Mostafa Samadi

Application of Proteus mirabilis and Proteus vulgaris mixture to design self-healing concrete

AbstractThis study investigated two indigenous micro-organisms that can be isolated from soil. The isolated micro-organisms could precipitate calcium carbonate. These micro-organisms were applied to design self-healing concretes. Concrete is one of the most important materials which is used to build structures. Strength and durability of concrete is very important. Hence, a lot of research in this field is being conducted. Although a few reports can be found on the use of different micro-organism to design self-healing concretes, no research has been carried out to isolate suitable indigenous micro-organisms in Malaysia. In this study two strains of microorganisms were isolated from soil. Broken concrete was treated by a medium culture (MC) containing micro-organisms. Results of this study showed that, cracked concrete could be filled by calcium carbonate after treating by a MC containing micro-organisms. However, this treatment is not very effective on the strength of concrete. Results of this study can ...

Binary Effect of Fly Ash and Palm Oil Fuel Ash on Heat of Hydration Aerated Concrete

The binary effect of pulverized fuel ash (PFA) and palm oil fuel ash (POFA) on heat of hydration of aerated concrete was studied. Three aerated concrete mixes were prepared, namely, concrete containing 100% ordinary Portland cement (control sample or Type I), binary concrete made from 50% POFA (Type II), and ternary concrete containing 30% POFA and 20% PFA (Type III). It is found that the temperature increases due to heat of hydration through all the concrete specimens especially in the control sample. However, the total temperature rises caused by the heat of hydration through both of the new binary and ternary concrete were significantly lower than the control sample. The obtained results reveal that the replacement of Portland cement with binary and ternary materials is beneficial, particularly for mass concrete where thermal cracking due to extreme heat rise is of great concern.