Flexural Testing of Compressed Earth Blocks Reinforced with Natural Fibers

Sustainable development of the built environment in developing countries is one of the major challenges of the 21st century. The use of local materials in the construction of dwellings is one of the potential ways to support sustainable development in both urban and rural settings. Raw earth is abundantly available in many locations and can serve as building materials in low-rise dwellings.;This study presents an experimental investigation on the use of natural fibers in Compressed Earth Block (CEB) to increase the toughness of the material. Four different types of fibers were considered as reinforcement of CEBs: rice straw, barley straw, bamboo viscose and hand-planed bamboo fibers. Plate specimens made of earthen materials were formed in a steel mold and compressed with a hydraulic mechanism. The plates were then cut into three replicate specimens, and were loaded in three-point bending to evaluate strengthening and toughening effects of each fiber type. In some cases, plate failure was accompanied by fiber pullout, while in others fiber breakage was the predominant mechanism of failure. All fiber types enhanced the toughness of the CEBs, relative to that of unreinforced units. The results indicated that bamboo fiber enhances the structural performance of CEBs more significantly than either type of straw.