Structural engineering model of irregular and efficient concrete beams: Application to topology optimized shapes and integrated textile reinforcement

Abstract

Concrete remains one of the most widely used construction materials due to its strength, durability, and availability. However, it is responsible for a large share of the global carbon emissions. Within the 40% of the global emissions attributed to the building sector, 5-8% alone accounts for the production of cement, a key component in concrete. As the construction industry seeks innovations towards sustainable practices, alternative beam designs that improve material efficiency and introduce nontraditional reinforcement systems are emerging as promising potential. However, accurate structural models capable of predicting and validating the performance of these innovative beams are often lacking, limiting their implementation in the industry, primarily due to safety and code compliance. This thesis bridges this gap by developing and validating a structural engineering model to predict the shear and flexural capacities and the deflection of irregular, efficiently shaped concrete beams, including those with alternative reinforcement and formwork. The model discretizes a 3D beam geometry into 2D sections to perform a geometric and structural cross-sectional analysis along the beam’s length. The structural engineering model is applied to two case studies: a topology-optimized steel-reinforced concrete beam and an integrated knit textile reinforced concrete beam, using experimentally measured material properties and beam testing data. The predicted engineering model results are compared against experimental data to validate the model’s accuracy. While the model could accurately capture the behavior of the topology-optimized steel-reinforced beam, it slightly overestimated the strength of the knit-textile reinforced beam. The engineering model for the topology-optimized beam had a close alignment in flexural capacity and had a slightly conservative estimate in shear and deflection due to the nature of the design equations. However, the model showed a minor overprediction in the flexural capacity and deflection of the integrated knit textile beam. Discrepancies in this model were linked to inaccurate material properties, experimental imperfections, and prestressing effects. To ensure complete accuracy and reliability, additional beam analysis using this model is needed. This research advances structural design by offering a tool for predicting the capacity and serviceability of irregular, efficiently shaped concrete beams, including those with alternative reinforcement. This thesis enables designers to validate and optimize their innovative beam designs and support their ideas as sustainable solutions within the concrete construction industry.