Bricktech: Assessment for the use of waste in the brick production. Petrophysical characterization of new mix designs and optimization of the firing conditions

Abstract

Bricks are traditional building materials with ancient origin, but that can respond to the important challenges the industrial research is currently called to face, i.e. in reducing energy consumption, in lowering production costs and in improving physical properties and durability of the finished products. The growing demand for a sustainable production addressed research to obtain new materials designed to meet environmental issues and society welfare. This work aims at filling the gap between academic research and industrial development, through a close collaboration between university and industry and the achievement of common objectives. This was possible with the support of a leader company in the production of traditional bricks, SanMarco-Terreal srl (Noale, Italy), which contributed offering technical support, raw materials and consolidate experience in the production of traditional bricks. New mix designs have been developed according to the objectives of Horizon 2020, (https://ec.europa.eu/programmes/horizon2020/), particularly in the field of sustainable use of natural resources, optimization of firing conditions, recycling and gas emission control, in order to satisfy the goals related to the scientific excellence, the societal challenges and the industry leadership. Therefore, the study focused on: 1) the relationship between chemical-mineralogical characteristics and mechanical properties and durability under different stress conditions of bricks already on the market, obtained by different clays and fired at different temperatures (600, 950, 980, 1050°C); 2) the characterisation of the pore system in commercial bricks using a multi-analytical approach, in order to fully understand and describe porosity through a parameterization of the morphological characteristics of pores. This study was also addressed to the optimization of the pore system in fired bricks obtained from different raw materials and fired at different temperatures (600, 950, 1050°C), providing hints for the optimisation of production strategies that can affect the pore system and the brick quality; 3) the study of new mix designs obtained by adding waste material from quarrying activities and industrial sludge for the production of new bricks based on the concepts of reuse and sustainable use of natural resources. The type of waste specifically adopted were: i) trachyte fragments from quarrying activity (Euganean Hills, Italy); ii) sludge resulting from the ceramic industry.