The Free State University (UFS) Department of Engineering Sciences Green Concrete Project aims to produce user-friendly geopolymer concrete by removing aggressive alkaline activating additives from mixtures, explains professor and project manager Dr . Abdolhossein Naghizadeh.
The potential product will be formulated by optimizing the blend parameters and ingredients based on South African industrial by-products. The green concrete project involves research aimed at producing environmentally friendly concrete from industrial waste.
In green concrete mixes, geopolymer is used as a binder. Geopolymer binders consist of two components comprising a solid raw material and a liquid alkaline activator.
After the raw material is mixed with an alkaline activator, the hardening process begins. To obtain high strengths, the mixture is exposed to high temperatures between 40 ° C and 80 ° C for a maximum of 24 hours.
Although geopolymer concrete technology has been used in limited projects in countries such as China, Australia, France, and the United States, there are issues regarding the complexity of this technology that need to be addressed before its widespread application in industry. It may take some time before this “new” concrete is used more regularly in the construction industry, Naghizadeh explains.
“The main objective of green concrete technology is to minimize the environmental impact caused by normal cement, but the consumption of green concrete based on a geopolymer binder system can also provide economic benefits by using waste, as well as ‘by minimizing energy consumption. The reuse of industrial waste such as fly ash would help in the management of waste in power plants, ”he notes.
The technology of the geopolymer binder as an alternative cement was introduced into the academic world a few years ago. However, certain problems greatly hinder its application in industry.
Some of these issues relate to the complexity of the mix design, the aggressiveness of the activators used, the variety of raw materials found in different countries and the special curing procedures required for this type of concrete.
Based on the importance of the research topic, as well as the existing research capacity within the engineering sciences department of UFS, the research committee decided to play a role and contribute to the development continuation of new technology, known as geopolymer concrete or green concrete. .
“The goals of this lab’s project are to create green concrete formulations based on user-friendly materials and the simplification of the preparation and mixing process. This could introduce a more environmentally friendly and desirable product that can easily be widely used in the construction industry, ”Naghizadeh explains.