Study of Compressed Earth Blocks as an Alternative Wall Building Material

Abstract

—This research reports on the investigation into the strength and durability in-terms of shrinkage of compressed earth blocks produced from natural site soil and modified or reconditioned soil types. The soils were stabilized chemically by cement and lime stabilizers with a mix proportion of 5 and 7% cement as well as 10 and 15% lime, the control treatment being with no stabilizer (un-stabilized) in both soil types. Hence, for each soil type five different treatments were considered for the study. Four blocks were produced for each treatment. The engineering characteristics and classification of soil samples were determined by applying suitable tests. Furthermore, the compressive strength, dry block density and dimensional stability in-terms shrinkage (volume change) of the sample earth blocks were investigated after the elapse of their respective curing periods. In general, significant improvements in dry compressive strength and dimensional stability characteristics were exhibited by the stabilized and compressed earth blocks. With regard to dry compressive strength of blocks, the result showed that the average compressive strength of cement stabilized blocks were found to be 1.42 and 1.53MPa in case of natural site soil and 2.73 and 2.90MPa in case of the modified soil with a mix proportion of 5 and 7% of cement by weight respectively. Similarly, the average compressive strength of lime stabilized blocks were found to be 1.45 and 2.20MPa in case of natural site soil and 1.38 and 1.45MPa in case of modified soil with a mix proportion of 10 and 15% of lime by weight respectively. Accordingly, by considering a minimum dry compressive strength of 2MPa as an acceptable strength, the 15% lime stabilized earth blocks in the case of natural site soil as well as the 5 and 7% cement stabilized compressed earth blocks in the case of modified soil have shown a dry compressive strength value greater than 2MPa and hence can be conveniently used as an alternative durable and affordable wall building elements in Jimma area.