R. Boissiere

• Doctor of Engineering
• Professor (Assistant) at University of Lorraine

In todays world, the environment and the economy, are becoming more and more important, especially in the field of construction. As a result, many researches are beginning to emerge in order to find alternatives to the usual reinforced concrete. In this article, research is focused on constructions using local materials, more specifically on lateri...

Monitoring the health of civil engineering structures using implanted deformation, temperature and corrosion sensors would further improve maintenance and extend the service life of those structures. However, sensor integration poses a number of problems, due to the presence of cables and on-board electronics. Passive, wireless SAW sensors offer a...

Monitoring the health of civil engineering structures using implanted deformation, temperature and corrosion sensors would further improve maintenance and extend the service life of those structures. However, sensor integration poses a number of problems, due to the presence of cables and on-board electronics. Passive, wireless SAW sensors offer a...

The application of timber-concrete composite (TTC) connections in structures has increased over the past decades. The mechanical behaviour of these connections is largely influenced by the stiffness of the joints, deformations and strength. This paper presents an analytical calculation of stiffness, short-term laboratory experiments and numerical s...

The fundamental properties of recycled aggregate (RA) and RA concrete have been the subject of extensive research over the past few decades, leading many countries to issue regulations or proposals regarding their use. In each case, full or partial replacement of natural aggregates (NA) with recycled alternatives has proven to be a practical option...

This paper presents a mixed design trial of structural concretes with laterites from Benin. These materials are often the only granular resources readily available in many tropical regions. In the first step concretes were designed with raw laterites, but the performances obtained were rather disappointing in spite of high cement dosages. A detaile...

This work enrolls in the context of eco materials. It concerns the field of transformation of local shrub forest resources and lateritic earth with low market values into building materials and is developing a process for the valorization of lateritic nodules, Borassus aethiopum (palmyra) and Calamus deerratus (rattan) in the engineering of modern...

This work enrolls in the context of eco materials. It concerns the field of transformation of local shrub forest resources and lateritic earth with low market values into building materials and is developing a process for the valorization of lateritic nodules, Borassus aethiopum (palmyra) and Calamus deerratus (rattan) in the engineering of modern...

The current study is part of a larger project called RECYBETON developed in France since 2012. This part of project deals with the important properties of hardened concrete of RA, from microstructure to properties related to durability and fire behavior. The founding objective of the RECYBETON Project is generally not to formulate concrete with a g...

The European design code for steel structures, Eurocode 3 Part 1-1, defines the buckling resistance criterion, which enables initial imperfections to be taken into account without including them in the model structure. The initial imperfections are taken into account by the reduction factor for buckling χ. This reduction factor depends on the imper...

The study of the properties of Recycled Aggregates (RA) and the basic properties of RA concrete has been on going over the last few decades, leading a number of countries to establish standards or recommendations supporting their use. In all the cases, the full and partial replacement of the Natural Aggregates (NA) with recycled alternatives has be...

The application of timber-concrete composites (TCC) connections in structures has increased over the past decades. The mechanical behaviour of these connections is largely influenced by the stiffness of the joints, both with regard to deformations and strength. This paper presents laboratory experiments and numerical simulations using ABAQUS perfor...

The study of the properties of Recycled Aggregates (RA) and the basic properties of RA concrete has been on going over the last few decades, leading a number of countries to establish standards or recommendations supporting their use. In all the cases, the full and partial replacement of the Natural Aggregates (NA) with recycled alternatives has be...

This paper presents an experimental program carried out to study the global flexural performance of reinforced concrete beams strengthened internally with Carbon Fiber Reinforced Polymer rods (CFRP) by using Side Near Surface Mounted (SNSM) technique. The CFRP rods were placed laterally adjacent to the longitudinal steel bars inside precut grooves....

Stresses of a structure are determined with a first or a second order analysis. The choice of the method is guided by the potential influence of the structure’s deformation. In general, considering their low rigidity with regard to those of buildings, scaffolding and shoring structures quickly reach buckling failure. Imperfections, such as structur...

The present study deals with the mechanical behavior of reinforced concrete columns made from Recycled Coarse and Fine Aggregates replacing the natural ones. These columns are loaded in eccentric static compression with different replacement ratio in their mix, with the same compression strength class. An experimental program followed by an analyti...

This study deals with the effect of initial imperfections on the bearing capacity of buckling for slender elements. By adopting two forms of initial deformed shapes and by using the deformation energy method, the critical load formulae were derived. Buckling tests by creating initial defects and respecting the theoretical boundary conditions showed...

The effects of punch geometry and sample size on forming limit diagrams in expansion are investigated in the case of a 2024 aluminium alloy. Four configurations were selected: flat punch (Marciniak test) or hemispheric punch and decimetric vs. centimetric tooling dimensions. Both decimetric and centimetric deep-drawing devices are associated with a...

Lightening structure is one of the goals of many fields of research. As a result, magnesium alloys are studied due to their low density. However, one drawback of these alloys is their low formability at room temperature due to their hexagonal closed-packed structure. In the present work, the forming capacity of an AZ31 Mg alloys has been studied us...

The effects of punch geometry and sample size on forming limit diagrams in expansion are investigated in the case of a 2024 aluminium alloy. Four configurations were selected: flat punch (Marciniak test) or hemispheric punch and decimetric vs. centimetric tooling dimensions. Both decimetric and centimetric deep-drawing devices are associated with a...

The deformability of wrought magnesium alloys at room temperature is limited and a way to overcome this limit is to carry out forming operations in warm or hot conditions. In the case of fine grained alloys, superplastic properties can be generally achieved but in this regime, the Mg alloys are sensitive to strain induced cavitation. However, large...

In order to extend the industrial use of SuperPlastic Forming (SPF), efforts have been devoted in the recent past to reduce forming times. The more spectacular result is probably the development of the so-called Quick Plastic Forming (QPF) technology which has been particularly investigated in the US automotive industry. QPF has been mainly studied...

Except if strain induces damage, the plastic stability can be roughly estimated thanks to the value of the strain rate sensitivity parameter m. In conventional magnesium alloys, moderate values of m (typically close to 0.3) can be frequently obtained during high temperature deformation. Such values allow reaching significant elongations to fracture...

Superplastic forming (SPF) of metallic alloys allows the production of components with particularly complex shapes since in this regime, due to the predominance of grain boundary sliding (GBS), the material exhibits a high plastic stability. However, in many light alloys (i.e., Al or Mg alloys), superplastic deformation induces damage leading to pr...

Extending recent numerical studies on two-dimensional amorphous bodies, we characterize the approach of the elastic continuum limit in three-dimensional (weakly polydisperse) Lennard-Jones systems. While performing a systematic finite-size analysis (for two different quench protocols), we investigate the nonaffine displacement field under external...