Cement Mortar Reinforced with Natural Fibers

Abstract

The relatively high cost of man-made fibers and wire meshes used in fiber reinforced concrete and ferrocement, combined with a reduction in the usage of asbestos fibers, make it necessary to evaluate natural fibers as possible substitutes. This is particularly true in some low-cost housing applications, such as those used in Mexico, where the cost of the reinforcement represents a major portion of the total cost. Some natural fibers of the agave family, which are widely available in Mexico, show surprisingly high mechanical properties; yet little effort has been devoted so far to using them efficiently. This paper describes the results of a cooperative research project to study the use of natural agave fibers as possible reinforcement for portland cement-based matrixes. The following questions are answered: I) What are the essential mechanical properties of these fibers? 2) What are the difficulties encountered in mixing them with a mortar matrix? 3) What are the optimum and practical maximum amounts of fibers that can be mixed? 4) Can a composite showing an elasto-plastic behavior (or better) under loading accompanied by multiple cracking be obtained? 5) Does the composite have a fairly good durability under various environmental exposures? The results so far are very encouraging and necessitate further systematic research in the use of natural fibers.