Effect of the addition of coal-ash and cassava peels on the engineering properties of compressed earth blocks

In developing countries, such as Colombia, earth construction is economically the most efficient means to solve housing problem with the least demand of resources. Traditional earth construction techniques such as compressed earth blocks are experiencing a new popularity, taking into account that they constitute green building materials becoming economically competitive. The availability everywhere of soils as raw materials, the low energy consumption and the simplicity of the production process justify their great usage as primary housing material in developing countries. A series of test compressed earth blocks were made using a clay-rich soil, without coal-ash and stabilized with coal-ash, in a Cinva-Ram hydraulic machine. The use of cassava peels as novel organic materials were also introduced in the preparation of the compressed earth blocks. The objective of this study is to investigate the effect of the addition of coal-ash and cassava peels on the engineering properties of compressed earth blocks. The samples were tested for flexion, compression and absorption in order to observe their performance. Results show that the compressive and bending tests reveal that the compressed earth blocks stabilized with coal-ash produced the best results using a dose less than or equal to 5%. However, doses greater than 5% generate more flexible and fragile compressed earth blocks. Adding cassava peels to the clayed soil increases the required water content for extrusion (apparent plasticity). (C) 2012 Elsevier Ltd. All rights reserved.