The Application And Quality Management Of New Building Materials

The concept of microbial concrete is barely exercised in the country as it is also relatively new in the more advanced parts of world.Multiple researches all over the globe are being carried out in the wake of promising results found on the improvement of cementation mix performances due to the application of live microorganisms.This research,entitled"Investigation on the Potential Improvement of Mechanical Strength of Portland Cement Mixes by Application of Bacteria" has tried to show the effect of introducing Sporosarcina pasteurii into concrete as well as mortar with a particular focus on the compressive strength.Different set of experiments were carried out on:analysis of the effect of the bacterial medium while varying water-to-cement ratios on concrete,the effect of different bacterial concentration in both concrete and mortar as well as the effect of the bacterial medium.The experiments tried to show the effect of introducing these components on early and late strength of concrete with 7th,14th,28th and 56th day tests scheduled to proceed.With the results found until the preparation of this paper,it was found out that the bacterial medium had little effect on both the concrete and the mortar,while the bacterial nutrient,whose main constituent is yeast extract,significantly reduced the compressive strength in both mortar and concrete.Additionally,the samples with the aforementioned bacteria introduced into the mix recovered some part of their lost strength(and in some cases,more strength than what was lost).This research was done by indirectly trying to prove that this gain of strength was due to the calcite precipitation induced by the bacteria,as it only relied on the results of the compressive strength tests.The paper concludes by stating the need of further investigation,especially with regards to finding a better substitute for yeast extract of the bacterial nutrient so that with only calcite precipitation,one will be able to achieve a higher strength in concrete and mortar.