Building the African city of the future using more ecologically sustainable materials with a focus on the use of recycled tyre fibre to ‘toughen’ concrete.

Abstract

The title of this thesis is ‘Building the African city of the future using more ecologically sustainable materials with a focus on the use of recycled tyre fibre to ‘toughen’ concrete’. The goal of providing ‘adequate’ housing for all South Africans, as required in the 1996 Constitution, created a major challenge for the country and remains a goal and not a reality. Minimum housing standards have increased and there is now an emphasis on providing sustainable building systems which need to be considered an important part of this challenge. Low-cost housing systems available globally and specifically in South Africa are reviewed and a gap becomes evident in the ‘improved utilisation’ of concrete by the incorporation of industrial waste materials. The key aim and focus of this research are, therefore, to research global trends in sustainable low-cost housing, with an emphasis on finding practical and meaningful improvements that can be implemented, assisting with the sustainability of building materials, whilst also, reducing the quantity of industrial waste going to landfill. As a grounding to the research, a case study is conducted, of an existing ‘state of the art’ construction method, meeting the latest government standard brick housing project regulations, in a ‘deep-rural’ area of South Africa in the KwaZulu-Natal region. This is followed by a survey of South African-approved ‘Alternative Building Systems’, assessed in terms of selected sustainability indicators. Gaining a clearer picture of the current scenario raises the question ‘How Can We Help’ in terms of Academic Research/Materials Engineering, waste-to-landfill reduction and the innovative utilisation of specific waste material properties. In the winding research path of this thesis, the experimental section focuses on the utilisation of polymer fibre from end-of-life vehicle tyres as a ‘performance enhancer’ in concrete. Improving the toughness of concrete for applications where improved crack resistance is required at a low cost. The measurement of the fracture toughness of concrete also brings a dimension not normally covered in traditional concrete development. The output of this thesis, in addition to providing meaningful test data, is intended to leave signposts and open doors for new Engineering graduates to continue to build confidence from meaningful data, supporting Civil and Environmental Engineers in the quest for good housing for all South Africans.