Youcef Bouafia

Université Mouloud Mammeri de Tizi Ouzou | UMMTO · Department of Civil Engineering

This study aims to experimentally evaluate the mechanical properties of concrete slabs reinforced with two types of fibers: metallic fibers (MF) and grids based on polypropylene fibers (PPG). The metallic fibers, sourced from machining waste of steel parts, are randomly distributed in the concrete, while the polypropylene fibers are arranged in gri...

Recently, there are many studies of the nonlinear structural analysis. This paper presents the method to predict nonlinear response structures. A numerical approach is proposed for the nonlinear analysis structures problems using displacement method. The formulation is based on the rope stiffness matrix of the beam element, which is presented takin...

Masonry is widely used around the world, primarily due to its exceptional thermal and sound insulation properties, which make it an indispensable component in the field of construction. This study focuses on evaluating the compressive strength of masonry. By gathering and analyzing a comprehensive dataset of experimental tests from various sources...

This study evaluates the performance of concrete under the effect of the addition of non-straight fibers recovered during the machining of steel parts and then studies the effect of the addition of corrugated fibers (chips) on their behavior in direct traction of the fiber concrete. In order to characterize the mechanical behavior and tearing of th...

This paper describes a study of recycled concrete under compressive loads. The study was conducted in two main parts. In the first part, experimental tests were carried out on concrete samples with varying levels of substitution (25%, 50%, and 75%) with recycled aggregate in order to measure the mechanical properties of the recycled concrete. In th...

Reinforced concrete frames with masonry infill are widely utilized in construction worldwide. This present study aimed to investigate the behaviour of masonry infill. Firstly, the compressive strength of the masonry infill and the evaluation methods were examined, specifically prism tests and wallette tests. The study collected a substantial databa...

Les murs de remplissage en maçonnerie ont longtemps été négligés dans la conception et le dimensionnement des structures auto-stables en béton armé. Les rapports post-sismique ont permis de mettre en avant l’influence de ces derniers et leur importance dans le comportement des structures auto-stables, lors des séismes de Chlef en 1980 et Boumerdès...

The purpose of this study, is to deals with capacity design (strong column – weak beam) in reinforced concrete frames, slightly slender, which depends on the determination of a capacity ratio necessary to reach a structural plastic mechanism. To find the capacity ratio allowing to achieve a fairly ductile behavior in reinforced concrete frames, it...

In this paper, we present an analytical model to analyze reinforced and prestressed concrete beams loaded in combined bending, axial load and shear, in the frame of non linear elasticity. In this model, the equilibrium of the beam is expressed by solving a system of equations, governing beams equilibrium, based on the stiffness matrix of the beam,...

Understanding the behavior of recycled aggregate concrete (RAC) requires a multiscale analysis to take into account the influence of new particles, the recycled aggregates (RA), in their preparation The overall behavior of recycled aggregate concrete is obtained by a three step homogenization strategy. Several analytical homogenization methods will...

In this article, we present a numerical model allowing to simulate the behavior until failure of isostatic and hyperstatic composite (steel–concrete) beams with an external prestressing system, taking into account the diferent arrangements of the cables located under the deviators. In this numerical calculation model, the external prestress is mode...

The calculation and design of the structures are carried out with the aim of obtaining a sufficiently ductile behavior to allow the structure to undergo displacements, without risk of sudden breaks or loss of stability. The purpose of this study is to develop and validate a computer program (Thin beam2), allowing the modeling and simulation of the...

This work deals with the coupling between a periodic homogenization procedure, and a damage process occurring in a Representative Volume Element (RVE) of inclusion composite materials. We mainly seek, on the one hand to determine the effective mechanical properties according to the different volume fractions, and forms of inclusions for a composite...

ABSTRACT. This work deals with the coupling between a periodic homogenization procedure, and a damage process occurring in a Representative Volume Element (RVE) of inclusion composite materials. We mainly seek, on the one hand to determine the effective mechanical properties according to the different volume fractions, and forms of inclusions...

