Materialising structural optimisation of reinforced concrete beams through digital fabrication

Abstract

This study tackles the design, fabrication and testing of truss-like reinforced concrete beams. The paper introduces the strut optimisation method, a Eurocode 2-compliant design procedure which allows to optimise the shear strength of beams. The procedure is embedded in a numerical workflow that automates the design and fabrication of beams. Through a parametric study, potential concrete savings of 24% to 64% are estimated. A digital manufacturing workflow is presented. It is based on the 3D printing of recyclable clay moulds allowing to cast the hollowed-out parts truss-like elements. The fabrication of a 3 m-long prototype illustrates the implementation of the process. Four-point bending tests made on SOM-optimised specimens validate the compliance between the empirical behaviour and the theoretical model, paving the way for wider adoption of materially-efficient reinforced concrete beams.