Developing bio-cement using agricultural sources to reduce CO2 emissions in civil construction

Abstract

This study employed the Enzyme Induced Carbonate Precipitation (EICP) to produce bio-cement. Enzyme Urease (low cost, eco-friendly) was extracted from soybean seeds, which obtained high urease activity in the production of bio-cements. The urease activity was also investigated with the change in pH parameters and electrical conductivity in the solution due to hydrolysis of urea (CO(NH₂)₂). The research work used the percolation treatment to solidify the sandy soil at the particle contacts, thus enhancing the strength of sand with the maximum and minimum values ​​corresponding to the compressive strength are 1004,2 kPa and 359,9 kPa, respectively. In addition, CaCO₃ precipitation significantly reduced void volume of soil mass as well as permeability with an initial permeability of 10^-1 cm/s. The carbonate precipitation was also confirmed by microscopic analyzes using methods of X-Ray Diffraction and Scanning Electron Microscope. In addition, the paper also presents an assessment of cost and environmental benefits of reducing CO₂ emissions compared with conventional cement (Portland).