The innovation involved in the utilization of Expanded Polystyrene Beads (EPS) is found in its transformative effect on conventional concrete practices. By integrating EPS beads into concrete mixes, a fresh and unique methodology emerges, resulting in a notable modification of the material's properties and the creation of new possibilities for construction and design. Investigating the bending characteristics of Reinforced Concrete (RC) beams containing EPS beads is crucial for progressing our understanding, refining design methodologies, ensuring structural soundness, and endorsing the proficient and conscientious adoption of innovative materials in the construction sector. This research undertook a practical exploration of how the utilization of EPS beads in conjunction with Pozzolana aggregate (PA) influences the flexural behavior of RC beams. A total of twenty-seven simply supported rectangular RC beams were cast, utilizing three distinct and innovative mixtures, and then subjected to two-point load testing until reaching the point of failure. These three mixtures were categorized as follows: a control mix, a mix incorporating only EPS, and a mix combining EPS with superplasticizer. The point of ultimate failure load was determined through experimental tests for all specimens, and the effect of temperatures (300 °C and 600 °C) on the RC beams containing EPS was also investigated. The results indicated that incorporating EPS and EPS with superplasticizers led to a decrease in both concrete compressive strength and density, with reductions of approximately 29.5% and 21.6%, and 11.1% and 15.7% respectively. Furthermore, the inclusion of EPS significantly decreased the ultimate flexural capacity of the beams by around 23.9% compared to the control beams. However, the addition of a superplasticizer with EPS partially mitigated this reduction in capacity. Conversely, beams exposed to 300 °C demonstrated comparable capacity to the unheated control beams, while at 600 °C, a noticeable decline in ultimate load capacity was observed in comparison to the control beams.