Bio-Engineered Concrete: A Critical Review on The Next Generation of Durable Concrete

Abstract

Concrete is a prerequisite material for infrastructural development, which is required to be sufficiently strong and durable. It consists of fine, coarse, and aggregate particles bonded with a fluid cement that hardens over time. However, micro cracks development in concrete is a significant threat to its durability. To overcome this issue, several treatments and maintenance methods are adopted after construction, to ensure the durability of the structure. These include the use of bio-engineered concrete, which involved the biochemical reaction of non-reacted limestone and a calcium-based nutrient with the help of bacteria. These bio-cultures (bacteria) act as spores, which have the ability to survive up to 200 years, as they are also found to start the mineralization process and the filling of cracks or pores when in contact with moisture. Previous research proved that bio-engineered concrete is a self-healing technology, which developed the mechanical strength properties of the composite materials. The mechanism and healing process of the concrete is also natural and eco-friendly. Therefore, this study aims to critically analyze bio-engineered concrete and its future potentials in the Structural Engineering field, through the use of literature review. The data analysis was conducted in order to provide gradual and informative ideas on the historical background, present situation, and main mechanism process of the materials. According to the literature review, bio-engineered concrete has a promising outcome in the case of strength increment and crack healing. However, the only disadvantage was its less application in the practical fields. The results concluded that bio-engineered concrete is a new method for ensuring sustainable infrastructural development. And also, it indicated that more practical outcome-based analysis with extensive application in various aspects should be conducted, in order to assess the overall durability.

Insight Into the Microstructural Properties of Bio-Engineered Concrete Matrices & Analysis by Scanning Electron Microscopy

“…For M-5 and M-6 concrete groups, the pulse velocity varied between 3940 ms − 1 to 4630 ms − 1 and 4050 ms − 1 to 4820 ms − 1 with curing age from 7 days to 400 days. It is possibly due to the higher amount of cementing materials, which increased the alkaline environment inside the concrete microstructure and ultimately resulting higher amount of carbonate precipitation by the bacterial cells (Zawad et al, 2021 andZhang et al, 2015).…”

A significant review on the performance of microbial concrete in comportment of diverse nutrients

“…Various alkali-resisting spore-forming bacteria are useful for self-healing: Bacillus pasteurii, Bacillus subtilis, Sporosarcina pasteurii, Enterococcus faecalis, Bacillus sphaericus, Bacillus cereus, Bacillus lentus, Bacillus megaterium (El Enshasy et al 2020). An intrinsic bio-culture (bacteria) material acting as a self-healing agent is applied into the cement matrix to circumvent the cracks (Vijay and Murmu 2020;Zawad et al 2021). Cracks in concrete can be healed in three primary ways.…”

Optimization of Self-Healing Concrete Parameters using Experimental Design Taguchi Method

“…However, the concentration of these bacteria has optimal results at 10 5 cells/ml; if the concentration of bacteria is increased again, it will cause a decrease in the compressive strength value. According to Zawad et al [24], using bacterial culture helps fill the pores between cement and microstructures in concrete to obtain greater compressive strength and become denser. Manjunath et al [25] tested the mechanical properties of concrete, chloride permeability and water absorption and fly ash replacing cement at 10% and 20% with bacterial solutions of 10 3 , 10 5 , and 10 7 cells/ml using Bacillus sphaericus at the age of 28 days.…”