Engineering Characteristics Of Compressed Earth Blocks Stabilized With Lime And Coconut Husk Ash

Abstract

The cost of renting or owning a property in Ghana has risen considerably as a result of the country's growing population and increasing demand for housing. Expensive building materials is one of the causes of this situation. There is therefore the need to use locally available building materials to come up with innovative ways to provide sustainable housing for the citizens especially the low-income group. This research aims at investigating the engineering characteristics of compressed earth blocks stabilized with lime and coconut husk ash. Laterite blocks of size 300mm x125mm x 200mm were prepared using the following mix ratios: 0%, 5%, 10% lime, and 0%, 2%, 4% coconut husk ash (CHA). The block samples were tested for density, compressive strength, water absorption and abrasion resistance in order to observe their performance after 7, 14, 21 and 28 days of curing. Dry compressive strength increased by 38% - 110% as the amount of lime and CHA was increased in the blocks. Results show that blocks stabilized with 10% lime and 4% CHA recorded the highest compressive strength with a value of 2.53MPa which falls within the required building standards. The stabilized block samples recorded dry density values that were slightly higher than the un-stabilized block samples, as well as a higher resistance to water absorption than the un-stabilized block The durability of the blocks was determined by subjecting the blocks to abrasion resistance test. The stabilized blocks showed higher resistance as compared to the un-stabilized blocks with the blocks stabilized with 10% lime and 4% lime showed the highest resistance to abrasion of 3.0cm/g. The properties of the blocks were therefore improved by the introduction of lime and coconut husk ash. This study will be of great benefit to the construction industry since it provides a low-cost alternative to sandcrete blocks. These blocks are not only durable but also environmentally friendly. The use of coconut husk in compressed earth blocks also helps in solving regional waste disposal problem. This research will also be of benefit to low-income groups since it promotes affordable housing.