Experimental and Numerical Investigation of the Structural, Thermal and Acoustic Performance of Reinforced Concrete Slabs with Balls for a Cleaner Environment

Abstract

This study conducted a comprehensive experimental and numerical assessment to investigate the effect of plastic circular balls placed in the middle of a section of a reinforced concrete slab on strength, ductility, thermal, and acoustic performance. The ball diameter/slab thickness (D/H), grades of concrete, and longitudinal tensile reinforcement ratio (rho) in the slab were selected as the main variables. The variation in thermal and acoustic performance depending upon the ball's diameter was investigated as well. The results showed that the slab's load-carrying capacity, ductility, and energy dissipation capacity did not differ if the D/H ratio did not exceed 0.4; however, significant decreases in these values were observed when the D/H ratio exceeded 0.4. Moreover, the increase in the concrete and reinforcement's strength had a negative effect on the slab with a D/H ratio of 0.8. The experimental results revealed that balled slabs are 3.15 times superior with respect to thermal conductivity and provide 1.38 times more insulation to absorb sound compared to non-balled slabs. In the numerical study of the slabs' thermal performance, the mean surface temperature and heat flux on the slab where the heat transfer takes place decreased as the ball diameter increased. As seen in acoustic models, the level at which the slabs absorbed sound varied depending upon both the diameter of the balls and the sound frequency.