Carbon reduction and strength enhancement in functionally graded reinforced concrete beams

The production of cement alone is responsible for 5–8% global CO2 emissions. This high environmental footprint can be partly attributed to inefficiencies at the material and structural level in concrete structures. Although performance requirements vary spatially within a element, single with same properties typically used ubiquitously, instead being tailored requirements. leads utilisation embodied carbon. research addresses these investigates novel approach enhancement mechanical reinforced Shear-critical elements shear span-to-depth ratio 2.5, longitudinal reinforcement below 1.3% no transverse were tested failure. Functionally graded voids engage preferential internal resisting mechanism reliant on arch action. Volumes that superfluous or detrimental either cast lightweight lower carbon, left unfilled. Novel geometries developed through an innovative fabrication methodology removable inserts, achieving wet-on-wet interfaces between mixes. Net increases achieved all specimens compared conventional prismatic reference beams. In specimen highest performance, overall resistance almost doubled whilst calculated carbon was reduced by approximately third. strategic use functional grading altered cracking pattern development critical cracks particular. initiation, evolution propagation engineered preserve mechanism. Specimens consequently allowed deform divert damage away from arch. As result, brittle failures delayed prevented. most beneficial cases, full plastic flexural capacity yielding steel reinforcement. These findings lead better fundamental understanding damage, behaviour concrete. They demonstrate potential new generation more sustainable structures higher impact.