Author(s)

V. Corinaldesi & G. Moriconi

Abstract

The concept of sustainable development includes the judicious use of natural resources, which in some areas are rapidly depleting, achieved by using industrial by-products and thereby reducing materials waste. In addition, it is necessary to reduce energy consumption that is associated with CO2 and other greenhouse gas emissions. The production of Portland cement also releases large amounts of CO2 into the atmosphere. For this reason supplementary cementitious materials are being used in concrete: one of these materials is fly ash, which is a by-product of thermal power generation. Fly ash exhibits pozzolanic activity, and, if not used, has to be disposed of in landfills at a considerable cost. The use of other non-renewable resources, such as virgin aggregates, also needs to be reduced by recycling rubble from demolished buildings, processed in such a way that they can be used to replace virgin fine and coarse aggregate in concrete. This replacement also allows for reduction in the volume of materials disposed of in landfills. According to the concept of sustainable development, the environmental load of a building must be evaluated throughout its life cycle, from design to construction, maintenance or repair, demolition, and rubble disposal. Therefore, from a holistic point of view, sustainable construction means designing a reinforced concrete structure with appropriate durability during a specified service life. This paper discusses the effect of partial and full replacement of natural aggregates by recycled concrete aggregates (RCA) in a fly ash concrete. Engineering properties and durability performance have been examined for mixtures designed with various proportions of the RCA by mass. Results obtained showed that while incorporating high RCA amount could lower concrete performance, the combined use of RCA and fly ash could allow us to achieve adequate engineering properties and durability. Keywords: durability, fly ash, recycled concrete aggregate, recycling, recycled aggregate concrete, sustainable building.

Keywords

durability, fly ash, recycled concrete aggregate, recycling, recycled aggregate concrete, sustainable building.