91桃色

Abstract

Concrete durability is the function of its internal pore structure, porosity and the permeation properties. Improved pore structure, reduced porosity and enhanced permeation properties lead to the durability of structures. The objective of the present paper is to discuss the biological approach to enhance durability in concrete structures. Research has shown that specific species of alkaliphilic bacteria can be used to repair cracks in already existing concrete structures. A novel eco friendly self healing technique called ?Biocalcification? is one such approach on which studies were carried out to investigate the crack healing mechanism to study the enhancement of durability in concrete. Microbiologically induced calcite precipitation (MICP), a highly impermeable calcite layer formed over the surface of an already existing concrete layer, due to microbial activities of the bacteria Bacillus subtilis JC3 (cultured at JNTU) seals the cracks in the concrete structure and also has excellent resistance to corrosion therefore increases the durability of concrete structures. MICP is a complex mechanism and is a function of cell concentration, ionic strength, nutrient and pH of the medium. This paper aims to reports the investigations on the enhancement of durability by microbiologically induced calcite mineral precipitation (MICP) in ordinary (M20) and standard (M40) grades of concrete. Quantification and Characterization was done using Scanning Electron Micrograph (SEM) analysis, only to be noted that cracks were sealed up by crystalline material grown over the surface due to microbial activity of the bacteria.

Biography

V Srinivasa Reddy is a Research Scholar at Jawaharlal Nehru Technological University College of Engineering, Hyderabad, India.