Environmental Water Related Deterioration of Compressed Stabilized Earth Block Structures in Uganda

Abstract

The provision of shelter for all has not yet been realised. The main challenge is the high cost of building materials. Compressed and stabilised earth blocks (CSEB) are now recognised as low cost materials. While their green properties are well understood, the durability of these materials remain enigmatic. The objective of this research was to investigate the durability of CSEBs as used in the humid tropics. The interplay between the block and the effects of natural exposure conditions, especially the dynamics of rainfall, are examined. Through a methodology involving literature reviews, physical inspections, and exposure condition survey, block behaviour and defects over time are rigorously investigated. Water deterioration modes and their mechanisms of progression are discussed. The sources of water, agents, actions, effects, affected properties, and rate of deterioration are described. Defects were exhibited mainly as surface erosion, and cracking. However, it is still possible to improve the durability and wear resistance of CSEBs for use in the humid tropics. The improvement is achieved via lowered water absorption, and improved design codes, tests and standards. The findings are likely to contribute to the future widespread use of CSEBs. The findings raise a number of questions for further studies.

Keywords: Compressed Earth Blocks, Deterioration, Durability, Rainfall, Soil-Cement, Stabilization, Water