Microstructure and Strength Properties of Sustainable Concrete Using Effective Microorganisms as a Self-Curing Agent

In practical applications, problems related to proper curing arise for inclined structural elements, especially in skyscrapers, wherein concrete is very thick. To overcome this problem, the implementation of self-curing technology using varieties of smart materials has become significant. Based on these factors, this study determined the impact of effective microorganisms (EMs) as a new self-curing agent on the microstructures and strength properties of sustainable concrete. Five concrete mixtures were prepared with various EM content (5, 10, 15, 20, and 25%) as water replacement under air-curing condition. The workability of the concretes was found to increase with the increase in EM contents from 0 to 25%. In addition, concrete designed with 10% of EM achieved the highest compressive strength (42 MPa) after 28 days of aging as opposed to the control specimen (35 MPa). The microstructures of the concrete made with 10% of EM revealed very a compact network, fewer voids, and formulation of dense C-S-H gel. Based on the results, the proposed EM may be implemented as a self-curing agent to achieve high-performance sustainable concretes beneficial for the construction sectors.