Modification of recycled concrete aggregate by calcium carbonate biodeposition

Construction and Building Materials, Volume 34, September 2012, Pages 145-150
Anna M. Grabiec, Justyna Klama, Daniel Zawal, Daria Krupa

Department of Theory of Structures and Agricultural Building Engineering, Faculty of Land Reclamation and Environmental Engineering, University of Life Sciences, Poznan, Poland

Department of General and Environmental Microbiology, Faculty of Agronomy and Bioengineering, University of Life Sciences, Poznan, Poland

Abstract

A growing demand for raw materials leads to danger of premature depletion of the natural sources. An alternative is to use by-products, provided their quality is improved. The paper presents surface modification of recycledaggregateconcrete using biodeposition involving a method employing Sporosarcina pasteurii (Bacillus pasteurii) bacteria. It was possible to obtain reduction in water absorption of aggregate, the effect was more visible in case of finer fractions and for aggregates originating from inferior quality concrete. Calcium chloride was used for precipitation of calciumcarbonate, while culture medium consisting of beef extract, peptone and urea was used for cultivation of microorganisms. In addition, whey, ecologically dangerous by-product from dairy industry was found to be effective as a culture medium. Presence of calciumcarbonate crystals covering aggregate grains was confirmed by observations under scanning electron microscope. In the perspective, the proposed method, upon appropriate improvements, seems worthwhile due to ecological and technological reasons.

Go To Journal

 

Check Also

Flexural Buckling Behavior of WAAM-Fabricated Tubular Columns: An Experimental Analysis - Advances in Engineering

Flexural Buckling Behavior of WAAM-Fabricated Tubular Columns: An Experimental Analysis