Southern Africa has a rich history in concrete materials research and construction, and world leading scholars have emanated from our midst. It is a privilege to gather their and visiting international research students, graduates, young practicing engineers and technicians to subject their findings to scrutiny and debate at the 2023 edition of YCRETS.

This Proceedings contains research, technical and review paper contributions by authors from sixteen universities and industries in Southern, West and East Africa. The contributions reflect that circularity in construction is a common vision within the symposium themes of innovation, materials, durability and design. Innovative tests, materials, construction methods and reliability considerations are presented not only for the sake of novelty, but with the intention of enabling maximum inclusion of materials from waste streams as filler, binder, precursor and activator materials. In the Materials theme, the use of waste streams is proposed and appropriate cement-based material technology is presented for the use of construction and demolition waste in concrete and masonry units, and nanotechnology for treatment of waste water as mixing water in concrete. The durability theme comprises of contributions on permeation reducing admixtures, carbonation prediction and chloride-induced corrosion monitoring, and principles of durable over high strength concrete repair materials. Anchor system design, consideration of sustainability in structural reliability design, and a case study of a large concrete hydro power plant structure are presented under the design theme.

All the papers included in the Proceedings have been blind reviewed by members of the Scientific Committee, representing an international panel of academic and industry experts.

The Chairperson of the first YCRETS in 2021, Professor Yunus Ballim, remarked that “cement-based materials will continue to be of dominant use in infrastructure construction. However, this does not mean that these materials can continue to be used in the same manner, mainly because of their significant negative environmental impacts”. The young author contributions of YCRETS 2023 heed his assertion in exploiting vast waste streams, confirming their potential status as commodities in a circular economy and greening of concrete. This demands multi-disciplinary research collaboration, reflected in this Proceedings by co-authorship from subject fields in chemical, civil, environmental, fire, mechanical and aeronautical, mining and structural engineering and information technology. Key fields of chemistry and civil engineering are represented by keynote speakers Emeritus Professor Leslie Petrik of the Department of Chemistry at the University of the Western Cape, and Professor Elsabe Kearsley of the Department of Civil Engineering at the University of Pretoria.


Professor Gideon van Zijl, July 2023