Cement-stabilised rammed-earth square column in compression

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 (σ_u) 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 σ_u. 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.