Fibre reinforced concrete with recycled concrete aggregate - Inverse design approach

Abstract

The paper aims at the topic of sustainable building concerning recycling of waste rubble concrete from demolition. The objective of the presented investigations was to verify the proposed breakthrough approach to utilisation of crushed waste concrete in construction of various types of structures. The traditional philosophy of the designing procedure - to find a suitable material for a given structure - is transformed into a new way of designing entitled "inverse design approach" that intends to find a suitable structure for a low-strength porous composite material that is obtained from available recycled rubble concrete. In the first stage, composition of concrete mix optimal from the point of view of mechanical properties, workability and economy is estimated based on the experience of the authors. The keynote is maximising of recycled aggregate use, minimising of cement consumption and providing competitive advantage of the composite made from concrete waste. Properties of the material are determined in laboratory tests. Possible applications of the composite in the construction industry are proposed. Finally, one of the possibilities is selected for verification. The results have shown that the introduced inverse design approach is applicable; it can lead to exploitation of significant amounts of construction waste in a useful way, to substantial savings of primary resources and to reduction of carbon footprint of the construction process.