Use of Sustainable Materials in Self-Healing Concrete

Abstract

Vulnerability to cracks is one of the major flaws of concrete infrastructure. The need to reduce the repair cost of this defect birthed the need for self-healing concrete. The incidence of cracks on concrete structures is a big threat to the stability of bridges, concrete roads, and other concrete infrastructures. This review assessed the use of self-healing technology on concrete using sustainable material as an active method of healing crack. This was done with the view of improving the stability, strength, and sustainability of infrastructure for national growth. The outcome of the review showed three prominent methods used in self-healing technology, which include autogenous healing, encapsulation of polymeric material, and microbial production of calcium-carbonate (biotechnological approaches). The review also revealed that calcium carbonate is a versatile material that can be used in crack healing for the filling of voids and improves the porosity of the concrete. The success of using the autogenous healing method depends on the diameter of the crack induced in the concrete structure. Additionally, this method can operate independently in different conditions regardless of the crack position. Correspondingly, lowering the water-cement ratio improves the autogenous healing process. The use of encapsulation of polymeric material and microbial production of calcium-carbonate methods showed that the presence of water and humidity is a critical factor to be considered. However, biotechnology using microbial action is prone to the production of ammonium ions (NH4+) through ureolytic activity, which results in nitrogen oxide emission into the atmosphere. Congruently, this may affect the durability of the concrete. Based on the uniqueness of this technology, it is recommended for the construction of sustainable infrastructure now and in the foreseeable future.

Capacitive compressive stress self-sensing behavior of cement mortar and its dependence on the thickness

“…Materials that serve several functions simultaneously are called 'multifunctional' materials [1]. Cement-based composites can provide self-healing [2][3][4][5][6], self-cleaning [7][8][9][10][11], electromagnetic wave shielding [12][13][14][15][16] and self-sensing [17][18][19][20][21] properties as well as being a structural element. The sensing technology electrically reveals the stresses on the structure and allows to comment on the state of live or dead loads on the structure.…”

Bacterial Carbonate Precipitation Using Active Metabolic Pathway to Repair Mortar Cracks

“…According to research, the increase in pH during bacterial carbonate precipitation favors the conversion of atmospheric CO 2 into calcite (CaCO 3 ). As a result, bio-mediated calcification for self-healing could be a viable alternative for CO 2 removal from the atmosphere [ 21 ]. This method for self-healing is relatively safe and eco-friendly.…”