Purpose: The purpose of the study was to investigate the spalling phenomenon in ultra-high performance fibre reinforced concrete (UHPFRC) beams on exposure to a standard fire curve (ISO 834) under a sustained load. Design/methodology/approach: The variables in this study were steel fibre dosage, polypropylene (PP) fibres and loading levels. The research investigated seven beams – three of which contained steel fibres with 2 vol.%, another three had steel fibres with 4 vol.% dosage and the seventh beam had a combination of steel fibres (2 vol.%) and PP fibres (4 kg/m3). The beams were tested for 1 h under three loading levels (20, 40 and 60 per cent) based on the ambient temperature ultimate flexural strength of the beam. Findings: Spalling was affected by the loading levels; it exacerbated under the load level of 40 per cent, whereas under the 60 per cent load level, significantly less spalling was recorded. Under similar loading conditions, the beams containing steel fibres with a dosage of 4 vol.% spalled less than the beams with fibre contents of 2 vol.%. This was attributed to the additional tensile strength provided by the excess steel fibres. The presence of PP fibres eliminated spalling completely. Originality/value: There is insufficient research into the performance of UHPFRC beams at elevated temperature, as most studies have largely focussed on columns, slabs and smaller elements such as cubes and cylinders. This study provides invaluable information and insights of the influence of parameters such as steel fibre dosage, PP fibres, loading levels on the spalling behaviour and fire endurance of UHPFRC beams.
Purpose: Informal settlements are inherently unstructured in nature, lack adequate services, regularly have high population densities and can experience social problems. Thus, fires can easily propagate rapidly through such areas, leaving thousands homeless in a single fire. The purpose of this paper is to present an appraisal of various interventions and strategies to improve fire safety in informal settlements in South Africa (globally, similar settlements are known as slums, ghettos, favelas, shantytowns, etc.), considering aspects of both technical suitability and social suitability. Design/methodology/approach: This paper focusses on three specific aspects: ignition risk management, active fire protection interventions and passive fire protection interventions. These are presented within a framework to outline how they may mitigate the impact of fires. Findings: Often “solutions” proposed to improve fire safety either lack a sound engineering basis, thus becoming technically inefficient, or do not consider social circumstances and community responses in settlements, thereby becoming practically, socially or economically unsuitable. It must be understood that there is no “quick fix” to this significant problem, but rather a combination of interventions can improve fire safety in general. A broad understanding of the various options available is essential when addressing this problem, which this paper seeks to provide. Practical implications: This paper seeks to provide an overview to guide policymakers and organisations by illustrating both the advantages/benefits and disadvantages/challenges of the interventions and strategies currently being rolled out, as well as potential alternatives. Originality/value: A broad but succinct appraisal is provided that gives insight and direction for improving fire safety in informal settlements. It is hoped that the challenges associated with the fire safety interventions discussed can be addressed and improved over time.