Fire-induced spalling of concrete experienced by constructed facilities such as tunnels, buildings and bridges has been shown to cause catastrophic failure, and to lead to huge economic costs and potential loss of life. However, despite the consequences, fire-induced spalling remains one of the least well understood aspects of concrete behaviour. This project aims to develop an improved understanding of fire-induced spalling of modern high-performance concrete, and to find a sustainable spalling-mitigation solution by using fibres recovered from end-of-life tyres. To achieve this, X-Ray Computed Tomography (XRCT) will be used to detect the microstructural changes in concrete due to thermo-mechanical loading and to examine the underlying mechanics of spalling and the spalling-mitigation mechanism of polymer fibre in general and that of the Reused Tyre Polymer Fibre (RTPF) in particular (the latter offering major economic and sustainability benefits). Also, a state-of-the-art fire testing system will provide more controllable heating and hence more reliable and repeatable test results than provided by conventional furnace testing. The high-quality test results collected will form a database for use in this and future research projects. Numerical modelling will be performed, allowing key aspects of the experimentally observed behaviour to be simulated, and preparing the ground for the eventual development of a predictive spalling model. Preliminary design guidance for fire-spalling-resistant concrete with RTPF will also be developed, in order to expedite the uptake of this technology by practitioners.