Properties of natural reinforced earth-bases composites: advantages and drawbacks with synthetic reinforcemen

Abstract

The increase of awareness of the need to improve the sustainability of the construction industry and the concurrent development of "Green Technologies" has led to the raise of bio-composite materials with natural reinforcements for building applications. This process has involved the revival of the interest in the use of natural reinforced earth materials. Of these, the earthy materials with natural or synthetic reinforcements belong to a field that hasn’t been very much developed beyond traditional or emergency applications in architecture. The most determining aspect to develop products and systems based on reinforced earth based composites is the huge diversity on its physical and mechanical properties. Composites properties depend on diverse variables, among which are those concerning the type of soil and ground grain, type of reinforcement fibers (natural or synthetic), natural conditions in which were obtained, processing methods and characteristics of the possible matrices used as stabilizers. This paper aims for a comprehensive review of literature of the available natural or synthetic reinforced earth based composites. General characteristics of the mainly used reinforcement agents depending on its origin, type, composition, structure, chemical composition and mechanical properties of the studied material (animal hair, jute, sisal, coir, flax, hemp, pineapple fiber, bamboo, rice husk, oil palm, etc). Moreover, different processing methods to improve physical and chemical characteristics, together with processing systems and factors affecting the production and characteristics of these composites will be considered (moisture content, type of reinforcement, ratios, distribution, coupling agent, etc.). The present review is intended to update the overview the research of these kind products as well as to outline the main objectives and issues addressed in these current lines of research.