Optimised design selection and environmental impact assessment of alternative concrete slab construction methods
Construction material consumption is greater than any time in history. Australia produces approximately 30 million tonnes of finished building products each year, with over 56% of this quantity, by mass, being attributed to concrete and a further 6%, steel. Globally, 23 trillion kilograms of concrete alone is consumed annually with growing population driving increasing demands. From a structural engineering perspective, the use of the most efficient solutions to any given task is poorly considered due to pressures from the architect and/or client. The aim of this research is to investigate and identify the most efficient solution for a known structural outcome. Various slab construction systems were modelled and investigated to determine options through which embodied energy and economic considerations are optimised. The various slab systems available, all have unique properties requiring various slab depths, span lengths and other characteristics which will all affect the final design and consequent performance of a structure from a sustainable perspective. Each slab system delivers its own strengths but the repetitive use of a design favourite often delivers inefficient solutions. The various slab systems investigated in this study include: beam & slab, flat slab and flat plates while concurrently considering the use of conventionally reinforced and post-tensioned concrete. The collaborative pilot study has been conducted to compare the significant material reductions available through various slab systems to improve the sustainability of a given structure. Specifically the study investigates the structural efficiency of a building that has been repetitively designed varying each of the slab systems and concrete types mentioned. These structures are designed in accordance with all relevant Australian standards. Each design is then graded in relation to the sustainable performance of the structure; more specifically its construction costs and overall environmental performance. The outcomes of this study indicate that significant economic and environmental benefits are achievable through the selection of the most appropriate structural system type.
Advances in Structural Engineering and Mechanics (ASEM13)