The object of this article is to be able to simulate the behavior of reinforced and/or prestressed concrete beam’s section in the shear loading through a model allowing the evaluation of nonlinear strains caused by shear, while taking into account the real behavior of the materials. In this approach, we are often confronted with problems of modelin...

The object of this article is to be able to simulate the behavior of reinforced and/or prestressed concrete beam’s section in the shear loading through a model allowing the evaluation of nonlinear strains caused by shear, while taking into account the real behavior of the materials. In this approach, we are often confronted with problems of modelin...

Numerical simulation of simple and composed bending behaviour of reinforced concrete spatial structure elements with circular cross section in the field of nonlinear elasticity, require a particular modeling’s technique of the cross section shape by a subdivision of the latter into trapezoids to best approximate the contour of the cross section. Th...

Numerical simulation of simple and composed bending behaviour of reinforced concrete spatial structure elements with circular cross section in the field of nonlinear elasticity, require a particular modeling’s technique of the cross section shape by a subdivision of the latter into trapezoids to best approximate the contour of the cross section. Th...

Composite steel–concrete structures are commonly used in the field of bridges, where the steel frame provides great ease of installation, and concrete provides useful strength at low cost. This construction system makes it possible to seek to use each material to the best of its ability, so as to provide the entire construction system with greater...

Abstract Understanding the behavior of recycled aggregate concrete (RAC) requires a multiscale analysis to take into account the influence of new particles in their preparation, the recycled aggregates (RA). The overall behavior of RACs is obtained by a three step homogenization strategy. The effective properties of the recycled aggregates are at...

The main objective of this article is to apply a simplified model to simulate the overall behavior of a reinforced concrete wall without the need to explicitly represent the reinforcing bars in the model nor the progressive degradations of the concrete in tension. The model takes into account the fictitious laws of the material, in order to estimat...

A new model is introduced, for predicting the nonlinear behavior of the concrete until the rupture. The non-linear behavior of the concrete is taken into account under monotonic load verifying the principles of the mechanics damage [1] and the concepts of the mechanics of the fracture, using the foundations of the continuum mechanics of materials [...

This study presents the results of a new approach for structural reliability analyses using adaptive kriging, confirmation simulation, and the pilot point method. Its main objective is to develop an efficient and accurate global approximation while controlling the computational cost and accuracy of prediction. The main contribution of research is t...

The present study goes into the search for the safety domain of civil engineering structures. The objective is to show how a reliability-evaluation brought by a mechanical sizing can be obtained. For that purpose, it is necessary to have a mechanical model and a reliability model representing correctly the behavior of this type of structure. It is...

The aim of this paper is to study the reinforced concrete short tie-rods behavior using the adhesion-slip curve shape between steel and concrete adopted by the European Concrete Committee. We are interested here in short tie-rods without main cracks for which we calculate and measure the maximum mobilization state of steel-concrete adhesion, and be...

The purpose of this study is to determine the mechanical characteristics by homogenization methods; Firstly, it involves modeling using the semi-analytical method (Mori-Tanaka and Auto-coherent model), then applying the periodic homogenization method and in particular, the asymptotic method for a representative volume element (RVE) of a composite "...

This work joins in the context of the recovery of waste production "chips" of steel parts that are found in the industry, cementitious matrix is a means for recycling this type of materials, and indeed these chips play the role of corrugated metal fibers. The presence of these chips in a cement matrix they used, to give the resulting composite duct...

Under the effect of the ascending loading, the behavior of reinforced concrete structures is rather non linear. Research in industry and science aims to extend forward the use of non-linear calculation of fiber concrete for structural parts such as columns, veils and pious, as the fiber concrete is more ductile behavior then the classical concrete...

