Assessing the effect of corrosion on optimised low carbon concrete

Global warming is a serious issue that threatens the world and future life of human. The sectors of construction are a major source of carbon emissions, with cement manufacturing making up a major contribution. Low carbon concrete (LCC) is a solution for reducing the emission of net from whole process of manufacturing.

Lowering the buildings embodied carbon dioxide equivalent (eCO2) is a critical response to global and national carbon reduction targets. Globally, the construction industry is developing databases, procedures and tools for assessing and reducing embodied eCO2 in buildings. The construction industry consumes 40% of world energy and contributes 30% of human greenhouse gas (GHG) emissions. Partially replacing clinker, the major element of typical Portland cement, with pozzolanic or latent hydraulic industrial by-products like ground granulated blast furnace slag (GGBS), significantly decreases cement costs by conserving energy in the manufacturing process. It also minimizes CO2 emissions from cement mill and provides low-cost solution to the environmental challenge of industrial waste disposal. In this study, three percentages of GGBS were used (0%, 25%, and 50%).

Corrosion in steel reinforcements is one of the industry's most serious and costly problems. In this study, an accelerated corrosion test was used to determine the correlation between corrosion resistance and optimal strength concrete mixtures. For this study, nine mixed patterns were created and casted into 100 mm cubes and 100 × 100 × 400-mm prism moulds, and 10-mm-diameter rebar was embedded into the concrete prisms for the accelerated corrosion test. The findings of this experiment reveal that resistance typically rises with the strength and percentage of GGBS. This was not the case for all samples, like the 35 MPa samples with 25% GGBS were shown to be more impervious, i.e. to sustain resistance greater than the 40 MPa samples with the same GGBS percentage. This research suggests that the widely held belief that higher-strength concrete always results in greater durability may not always be correct, as the concrete durability is dependent on the cement and the GGBS efficiency.