Net Zero Carbon Concrete Facades: A Catalogue on Low Carbon Concrete Strategies towards Achieving Net Zero

Abstract

Concrete is amongst the oldest yet most successful materials in the building industry due to its consistency, reliability, and simple formula. The ingredients in concrete such as the cement, aggregate, water and sand have remained the same for thousands of years, making it difficult to challenge. Low carbon concrete is one possible solution to reduce the carbon footprint of concrete by replacing the problematic ingredients with more sustainable alternatives. This research is in two parts and plans to explore 5 cement reduction techniques in detail which involve the cement, aggregate, sand, SCM and formwork to reach a net zero carbon concrete panel. The first part involves creating a chart of all the contributing carbon dioxide factors in a precast panel. The chart identifies 11 factors, of which 5 are the primary factors and 6 are secondary. Using the research, a carbon calculator tool shall be designed, identifying a carbon reduction percentage for a panel. In the second part of the research, two panels were created by focusing on one method from the concrete carbon chart, which is using ping pong balls. From that experiment, we learned that redesigning formwork and introducing air voids into the concrete mix, results in a 23% cement reduction. Using Galapagos to have a non-uniform spherical distribution and size results in a 6% cement reduction. Optimizing the formwork is the most straightforward way to reduce the quantity of concrete being used. One option is the bubble deck slab, which will be explored with the ping-pong balls parametrically through Grasshopper for Rhino. Although the research fell short of achieving its net zero goal, it is still possible with more time and research. Future work would be to develop the calculator tool and combine multiple methods in the carbon calculator to reach as close to net zero.