Ecology, Environment and Conservation Paper

INFLUENCE OF UREOLYTIC BACTERIA IN IMPROVING PERFORMANCE CHARACTERISTICS OF CONCRETE

Prabhath Ranjan Kumar Soda, Poornima V., Vighnesh Rameshkumar and R. Venkatasubramani

Abstract

A distinctive strength and durability associated phenomenon in numerous concrete structures are subtle cracks and pores in the concrete. Principally, related cracks and pores result in increasing permeability of cement concrete matrix. Entry of water, atmospheric pollutants and their byproducts can deteriorate the matrix and diminish the strength and durability apparently. Also, it causes corrosion of the installed reinforcement which in turn, enhances the maintenance cost. Previous research works have dealt with conventional repair methods like epoxy injection, latex treatment and provision of further steel in design to limit the crack width within permissible limit. On the other hand, bioconcrete is reliable in enhancing the strength, durability and healing of cracks. In this research the bacterial strain, Bacillus licheniformis MTCC 3606, derived from soil is used for calcite precipitation and for achieving better strength and durability properties in hardened concrete. Also, the bacteria were checked for compatibility with different type of superplasticizers. It is inferred from the test results that the compressive and flexural strength got increased significantly. It increased the resistance to acid attack and water absorption in concrete appreciably. SEM analysis has shown the calcite precipitation inside the bacterial concrete. The results obtained from SEM analysis were confirmed by XRD.