Shrinkage of natural plaster materials for straw bale buildings affected by reinforcement fibers and drying

Abstract

This study was carried out to determine the shrinkage percentage of natural plaster materials consisted of soil, sand and different fibers.  Straw was used as a reinforcement fiber for plaster and three types of fibers.  The plaster materials were put under drying temperatures of 30℃, 50℃ and 70℃.  The results revealed that the highest shrinkage was for plaster reinforced by wood shavings fibers, while the lowest shrinkage was for plaster reinforced by barley straw fibers for treatments A, B and C.  Also, the plaster without reinforcement fibers had a lot of cracks and problems that destroyed plaster.  The reinforcement fiber had a greater effect on the drying shrinkage than sand.  The study indicates that drying the plaster at 30℃ with a lot of straw can decrease the shrinkage and cracks.

Keywords: shrinkage percentage, drying temperature, earth plaster, sand, straw, straw bale buildings

Citation: Ashour, T., and A. Derbala.  Shrinkage of natural plaster materials for straw bale buildings affected by reinforcement fibers and drying.  Agric Eng Int: CIGR Journal, 2010, 12(1): 55-62.