Fibre-reinforced Soil Based Construction Materials

Abstract

Soil based construction materials (SBCMs) are formed of a mixture of gravel, sand and clay which, when mixed with water, may be used for construction. They can be an environmentally-friendly alternative to more traditional construction materials such as concrete and fired brick. SBCMs commonly incorporate foreign material into the soil to enhance the material properties. Many guides on SBCM construction advocate the use of cement as a stabiliser to strengthen the material, which detracts from the environmental credentials that earthen construction materials possess. Alternatives methods to strengthen SBCMs are therefore needed.

In this thesis, waste wool fibres from a carpet manufacture are investigated as a potential alternative fibrous reinforcement in rammed earth (RE), and its effect on the behaviour of stabilised and unstabilised RE is assessed. Compressive tests, shear tests and splitting tests are performed to study the effect of fibrous (wool) and chemical (cement) stabilisation on RE, and recommendations on further use of these materials are made. Tests are also performed to investigate the shrinkage of different clays (bentonite and kaolinite) used in RE when mixed with sand or wool, in order to determine the effects of these materials on shrinkage behaviour.
Finally, advice is provided regarding the use of fibrous reinforcement in SBCMs, which is applicable to both the SBCM industry and research, and new and pre-existing research areas are identified to prompt further study.