Concrete is the main structural material used in the construction of buildings, infrastructure and civil parts of industrial plants. Its production, particularly the manufacture of clinker, requires a considerable amount of energy and involves the emission of various pollutants into the atmosphere. The building and construction sector has introduced numerous substitute materials characterized by excellent technological and environmental performance, but in many applications, the use of concrete remains technically and economically unavoidable. To mitigate the environmental impact of concrete, and at the same time improve the durability characteristics of the finished product, cement mixes have been developed with the partial substitution of clinker with elements such as natural pozzolans or derived from the steel industry.
This study analyses the mechanical and environmental performance of concretes made with cements in which clinker is partially replaced with ash of organic waste. Through the combustion of organic waste, we can have a dual benefit: energy production and a circular waste management strategy. The main objective of this research is to conduct a Life Cycle Assessment (LCA) following a consequential approach to evaluate the environmental performance of concrete incorporating varying percentages of organic waste ash. At the same time, the study aims to assess the mechanical properties of concrete mixtures to determine their suitability in structural applications. A comprehensive LCA is performed to quantify the environmental impacts from the production to the disposal phase of this new type of blend.
Ash production is carried out by the authors within the experimental programme in order to have full control over the operational combustion parameters and to measure the numerous physico-chemical and energy parameters of the process and the ash obtained. Cement is procured from a cement plant capable of producing certified ultra-pure clinker. Starting with these materials, concrete specimens are made to be subjected to mechanical, microstructural and chemical-physical tests to ascertain their strength characteristics in comparison with those of specimens made with ordinary cement.
The results will promote the principles of the circular economy by demonstrating the valorization of organic waste and its potential contribution to reducing the environmental impact of the concrete industry.