The concept of using crumb rubber as a partial replacement of natural aggregate in concrete to produce rubberised concrete and reduce environmental impacts has been a subject of research for many years. A plethora of studies have investigated various methods to improve the rubberised concrete strength using different pre-treatment methods for the rubber particles and/or using other additives for general concrete strength enhancement. However, the efficiency and applicability of these methods have been quite inconsistent and in some cases in conflict with each other. This study presents a novel approach to pre-treating crumb rubber particles using thermal treatment at 200 °C before incorporation into concrete. Heating time, rubber size, and rubber content were the variables in this experimental investigation. Scanning electron microscope (SEM) investigation was carried out on both as-received and thermally-treated rubber particles, as well as crumb rubber concrete (CRC) specimens. The results showed promising enhancements in concrete performance compared with the previous work findings. At 20% rubber content using size #40 mesh thermally-treated rubber, the compressive strength recovered by 60.3%.