Developing biotechnological technique for reuse of wastewater and steel slag in bio-concrete

• Published in: Journal of cleaner production 2019-08, Vol.229, p.193-202
• Main Authors: Saxena, Shekhar, Tembhurkar, Ajay R.
• Format: Article
• Language: English
• Subjects: Bio-concrete; Compressive strength; Durability; Recycling; Steel slag; Treated wastewater
• ISSN: 0959-6526; 1879-1786
• DOI: 10.1016/j.jclepro.2019.04.363

Rapid growth in urbanization is demanding a huge quantity of natural materials and fresh water for construction activities. Hence in recent years, research is focused towards promoting the use of recycled waste materials and wastewater to fulfill the increasing resource demand and save natural fresh water. Earlier attempts on using waste materials and wastewater reveal the presence of pores and cracks which result in the loss of properties of concrete. To overcome these problems, the present study envisages to provide a solution by developing a bio-concrete utilizing steel slag and wastewater in place of natural aggregate and tap water. For this purpose endospore-forming and urease producing bacteria are incorporated in concrete. The addition of bacteria is responsible for the precipitation of calcium carbonate in concrete matrix which fills the pores of concrete and ultimately increases the strength and durability of concrete. The present research reveals that the loss in properties of concrete due to use of wastewater is compensated by microbiologically induced calcium carbonate precipitation phenomena of bio-concrete. Water absorption of bio-concrete is found to be reduced by 15.5% and increment in compressive and flexural strength is found as 33.1% and 12.5% respectively as compared to control concrete. This is also supported by the other advanced tests such as ultrasonic pulse velocity, rapid chloride permeability, scanning electron microscopy and X-Ray diffraction tests that the concrete attains dense and compact microstructure with increase in the durability. •Bacillus cereus bacteria can be used for the enhancement of strength and durability of concrete.•Reuse of wastewater in concrete conserves the fresh water.•Steel slag can be reused for partial replacement of natural coarse aggregate.•Advance analysis was done for the hardened properties of bio-concrete.