The present work were the efficiency and mechanism of stabilization/solidification of ultimate inorganic waste (hydroxides and metal fibers sludge), in cement matrix. This waste, characterized by the standard toxicity characteristic leaching procedure (TCLP) test, showed that the concentrations (mg/kg) of heavy metals were: Ni 2+ = 384.9, Cr 3+ = 8...

The objective of this work is to determine the impact of the temper heat treatment (150, 160, 170, 180, 190, 200,220 and 240) °C on the evolution of the main elastic and structural properties of the alloy foundry AlSi7Zn3Cu2Mg (42500). This alloy will be subjected to precipitation hardening. This is one of the most successful methods to considerabl...

The objective of this study is to analyse the reliability of three-dimensional reinforced concrete structures in which the non-linear mechanical and geometric nonlinearity are takeinto account. For this purpose, we have developed a program in FORTRAN to simulate the direct Monte Carlo method coupled to a non-linear calculation for evaluating the fa...

This work deals with the experimental study of the mechanical behavior by three-point bending tests and shear (fracture shear) of concrete beam elements reinforced by long fibers. These fibers come from machined steel parts waste. Bending and shear tests are conducted on prismatic specimens [10 × 20 × 120] cm³. Compressive strength tests are carrie...

Abstract As part of this study, has been developed a numerical method which allows to establish abacuses connecting the normal force with bending moment for a circular section and therefore to predict the rupture of this type of section. This may be for reinforced concrete (traditional steel) or concrete reinforced with steel fibers. The numerical...

ABSTRACT An analytical model is presented for predicting complete shear load-deformation response of reinforced concrete sections taking into account the steel fibers reinforced concrete. This model is based on the equilibrium, compatibility equations and stress-strain relationships which are formulated in term of average stresses and average strai...

As part of this study, has been developed a numerical method which allows to establish abacuses connecting the normal force with bending moment for a circular section and therefore to predict the rupture of this type of section. This may be for reinforced concrete (traditional steel) or concrete reinforced with steel fibers. The numerical simulatio...

This study focuses on the influence of the variation of maturing time, addition of Mg and elaboration mode on the evolution of mechanical properties (strength, ductility) and microstructural properties of the unstandardized foundry alloy AlSi13Mg. It is then determined favorable maturation time (the variation of the maturing time is performed in in...

In this paper, the punching shear resistance of slabs is numerically evaluated and compared to predictions specified in some design codes. The interaction of major parameters that affect the punching shear behaviour and failure mode of slabs is also studied. Reliability analysis results are presented in terms of the reliability index for various le...

The aim of this study is to investigate the earthquake damage response of the concrete gravity dam. It is well known that simulation of concrete structures up to rupture requires nonlinear behavior of the models. The material behavior whose principle is based on the damage mechanics has been implemented in a finite element program. Thismodel takes...

The damage mechanics allows a detailed modeling of reinforced concrete’s degradation phenomenon. The theory of isotropic damage leads to quite satisfactory results in the description of both in the local and the global behavior. It is within the scope of this work to provide a model of damage based on the non-linear mechanical behavior of fiber con...

In this paper, we present an analytical model to analyze reinforced and prestressed concrete beams loaded in combined bending, axial load and shear, in the frame of non linear elasticity. In this model, the equilibrium of the beam is expressed by solving a system of equations, governing beams equilibrium, based on the stiffness matrix of the beam,...

This work carries an experimental study on the composition and the characterization of the self-compacting concretes made starting from waste of construction with comparisons which were made by contribution with the vibrated concrete. Studies on the workability and the compactness of material were made and this in a fresh state and a hardened state...

The present paper deals with a numerical computation using finite element method for concrete structures subjected to dynamic loads, usually of seismic nature the consequences of which are often devastating. In the general equation of dynamic, a law of concrete material behavior taking into account models based on the damage mechanics has been impl...

We propose in this work a model for monitoring the behavior of non-linear elasticity of concrete in both compression and tension until the break. This model is determined by applying the principles of damage mechanics and fracture using the actual laws of nonlinear behavior usually admitted in the continuous mechanics of materials (Sargin relations...

