Potential use of ceramic waste as precursor in the geopolymerization reaction for the production of ceramic roof tiles

• Published in: Journal of Building Engineering 2020-05, Vol.29, p.101156, Article 101156
• Main Authors: Azevedo, A.R.G., Vieira, C.M.F., Ferreira, W.M., Faria, K.C.P., Pedroti, L.G., Mendes, B.C.
• Format: Article
• Language: English
• Subjects: Ceramic waste; Geopolymers; Roof tiles
• ISSN: 2352-7102; 2352-7102
• DOI: 10.1016/j.jobe.2019.101156

The red ceramic industry is responsible for generating high amounts of solid wastes around the world from manufacture process failures, such as ineffective firing and issues related to the products transportation. Besides the necessity of clean alternatives to discard the solid wastes, the civil construction industry has been demanding the development of better technological properties new materials. One an example of those new materials is the geopolymeric materials, characterized by the gain of mechanical strength at early ages, high fire resistance, low water absorption and refractoriness. All these characteristics imply that geopolymers are suitable for civil construction applications. The characterization of clay bricks waste, named chamotte, and its use as an alternative precursor to produce geopolymeric materials, such as roof tiles for buildings are the aims of this present work. The chemical characterization, particle size distribution, X-ray diffraction, specific mass, pozzolanic activity index (PAI) and scanning electron microscopy (SEM) were performed, in addition to the technological tests carried out on the geopolymer specimens, such as flexural strength, water absorption, linear shrinkage and apparent porosity. The chemical and mineralogical analysis proved that the waste is rich in silica and alumina, which are fundamental compounds for the geopolymers synthesis. The chamotte also has fine particles and high pozzolanic reactivity. Thus, this waste has great potential to be used as a raw material for obtaining of ceramic roof tiles by means of geopolymeric reactions. •The water content and curing temperature are decisive to improve the characteristics of geopolymers manufactured by pressing.•The curing at room temperature, a longer period should be applied to produce geopolymer with better characteristics.•Geopolymerization of bricks using the ceramic waste as the metakaolin substitute and the pressing is feasible.•The low water absorption presented by the method is also very efficient for roof tiles manufacturing.•The CO2 emission is low compared to firing in the production of ceramics pieces, besides promoting the reuse of the waste.