Self-Healing Concrete: Concepts, Energy Saving and Sustainability

Abstract

The production of cement accounts for 5 to 7% of carbon dioxide emissions in the world, and its broad-scale use contributes to climate imbalance. As a solution, biotechnology enables the cultivation of bacteria and fungi for the synthesis of calcium carbonate as one of the main constituents of cement. Through biomineralization, which is the initial driving force for the synthesis of compounds compatible with concrete, and crystallization, these compounds can be delivered to cracks in concrete. Microencapsulation is a method that serves as a clock to determine when crystallization is needed, which is assisted by control factors such as pH and aeration. The present review addresses possibilities of working with bioconcrete, describing the composition of Portland cement, analysis methods, deterioration, as well as environmental and energetic benefits of using such an alternative material. A discussion on carbon credits is also offered. The contents of this paper could strengthen the prospects for the use of self-healing concrete as a way to meet the high demand for concrete, contributing to the building of a sustainable society.

Simulation Study of Hydrodynamic Conditions in Reaction Cell for Cement Biomineralization Using Factorial Design and Computational Fluid Dynamics: Prospects for Increased Useful Life of Concrete Structures and Energetic/Environmental Benefits

“…Calcite is preferable for bacteria-based self-generating concrete due to its greater thermodynamic stability. The different pathways by which microorganisms are able to produce calcium carbonate are broadly classified as autotrophic or heterotrophic [8,9]. The heterotrophic group includes the oxidation of organic salts such as calcium lactate, which is the simplest and safest pathway (Equation ( 1)):…”

“…In cases related to bridges, temperature changes can cause structure thermal expansion, which generates the need for periodic maintenance. Promising investigations regarding self-healing concrete are being carried out with the aim of creating possibilities for eco-sustainable and energy-efficient ways to seal cracks in concrete [8].…”