Análise de Requisitos Técnicos e Econômicos de Pavers de Concreto Geopolimérico

Abstract

In the context of interlocking pavements, Portland cement-based concrete paver is already a commercially established product. Meanwhile, there is pressure to search for more sustainable production alternatives than using Portland cement as a binder. That said, an alternative material to Portland cement that is environmentally and economically viable would have the potential to be competitive. The alkali-activated binder, also known in the literature as geopolymer binder, is produced using mainly industrial waste, such as slag and ash, added with alkaline activators, such as sodium silicate. The mentioned residues act as a precursor, which, when properly activated, produces material that hardens, adheres to aggregates, and gains strength, and may fulfill the role of Portland cement in pavers. However, technical information about these new binders for the development of geopolymer concrete paver are still scarce, making the development of the new product difficult and generating insecurity for investments in its development. This work sought to clarify and analyze the technical and economic requirements for the new product to be competitive in the market. The methodology was based on the investigation and detailing of the manufacturing process of conventional pavers, in order to carry out a cost survey and an identification of technical and/or economic production bottlenecks that can be explored with the development of the new product, composed specifically by BOF steel slag and fly ash as precursors, in addition to soluble silicate and sodium hydroxide as activators. An opinion survey was also carried out with designers and contractors of conventional concrete interlocked pavement, with the aim of evaluating possible improvements that should be implemented for the new product to be competitive. Furthermore, the structuring of the costs of a geopolymeric paver was conducted. It was observed that there is market space for the product, in view of its sustainable bias and its technical feasibility, provided that some production adjustments are made. The hypothesis was validated that the elimination of vibro-pressing, necessary in conventional pavers, has the potential to make the product more viable. However, due to the high price of alkaline activators, it is still necessary to gain scale in production so that the price of the new product is equivalent to conventional blocks. Another possibility for product improvement would be the reduction of the geopolymeric binder content, which tends to reduce the final cost of the product and make its price more accessible.