• Sciences de l'Homme et Société/Architecture, aménagement de l'espace
  
• Sciences de l'ingénieur
  
• Sciences de l'ingénieur/Matériaux
  
• Sciences de l'ingénieur/Génie civil
  
• Sciences de l'ingénieur/Mécanique
  
• Sciences de l'ingénieur/Génie civil/Matériaux composites et construction
  
• Sciences de l'ingénieur/Mécanique/Matériaux et structures en mécanique
  
• Sciences de l'ingénieur/Mécanique/Mécanique des matériaux
  
• Sciences de l'ingénieur/Génie civil/Génie civil nucléaire
  
• Sciences de l'ingénieur/Génie civil/Risques
  

Afghanistan suffers from four decades of war, caused a massive migration of the rural population to the cities. Kabul was originally designed for 1,5 million people, where now 5 million people live. The importation of modern western styles housing for rapid reconstruction reveals apparent cultural conflict and significant environmental footprint. The new constructive cultures for sustainable reconstruction should necessary consider the use of local materials combined with modern technologies. Earthen architecture underlies the embodiment of Afghanistan architecture. The aim of this research is to revisit traditional afghan earthen construction with the tools of industrial modernity. Three soils of the Kabul region were first characterized. Then, sun-dried mud brick and compressive earth block, with and without stabilization have been prepared and tested in the laboratory to develop the most suitable earth construction element which is cost effective and easily available compared to the imported modern products.

Recent studies focused on the quality of the interfacial transition zone (ITZ) of ordinary concretes made from recycled aggregates (RA), without however focusing on High Performance Concretes (HPC).This paper aims to formulate HPC from RA that are exclusively derived from concrete, whose composition is controlled. These concretes are made in a ready-mixed concrete plant and then undergo a crushing and riddling process to produce RA. Partially saturated gravels are substituted up to 100% in the HPC composition in order to accentuate internal cure phenomenon. This phenomenon was observed and demonstrated using a scanning electron microscope (SEM) in the low Water/Cement (W/C) paste up to a distance of 150 μm from the RA and compared by image processing, to a reference concrete made from natural aggregates (NA).The comparison of the mechanical performances and the microscopic analysis of HPC show that the characteristics transfer of the RA seem to favor a hydration of the paste by a mechanism of desorption of their absorbed water, in a process of “internal cure”. The internal cure appears optimal for concrete C60. In addition to this observation, there was an increase in the strength of the recycled HPCs compared to control natural-aggregate HPCs.

Dans un premier temps, la nature pétrographique et les propriétés physiques de deux terres à bâtir seront caractérisées (analyse granulométrique, densité spécifique, limite de liquidité et indice de plasticité). Les propriétés physiques de deux briques de terre crue (un adobe et une brique de terre compressée stabilisée à la chaux) fabriquées à partir de ces deux terres seront ensuite mesurées (masse volumique apparente, porosité, conductivité thermique, coefficient d’absorption d’eau, isotherme de sorption, comportement au feu). Les résultats obtenus montrent que les propriétés physiques qui sont le plus influencées par la nature de la terre utilisée sont la rétention d’eau et le comportement au feu.

The development of tools, using a micromechanical approach, predicting the macroscopic behaviour of heterogeneous materials such as concrete, requires the knowledge of their microstructures (geometrical properties of phases), the behaviour of phases and the interaction laws between phases. This study is focused on a numerical modelling of a local shear test on a cement paste-aggregate composite using a cohesive zone model with the objective to identify the behaviour of the cement paste-aggregate interface. The computations use a 3D finite element modelling of the composite, using a cohesive law at the interface between the two phases. The cohesive model mimics the behaviour of the well-known interfacial transition zone. This work presents a methodology for the identification of cohesive law parameters at different stages of hydration and for different confining stresses using experimental results.