Investigation into the shear behaviour of rammed earth using shear box tests.

Scientific investigations into the structural properties of rammed earth (RE) are gaining momentum and a number of parameters (e.g. suction, particle size distribution and water content), influential on material strength and other properties, have been identified and investigated. Cement stabilisation is undergoing continued investigation, while fibrous stabilisation, also known as fibre reinforcement, is beginning to gain attention. Recent experiments have shown that the addition of fibres such as straw or wool to RE or other earthen materials can improve its flexural strength. Less attention, however, has been paid to the fracture behaviour of RE, and to its shearing behaviour. This paper presents a preliminary investigation into the shearing behaviour of stabilised and unstabilised RE reinforced with waste natural fibres. The Direct Shear Test (DST) is used to obtain peak shear stresses and displacements, from which strength parameters (φ’) and cohesion (c’) are obtained. This paper also presents some scanning electron microscope (SEM) images of these materials. The results show that wool fibres decrease the density and peak shear strength of RE. The effect of water, wool and cement content on φ’ and c’ are also discussed

ASTERIX and 2.0 Knowledge Management : exploring the appropriation of 2.0 KMS via the Myth of the Gaulish village

International audienceKnowledge Management Systems (KMS) in companies have profoundly changed in recent years. They have become KMS 2.0 that aim to transform the firm and are driven by a new relationship to knowledge in line with 2.0 organisations. These 2.0 KMS have implemented modes of organisation that disrupt those that previously guided firms’ performance. This can sometimes lead to paradoxical organizational dysfunctions as witnessed by the difficulties faced by some traditionally hierarchical French companies. Through a case study of Constructor and a theoretical background on IS appropriation in organizations and myths in management, we show how the Asterix myth contributes to understanding how 2.0. KMS are appropriated in such companies. We find evidence of similarities regarding knowledge and Knowledge Management between the Asterix’ myth and the behaviours and practices concerning knowledge management within Constructor. As a result, the Asterix’ myth may be a relevant perspective for understanding the obstacles, advantages and appropriations of 2.0. KMS within French organizations

A. C. Pickett Mexican War journal

This collection contains a personal journal kept by Alexander Corbin Pickett during his service in the Mexican-American War

Investigation into the shear behaviour of rammed earth using shear box tests

Scientific investigations into the structural properties of rammed earth (RE) are gaining momentum and a number of parameters (e.g. suction, particle size distribution and water content), influential on material strength and other properties, have been identified and investigated. Cement stabilisation is undergoing continued investigation, while fibrous stabilisation, also known as fibre reinforcement, is beginning to gain attention. Recent experiments have shown that the addition of fibres such as straw or wool to RE or other earthen materials can improve its flexural strength. Less attention, however, has been paid to the fracture behaviour of RE, and to its shearing behaviour. This paper presents a preliminary investigation into the shearing behaviour of stabilised and unstabilised RE reinforced with waste natural fibres. The Direct Shear Test (DST) is used to obtain peak shear stresses and displacements, from which strength parameters (φ’) and cohesion (c’) are obtained. This paper also presents some scanning electron microscope (SEM) images of these materials. The results show that wool fibres decrease the density and peak shear strength of RE. The effect of water, wool and cement content on φ’ and c’ are also discussed

Geotechnical aspects of earthen construction materials

ABSTRACT: Earthen construction and soil-based construction materials (SBCMs) are expanding areas of interest worldwide. They offer the potential for low carbon and embodied energy, sustainability through recycling and an alternative to high energy materials such as fired masonry. The materials that are generally used in earthen construction can be identified as manufactured unsaturated soils. Until recently, however, these materials have rarely been studied using a geotechnical approach, and there is a general lack of recognition of the key mechanisms at work mechanically and hydraulically. In this paper we review geotechnical aspects of soil-based construction materials examining the effects of suction and environmental conditions, and demonstrating behaviour in shear, compression and fracture. We cover materials which are both unstabilised, where the primary source of strength is suction, and materials which are stabilised with cement, lime or fibres. The review is backed up by experimental results from laboratory and field testing undertaken over a number of years at Durham and UWA. RÉSUMÉ: Construction en terre (en utilisant "des matériaux de construction à base de sol - ») est une extension du domaine de l'intérêt dans le monde entier en raison de faibles émissions de carbone potentiel et l'énergie intrinsèque , et la durabilité à travers le recyclage , et il est possible d' utiliser beaucoup plus pour remplacer les matériaux de haute énergie tels que la maçonnerie tiré . Les matériaux qui sont généralement utilisés dans la construction en terre peuvent être identifiés comme les sols non saturés fabriqués . Jusqu'à récemment, toutefois , ces matériaux ont rarement été étudié en utilisant une approche géotechnique , et il ya un manque général de reconnaissance des principaux mécanismes à l'oeuvre mécaniquement et hydrauliquement . Dans cet article, nous examinons les aspects géotechniques des matériaux de construction à base de sol - examinant les effets de la succion et des conditions environnementales , et le comportement en cisaillement démontrer , la compression et de fracture. Nous traitons des matériaux qui sont à la fois stabilisées , où la première source de force d'aspiration est , et les matériaux qui sont stabilisés avec du ciment , de la chaux ou de fibres . La revue est soutenue par expérimentales ré- sultats de tests en laboratoire et sur le terrain entrepris depuis un certain nombre d'années à Durham et l'UWA