Screening a suitable coating for expanded clay aggregate as bacteria carrier for manufacturing self-healing concrete

Porous aggregate is a promising bacterial carrier in manufacturing bacteria-based self-healing concrete as it can retain a high amount of bacteria in its pores. However, as the pores of LWA are more open pores, the leakage of bacteria is a big problem that needs to be solved after the encapsulation process. Thus in this research, expanded clay LWA was treated in order to improve the encapsulation efficiency of Bacillus sphaericus (BS) for manufacturing self-healing concrete. Several coatings such as Polyvinyl Alcohol (PVA), Sodium Silicate, and Sodium Alginate were applied as surface protection on LWA by means of dipping. The ureolytic activity, pH evolution, and the leakage of bacteria from coated LWA were examined and compared to the non-coated LWA samples. The result showed that sodium alginate is suitable for LWA coating. It did not kill the bacteria, indicated by the detection of ureolytic activity in the crushed LWA sample coated with sodium alginate. In addition, sodium alginate coating on the LWA was also proven to decrease the leakage of bacterial cells from the pores of LWA.

ISBN:9781399908320

Publication year:2021

Accessibility:Closed