Cracking Behavior of Two Way Reinforced Concrete Base Slabs of Telecommunication Towers in Flexure with Varying Reinforcement Details

Abstract

Limited space availability leads to installation of telecommunication towers at roof slabs of residential and commercial buildings. Excessive and early cracking is envisaged in reinforced concrete slabs due to application of 4 points concentrated loads by towers. This affects the serviceability of the reinforced concrete structure. In order to evaluate the flexural behavior of reinforced concrete (RC) slabs, numerical study is carried out by using finite element approach. Four two way RC slabs towers with same geometry and loading conditions (four point concentrated loading corresponding to telecommunication tower load) but different steel reinforcement detailing are analyzed on computer software ANSYS 16.0. Distribution of steel reinforcement is in accordance with the expected bending moment of slabs against the gravity load. Geometric parameters of proposed slab models are applied on crack controlling equation proposed by Nawy and Blair. Results depict that well detailed reinforcement exhibits much better ductile response compared to the one that lacks in detail. Moreover, cracking load has been delayed successfully due to accurate distribution and detailing of reinforcements. It is found that crack width in RC slab is directly influenced by steel bars size and spacing between them. The study also reveals that crack widths in all slabs are within permissible limit recommended by ACI 224R (2001).