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Whether the design is done manually or by software, the designer will have difficulty choosing the economic and strength cross section. The designer, in this case, either relies on their experience or resorts to the method of trial and error. Especially for Cantilever beams with a long span as a result of risk deflections, it is exposed. The current theoretical study was performed on rectangular concrete cross sections of different dimensions and subjected to uniformly distributed loads. Based on a previous study, the sections are reinforced with a specific reinforcement ratio. Through an algorithm, Python 3.4 software, and an output file, the permissible deflections for each cross section were calculated according to the ACI 318M-19. Finally, the authors could draw a graph to choose the appropriate cross section for each required beam length in less time and effort.

This study aims to reduce the time and effort required to design an economical spiral staircase according to the latest ACI code. Geometrically, the spiral staircase is a complex 3D structure subjected to three forces and three moments. The values of the six internal stresses generated in each section vary along the staircase and are calculated through a series of long and complex equations. By creating six simplified diagrams of all the variable forces and moments, two locally familiar cases were designed: one with a total angle of 240° and other with an angle of 180°. The created diagrams represent the easiest way to find the locations of the maximum forces and moments. Thus, the structural analysis results will be ready for the design according to approved specifications. After creating algorithms based on ACI-19 requirements, the authors designed both cases and drew the details of the reinforcing bars. In comparison, it is considered more appropriate to construct stairs of 180° in residential and commercial buildings because they meet the architectural requirements and are more economical than those of 240°. [ABSTRACT FROM AUTHOR]

The aim of this study is to find a simple, fast, and economical method for designing RC cantilever beams instead of the traditional methods. Generally, the concrete beams have been designed as T-sections so that their flange has failed within the compression zone, which has embedded with reinforced concrete slab. The structural engineer can select the appropriate section for each span length, but the trial and error method may be used with more effort and time. The economic selection has been become more difficult for cantilever beams especially with a large span due to the significant deflections they have been exposed to. In order to solve this problem, a current theoretical study has been conducted on a number of locally common dropped and inverted T-sections for cantilever RC beams that reinforced with a different reinforcement ratios and their sustained and immediate deflections have been checked according to the ACI -19 provisions. By creating an algorithm and using the Python 3.4 software, the allowable sections have been identified for each required span length. Three curves have been drawn to choose the optimum dimensions for both dropped and inverted T-sections easily. In addition, by comparison, it has been found out that the selection of inverted T-sections has more economy to provide longer spans than dropped sections. [ABSTRACT FROM AUTHOR]