hami B.,Unit of Research Materials | Irekti A.,Unit of Research Materials | Aribi C.,Unit of Research Materials | Bezzazi B.,Unit of Research Materials | Mir A.,Unit of Research Materials
Advanced Composites Letters | Year: 2014

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.

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