Browsing by Author "Aribi, C."

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A comparative study of the creep behavior of laminated composites : effect of type of fiber and matrix
(Academic Journals, 2017) Basaid, D.; Aribi, C.; Kari, J.; Benmounah, A.; Safi, Brahim
This paper presents the effect of matrix type on creep behavior at 80% loads of ultimate tensile strength of two laminated composites at different fiber and matrix system. For this, two types of laminated composites were manufactured based on two types of fibers (carbon fabric and glass fabric) with different matrix systems EPOCAST 50-A1 (EP50-A), Epoxy STR (STR) and Epoxy INJ812 (INJ). The tensile and creep behavior of each laminated composite was studied in the same test conditions. A microstructural study was also investigated by SEM-microscopy on the morphology of composite specimens after creep rupture failures at 80% of applied load. The obtained results showed clearly the influence of matrix type used on the tensile and creep behavior of studied composites. Indeed, it was noted that no creep rupture failures were observed in short-term (less than 4 h) for INJ/Carbon composite at tensile creep tests at 80% loads of ultimate tensile strength. At the same ultimate tensile strength, EP50/Carbon composite showed a best creep behavior up to 30 h and had a creep modulus higher than other laminated composites. The observation of rupture facets of all composite samples showed clearly that the rupture will take place in the direction of loading, creating voids at the interface resin/fiber. These are observed based on the nature of the matrix used
Effect of size and stacking of glass fibers on the mechanical properties of the fiber-reinforced-mortars (FRMs)
(2011) Saidi, M.; Safi, Brahim; Benmounah, A.; Aribi, C.
In modern day construction practice, repair and rehabilitation of structures have taken a prominent role. Indeed, the recent trend of rehabilitating and strengthening unreinforced masonry reinforced with glass fibers. In this paper, the use of fiber-reinforced-mortars (FRMs) is proposed for construction rehabilitation and reconstruction applications. A single type of fiber (glass fiber) with different length is considered; short, long and mixed. Several specimens mortars reinforced with fibers are tested in compression and flexure. Also, the stack and the microstructure of the interface glass fibers-matrix cementitious of the reinforced specimen, was examined. The results showed a remarkable increase in the mechanical resistances (50%), an important reduction of the brittleness of the reinforced mortars (lengthening higher than 40%) and a good ductility. That made it possible to increase considerably the safety of our constructions with a better esthetic aspect
Experimental study for the choice of a matrix epoxy resin for the elaboration of laminates
(2013) Aribi, C.; Bezzazi, B.; Mir, A.
The performances of composite materials are influenced by the properties of the matrix used. The latter ensures the desired form and the protection of the reinforcements against the external attacks. This work comprises a comparative study between laminates developed with different matrices in epoxy resin. Their characterization has to choose the best matrix able to give best results in static and dynamic tests. The resins used are provided by Granitex Algéria and which are primary Médapoxy STR resins, Médapoxy inject 812 and Médapoxy Al resin. Hence, the results of tensile tests prove a fragility of the AL resin which influences the maximal constraint of traction compared to the STR primary resin. Furthermore, Inject 812 resin shows very limited mechanical properties due to the changes of the epoxy network with the addition of diluents which has significantly decreased its viscosity
Experimental study of sandwich multilayer reinforced by glass fibre and agglomerated cork
(2014) Hami, Brahim; Irekti, Amar; Aribi, C.; Bezzazi, B.; Mir, A.
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 en¬vironment. 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
Fatigue behaviour of the laminates jute/epoxy
(2013) Mir, A.; Aribi, C.; Bezzazi, B.
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
The fatigue flexural behavior of fiber reinforced concrete : effect of the parameters of coarse aggregates
(Academic Journals, 2015) Dilmi, Hamid; Aribi, C.; Safi, Brahim; Bezzazi, Boudjema; Saidi, M.
The effect of the coarse aggregate type on the fatigue flexural behavior of concrete was investigated in this work. Three types of the coarse aggregates were selected from three different careers (CA1, CA2 and CA3). The mechanical parameters of these aggregates were determined (Los Anglos and Micro Deval). Prismatic specimens (70×70×280 mm) for each concrete mixture were made with aggregates of each source. The flexural fatigue tests were conducted on these concrete samples with varying levels of loading of 55 to 80% and the ultimate flexural strength. The test frequency is around 80 Hz and it is automatically determined by pulsing the fatigue machine for a resonance situation (the phase shift is δ=0) between the mass-spring-specimen system. The obtained results show that the aggregates which have the similar parameters (Micro Deval and LA), provide better adhesion with cement paste, and therefore a greater bending strength. The strength evolution at short-term age is typical for specimens based on aggregates with low wear resistance by triturate (a high Micro Deval coefficient). Regarding the fatigue flexural behavior, the concrete specimens based on CA1, which have similar coefficients of Los Angeles and Micro Deval (respectively 18 and 16) present the behavior (load/cycle numbers) close to that of the model prototype of the Wöhler curve. This can be explained by a high homogeneity of the charge distribution during fatigue test compared to other concrete mixtures. Also, it was noted that the relationship between the endurance limit and the coefficient of Los Angeles is inversely proportional: The aggregates which have good strength to fragmentation (low coefficient of LA), as aggregates CA2 case give an endurance limit at around 70% max bending load
Inspection of laminated composite materials by two ultrasonic techniques
(University of M’HAMED Bougara Boumerdes, 2013) Halimi, Rafik; Bezzazi, B.; Badidibouda, A.; Aribi, C.; Satour, A.
