Development of a sustainable concrete incorporated with effective microorganism and fly ash: characteristics and modeling studies

Abstract

The demand of highly sustainable and eco-friendly construction materials with low energy consumption and carbon emission has ever been increasing globally. In this rationale, some modified concretes were prepared via the replacement of the ordinary Portland cement (OPC) by the effective microorganism (EM) and fly ash (FA) at an optimum proportion. The strength performance and microstructure properties of the produced concrete mixes as a function of the EM and FA replacements for OPC were determined. The amount of OPC in the concrete mixes was replaced by the EM and FA at four ratios for the composition optimization. Water was replaced at 5, 10, 15 and 20% by the inclusion of EM solution while FA at 10, 20, 30 and 40% was used to replace the OPC. Using the available experimental test database an Adaptive Neuro-Fuzzy Inference System (ANFIS) was developed to estimate the strength properties of the design mixes depending on each binder mass percentage. Results revealed that the engineering properties of the proposed concrete mixes were improved significantly due to the incorporation of the EM and FA as replacement of the OPC. In addition, the compressive strength of the modified concretes was increased up to 30% and the microstructures were enhanced at an early age because of the substitution of 10% of FA and EM. On top, the concrete formulated with 10% of EM and FA as replacement of OPC displayed enhanced durability as well as reduced porosity, drying shrinkage and carbonation depth of 13.3, 26.9 and 13.4% at 28 days of age, respectively. In short, the replacement of the OPC by FA and EM in the modified concrete was shown to reduce the carbon dioxide emission, energy consumption, and cost. Based on the findings, it was asserted that the designed sustainable concrete mixes may be environmental friendly with reduced green-house gases emission and landfill requirements for the FA wastes.