Flyash Enriched with Selected Microorganism By Replacing Part of High Strength Concrete
Author Name : Anita, Neetu Rani
ABSTRACT: In construction industry Concrete is a most widely used construction material and cement is the only manufactured material and other ingredients like coarse aggregate, fine aggregate and water are natural resources to manufacture it and CO2 is emitted in to atmosphere while the production of cement . To reduce harmful effect of CO2, in this project fly ash enriched with bacteria is used to replace ordinary Portland cement in M40 concrete. Casting of specimen such as cubes, cylinders and beams with different proportions of flyash enriched with bacteria is used as the replacement of cement. In this research 40% of cement is replaced with F class fly-ash to produce M40 concrete and the maximum compressive strength of cubes of CF30 is 39.46 N/mm2and maximum flexural strength of beams of CF35 is 4.8 N/mm2. The experimental investigations are carried out to evaluate the improvement of the compressive strength, capillary water absorption and drying shrinkage of RCA concrete incorporating bacteria. The compressive strengths of RCA concrete are found to be increased by about 20% and 35% at the cell concentrations of 10^6cells/ml for the two bacteria. The capillary water absorption as well as drying shrinkage of RCA are reduced when bacteria is incorporated. The improvement of RCA concrete is confirmed to be due to the bacterial mineral precipitation as observed from the microstructure studies such as EDX, SEM and XRD.