Study on Optimum Thickness of Post-Tension Concrete Flat Slab with Band Beam
Keywords:Flat slab, Post-tensioned concrete, Band beam, Equivalent frame method, Optimum thicknesses
This paper aims to find the optimum thickness for post-tensioned slabs with band beam using the polynomial optimization method. In the structural analysis, the equivalent frame method using the ADAPT-PT/RC 2015 software is used. In this study, three widths of the band beam were used such as 1/3, 1/4 and 1/5 of the slab width. The span length of the floor slab in each case was 15, 18 and 20 meters, respectively. The value of live load was 200, 300 and 400 kg/m2 which depending on the type of building's usability, including residential, office and parking areas, were used. In addition to the weight of the floor itself, the superimposed dead loads such as 120 and 300 kg/m2 were taken into account in the analysis process. The results of the design are then used to find the appropriate thickness using the polynomial optimization method to provide information for engineers to guide the design and estimate the cost. Based on the analysis, it was found that the correlation coefficient (R2) was 1.0. For residential, office and parking areas, the width of the band beam is 1/3 of the floor width, the suitable ratio of span length to slab’s optimum thickness are 34, 32, and 33, respectively. For the width of the band beam is 1/4 of the width of the slab, the suitable ratio of span length to slab’s optimum thickness are 33, 31, and 32, respectively. In the case of band beam width equal to 1/5 of the width of the slab, the suitable ratio of span length to slab’s optimum thickness is 31, 29 and 30.
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