An analytical model is presented for predicting complete shear load-deformation response of reinforced or prestressed concrete sections taking into account the concrete confinement. This model is based on the equilibrium, compatibility equations and stress-strain relationships which are formulated in term of average stresses and average strains. Ac...

This work is a part of industrial waste development program. It is devoted to the study of recyclability, as reinforcement for concrete, of chips resulting from the machining of steel parts. We're interested in this study to the rheological behavior of chips reinforced fresh concrete and its mechanical behavior at a young age. The evaluation of the...

The flexural behavior of reinforced concrete beams is a well-known problem. In the classical studies about this subject, shear strength is neglected or taken into account by simple formula from the linear theory of elasticity, neglecting flexure and shear interaction. For this reason, these classical methods allow to predict only the flexural fract...

This work is a part of an industrial waste development program. It is devoted to the study of recyclability of chips resulting from the machining of steel parts as reinforcement for concrete. We are particularly interested in this study in the rheological behavior of chips reinforced fresh concrete and its mechanical behavior at young age. The eval...

The addition of a high percentage of silicon and a small percentage of magnesium to aluminum are the main enhancers largely used to improve the mechanical characteristics. Our goal, here, is to make a direct contribution to the mechanical properties in traction, the hardness, the resilience and the structural properties of the AlSi13 alloy used in...

In this experimental study, we are interested in local fiber wavy chips derived from waste machining steel parts. This work has focused on studying the mechanical behavior of reinforced concrete in tension of this type of fiber. Direct tensile tests were carried out on samples in free weights section and square (100x100) mm 2 . This test involves t...

Mechanical behavior of steel fiber reinforced concrete has been studied by the direct tensile test. This fiber concrete is obtained by adding machining chips to the bare concrete. Six fiber contents were adopted (W=0.4%, 0.6%, 0.8%, 1%, 1.2% and 1.5%) for two sand over gravel ratio (S/G = 0.8 and S/G = 1). The results obtained showed that the fiber...

Matériaux & Techniques 99, 327–338 (2011) c EDP Sciences, 2011 DOI: 10.1051/mattech/2011106 www.mattech-journal.org Caractérisation en traction directe du béton de fibres métalliques S. Djebali1, D. Atlaoui2 et Y. Bouafia2 1 Laboratoire de Mécanique, Structures et Énergétique (LMSE), Université Mouloud Mammeri de Tizi-Ouzou, BP17RP, Tizi-Ouzou...

The modeling of the behavior in pulling of the reinforced concrete of waved fibers (to variable geometry), is based on the study of the behavior of the fiber in the concrete matrix. Writing the energy equilibrium of an undulating fiber at the time of the sliding, the movement is governed by a differential equation. The pull-off strength of the fibe...

The contribution of the cracked stretched concrete is taken into account in the calculations of structures to estimate accurately the deformations and also to limit, for the sake of security, the opening of cracks. The aim of this study is to lay down the expressions which are necessary to perform these calculations, the basic element of which is t...

The contribution of the cracked stretched concrete is taken into account in the calculations of structures to estimate accurately the deformations and also to limit, for the sake of security, the opening of cracks. The aim of this study is to lay down the expressions which are necessary to perform these calculations, the basic element of which is t...

An analytical model is presented for predicting complete shear load-deformation response of reinforced or prestressed concrete beams. Equilibrium, compatibility and stress-strain relationships are formulated in term of average stresses and average strains. according to the assumption of smeared cracks. This model is able to analyze sections having...

RÉSUMÉ. Depuis 1999, des nouvelles Règles Parasismiques Algériennes (RPA 99) ont été établies sur le modèle Américain. Elles proposent une nouvelle classification des catégories de site. Quatre catégories de site associées à quatre spectres de réponse de calcul sont alors proposées. Dans ce travail, nous montrons que dans la gamme des hautes fréque...