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The paper presents a novel experimental investigation, comprising tests on cement-stabilised rammed-earth (CSRE) prisms and columns of varying slenderness ratios, focusing on the effects of concentric axial loading and variation of the moisture content along the height of the column, and of the slenderness ratio on capacity/stress reduction factors. An attempt was also made to determine the ultimate compressive strength ( σu) of columns using tangent modulus theory and the validity of using masonry design rules for the design of CSRE columns. The results showed that the load-carrying capacity of columns decreased with increasing slenderness ratio. The location/zone in the column where the difference in the moisture content was relatively higher (i.e. 3·86% and above) at the time of testing was found to be the weakest zone leading to untimely failure. Tangent modulus theory underestimated σu. The experimental reduction factors were found to be more conservative than the masonry code provisions. The characteristic strength obtained for CSRE columns yielded a relatively higher safety factor and showed that it is possible to construct a single-storey load-bearing house when designed properly. [ABSTRACT FROM AUTHOR]

The following research has been undertaken in collaboration with 'Engineers Without Borders', with the aim of investigating procedures and materials to reduce the cost of housing construction for local indigenous communities on the Dampier Peninsula, a remote area in the north of Western Australia. This paper shows the criteria and the logic that lead to identifying cement-stabilised rammed earth as a viable alternative to the standard typologies (mainly steel-framed houses) in remote areas of Australia. To overcome the limits generated by the lack of proper Australian standards recommendations in rammed-earth construction, the suitability of the soil available in situ has been experimentally investigated. The unconfined compressive strength for different soils and different cement contents has been studied. In addition, the accelerated erosion test has been carried out. Even though the soil collected in situ has been shown to be a suitable construction material, the competitiveness and wide-ranging benefits of rammed earth are undermined by the lack of more comprehensive studies on this alternative building technique. [ABSTRACT FROM AUTHOR]

Rammed earth is a manufactured material comprising sand, gravel and clay, which is compacted between forms to build walls. Primarily a historic method of construction, it is now receiving considerable interest worldwide owing to its zero reliance on materials such as cement, and its potential for recycling. Despite its longevity, the source of its shear strength is poorly understood. This paper presents initial laboratory test results that point to the main source of strength in rammed earth being suction, and indicating that recent advances in unsaturated soil mechanics may also be applied to this material. [ABSTRACT FROM AUTHOR]