The net-zero and sustainability potential of SCC development, production and flowability in concrete structures

Abstract

Climate action around the world has shifted to the potential of global warming contribution from the design and construction of infrastructures, especially those in demand for concrete. Concrete production and use have been identified as contributing to over 5% of the world’s greenhouse gas (GHG) emissions. The main aim of this research work is to critically study the net-zero and sustainability potentials, which the world can leverage on from the development, production, and flowability of the self-compacting concrete. The conventional concrete is made of over 50% of ordinary cement, which contributes to over 7% of the world’s GHG emissions. But, in 1988, a fluidized concrete, which compacts under its self-weight, known as the self-compacting concrete (SCC), was formed and developed to overcome the need for durability, skill, and manpower that were dwindling in Japan at the time. This concrete created a pathway for cement to be replaced partially or totally by certain pozzolanic materials, which function as viscosity modifying admixture (VMA) or high-water reducing agent (HWRA) or microencapsulated phase change materials (MPCM) in the concrete mix. However, research findings have shown that in order for these materials to alter the flowability of the SCC, there has to be reduced yield stress and moderate viscosity for allowable internal friction based on the Bingham model, and this has to be achieved under the same w/c ratio. Fortunately, the implication of the use of these admixtures as replacements for cement is that there is a reduced demand for cement production and use in cleaner concrete production and, as such, a reduced CO2 emission associated with this process.