EFFECT OF GLASS POWER AS A PARTIAL REPLACEMENT OF CEMENT ON THE FLEXURAL BEHAVIOR OF REINFORCED CONCRETE BEAMS SUBJECTED TO ELEVATED TEMPERATURE

Abstract

Concrete Properties, Mixing, Flexural Behavior, Compressive Strength, Waste Glass Powder, Elevated Temperature.

Deformation and failure processes of reinforced concrete beams, in which cement is partially replaced by finely divided glass powder, under bending under thermal loading. The relevance of this work stems from the search for environmentally friendly methods of glass waste disposal and the improvement of the fire resistance of concrete structures. The study analyzes the physical and mechanical properties of modified concrete, in which glass powder acts as an active pozzolanic additive. Particular attention is paid to changes in the microstructure of the cement paste when heated to critical temperatures ($300–600$°C) and their effect on the adhesion of concrete to reinforcement. The nature of changes in the load-bearing capacity, stiffness, and crack resistance of beams under the influence of bending moments was experimentally determined. It was found that the optimal percentage of cement replacement with glass powder allows not only to preserve strength characteristics under normal conditions but also to slow down the thermal degradation of the concrete structure due to denser particle packing and changes in the phase composition of hydration products. The scientific novelty lies in establishing quantitative relationships between the glass powder content and the residual strength of reinforced elements after a thermal cycle. The practical significance of the results lies in the development of recommendations for the use of recycled glass raw materials to create concretes with improved performance properties for structures at increased risk of thermal exposure. The results of the studies showed that the initial moment of failure for beams with 5%, 10%, and 20% replacement decreased, while for beams with 15% replacement, it increased by 50% compared to the control sample for beams tested at laboratory temperature, which is a promising direction for modern research.

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