Design and evaluation of doubly-curved shell-like concrete slab elements Pre-stressed structurally optimized elements and their potential to reduce the climate impact

Abstract

The climate impact of the construction sector must reduce to meet the Paris agreement. Horizontal concrete elements make up for a large share of the sector’s impact. This thesis explores doubly-curved shell-like concrete elements and their potential to reduce concrete usage of the sector. The element is explored through design and finite element analysis. The design process starts off with a primary design study of three different slab elements. The geometry is evaluated, and the result is brought into the next study. In the second study, pre-stress, fill and geometrical adaptations are introduced. One slab element is found to have a beneficial structural behaviour. This element is brought to the last design study, where the behaviour of the element is further explored. The element behavior gave the idea for a final pre-stressing case, where the tensile stresses in the slab are reduced enough to be handled by the concrete material. In the 4th and last study, the production and climate impact of the final slab is discussed. The production method derives from some geometrical properties found in the design studies, and the production is realistic. The material climate impact of the final doubly-curved shell-like slab is found to be 30% of the material climate impact for slabs common today.