This paper presents some ultrasonic methods to detect and to characterize defects, possibly obtained after damage caused in composite materials. Firstly, artificial defects are located by two piezoelectric transducers. A two-dimensional ultrasonic cartography C-scan, performed section by section, at different positions which took part through the thickness of a carbon fiber-reinforced plastic composite beam, to be analyzed. Next, fundamental symmetric S0 mode of Lamb waves is used to measure the size of the delamination by scanning over the surface beneath which a delamination lies. A remarkable decrease in the arrival time due to the delamination is detected, and the delamination length can be calculated based on a simple model for Lamb-wave propagation. Furthermore, the delamination edge is located as a sudden decrease in the amplitude. The rate of decrease in amplitude of an individual pulse cycle was detected to vary with the depth of the delamination, being most sensitive to delaminations near the surface of the plate. This is particularly useful when sizing for defects close to the surface, where a normal-incidence pulse-echo ultrasonic method has problems, particularly when the depth of the defect or the back-wall echoes lie within the length of the transmitted ultrasonic pulse. The technique has potential for faster c-scanning of a complete plate than the usual normal-incidence pulse-echo method
Multilayer system of thermosetting polymers and specific confining : application to the walls of the hospital unit
(Photon Excellence Award-2014 : The Journal of Materials Science, 2014) Bouzid, Mohammed; Djadi, A.; Aribi, C.; Irekti, Amar; Bezzazi, B.; Halouene, F.
The nature of materials structuring our health institutions promote the development of germs. The sustainability of nosocomial infections remains significant (12% and 15%). One of the major factors being the portland cement which is brittle and porous. As part of a national plan to fight nosocomial infections, led by the University Hospital of Blida, we opted for a composite coating, application by multilayer model, composed of epoxy-polyester resin as a binder and calcium carbonate as mineral fillers. The application of composite materials reinforce the wall coating of hospital units and eliminates the hospital infectious areas. The resistance to impact, chemicals, raising temperature and to a biologically active environment, gives satisfactory results
Rheological behavior of the epoxy resin loaded with the pozzolan
(2012) Irekti, Amar; Hami, Brahim; Aribi, C.; Bezzazi, B.; Briki, I.
The study is to synthesize composite materials with news formul ations of thermosetting matrices by the incorporation of 40% of mineral fillers to reduce the cost of composite materials an d to improve implementation by increasing the viscosity and redu cing the withdrawal to its minimum value. The mineral filler increases si gnificantly in rheological parameters, whatever it nature of th e mineral filler. Compared to the control without charges, an increase of 60% of the shear stress and that of plastic viscosity were reco rded for the epoxy resin. The software Rheowine viscometer enabled us to m odel and identified the rheological behavior of these mixtures wit h resin. The results obtained in this modeling, confirmed that th e resin mixtures have shear-thinn ing rheological behavior, this last allows the model of the Ostwald de Waele
Static and cyclic behavior of concrete reinforced with materials composite
(Université M'Hamed Bougara Boumerdes, 2013) Irekti, Amar; Hami, B.; Aribi, C.; Abadlia, Mohamed Tahar
This work includes the test results of static and cyclic compression specimens of plain concrete and reinforced by several folds of woven fiberglass. The static compression tests were performed at a constant speed with gradual increase of the load. The results are expressed by curves representing the change of stress as a function of the strain to failure. The results give us three phases of behavior: a phase behavior similar to that of a homogeneous and elastic material resulting in an almost linear relationship between stress and strain. The second phase of development of shattered concrete that leads to progressive curvature of the curve until the maximum stress (σmax) for a certain amount of strain (ε), and third in imposing increases distortion, we can get a decreasing curve corresponding to the accentuation of the rupture, that is to say in the development of fracture surfaces and cracking more or less widespread. The cyclic compression tests were conducted under load imposed on a percentage of the maximum load in static fracture, with a change in the number of cycles for each set of specimens. The results of cyclic compression tests show that the loss of stiffness to failure of the specimen is divided into three phases: in the first phase shows a gradual reduction of stiffness in the early rounds in the second phase decreased rigidity becomes slow, and finally in the third phase, the loss of stiffness abruptly accelerates to failure of the specimen
Study of the green composite Jute/Epoxy
(2014) Mir, A.; Aribi, C.; Bezzazi, B.
Work presented is interested in the characterization of the quasistatic mechanical properties and in fatigue of a composite laminated in jute/epoxy. The natural fibers 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 fiber composites reinforced, even after several recycling. Because of the environmental standards that become increasingly severe, one attends the emergence of eco-materials at the base of natural fibers such as flax, bamboo, hemp, sisal, jute. The fatigue tests on elementary vegetable fibers show an increase of about 60% of the rigidity of elementary fibers 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
Tension fatigue behavior of the laminates jute/epoxy
(2013) Mir, A.; Aribi, C.; Bezzazi, B.