Abstract/Summary

The aim of this study is to enhance the strength and the durability of adobe bricks by introducing bio-inspired stabilisers. This research was inspired by the high strength and durability of the termite mounds. The study investigates the stabiliser behind such strong natural constructions. The termite builds its mounds by incorporating a glycoprotein from its saliva to cement the sub-soil particles together. Biomimicry has been used as an approach to investigate the potential for the use of the termites’ construction stabiliser in adobe bricks. Three different glycoproteins sourced from the waste of the meat industry were identified as potential stabilisers in adobe bricks. Bovine serum albumin from cows’ blood, mucin from porcine stomach and gelatine from cold-water fish skin were the three stabilisers used in this study. A fourth stabiliser was made up of several chemicals which together aimed to mimic the termites’ saliva glycoprotein. Two soils were used to prepare adobe bricks for testing. The main soil used in this study was sourced from Devon in the UK. The second soil was sourced from Mayo neighbourhood in Khartoum, Sudan and it was only used in key tests. Adobe bricks were made and stabilised with different concentrations of these bio-inspired stabilisers. Controlled unstabilised adobe bricks were used for comparison. The bricks were tested for their unconfined compressive strength and erosion resistance. The main conclusion in this study is that, bovine serum albumin which is a glycoprotein derived from cows’ blood and considered as a by-product of the beef industry, has proved its potential to be used as stabiliser in earth construction. The use of 0.5 by weight percent of bovine serum albumin resulted in 41% and 17% increase in the compressive strength of the Sudanese and the British adobe bricks respectively. In addition, the use of 5 by weight percent of bovine serum albumin resulted in 202% and 97% increase in the compressive strength of the British and Sudanese adobe bricks respectively. Furthermore, the use of 0.1, 0.2 and 0.5 by weight percent of the bovine serum albumin resulted in 30%, 48% and 70% reduction in the erosion rate of the British adobe bricks respectively. The use of 0.5 by weight percent of the bovine serum albumin resulted in 97% reduction in the erosion rate of the Sudanese adobe bricks. The other stabilisers tested did not result in a significant improvement in unconfined compressive strength of the adobe bricks. However, the use of 0.1and 0.2 by weight percent of mucin from porcine stomach resulted in 28% and 55% reduction in the erosion rate of the British adobe bricks respectively.