An Experimental Study on Strength and Self-Healing Characteristics of Bacterial Concrete

Muzzamil Nisar , Er. Brahamjeet Singh

In modern era, concrete is widely used in building materials. Concrete is durable, strong, and locally available. It has a property of resisting the compressive load to a limit but if the load applied goes beyond the limit, the strength of concrete is reduced because of the development of the cracks in the concrete. Thus the treatment for these cracks becomes very expensive.  The development of cracks in concrete affects the serviceability limit of concrete.  The influx of water and harmful chemicals into the concrete may decrease both the strength and life.  Structural failure may be caused by micro-cracks.  One way to avoid costly manual maintenance and repair is to include an  autonomies self-healing mechanism  in  concrete.   One such an alternative mechanism is correctly being studied i.e.  a  novel  technique  based  on  the  application  of  bio-mineralization of  bacteria  in  concrete.  The  applicability  of  specifically  calcite  mineral  precipitating  bacteria    for  concrete  repair  and  plugging  of pores  and  cracks  in  concrete  has  been  investigated  and  studies  on  the  possibility  of  using  specific  bacteria  as  a  sustainable  and  concrete  embedded  self-healing  agent  was  studied  and  results  from  ongoing  studies  are   discussed.  Synthetic polymers such as epoxy treatment etc.  are  now  a  days  used  for  repair  of  concrete  are  harmful  to  the  environment,  hence  the  biological  repair  technique  is  focused.   Recently,  it  has  been  found  that  microbial carbonate  Precipitation  resulting from the  metabolic  activities  of  micro-organisms  in  concrete modified  the  overall  behavior  of  concrete.  Hence,  in this paper, we explain the  bacterial  concrete,  its  classification  and types  of  bacteria,  chemical  processes  to  fix  the  micro cracks, advantages ,disadvantages  and the possibilities on application of micro-organisms in the concrete.  The different strengths of normal concrete and concrete with bacillus were analyzed and the tests were conducted and compared.