Experimental Investigation on Mechanical Properties of Light Weight Concrete with Light Weight Expanded Clay Aggregates (LECA) Exposed to Fire

This study presents an experimental investigation into the mechanical properties of lightweight concrete (LWC) made with lightweight expanded clay aggregate (LECA) when exposed to fire. The investigation focuses on two distinct lightweight concrete mixes, each incorporating partial replacements of 15 and 20% of coarse aggregate with LECA. Additionally, a uniform inclusion of 1% steel fibers was applied to all concrete blends. The primary objective is to assess impacts of fire exposure on the mechanical attributes of these lightweight concrete compositions. The study methodology encompassed the examination of mechanical parameters in a comprehensive range. The objectives are evaluating the reduction in mass, compressive strength, bending tensile strength and split tensile strength at normal temperature conditions and temperatures of 250, 500, and 750 °C. Notably, the mechanical responses of the two distinct lightweight concrete mixtures were compared against those of normal weight concrete (NWC). The results unveiled significant insights into the behaviour of lightweight concrete under fire conditions. Both lightweight mixes demonstrated a reduction in mass as the temperature accelerated. Compressive strength, a crucial mechanical indicator, was found to diminish with increasing temperatures. The investigation highlighted that the reduction in compressive strength was less pronounced in lightweight concrete compared to normal weight concrete, signifying the advantageous attributes of LECA incorporation. Furthermore, the study addressed the behaviour of the lightweight concrete blends in terms of their modulus of rupture, split tensile strength, under varying temperatures. These findings contribute to a deeper comprehension of how LECA-based lightweight concrete maintains its structural integrity when exposed to fire-induced conditions. Overall, this experimental investigation advances an understanding of the mechanical characteristics of lightweight concrete, particularly the influence of LECA and steel fiber on enhancing the fire-resistant of LWC.