Exploiting laminated limestone from Cariri Ceará for ornamental and coating purposes has generated about 2.9 million tons of waste, which is discarded of improperly, making it important to search for alternatives to this material. Thus, this work aims to develop artificial stone for wall and floor coating, using laminated limestone waste (Cariri Stone) and a polyester resin. Initially, Cariri stone waste was characterised, and then artificial stone was made with 25% resin and 75% waste, by volume. Water absorption tests and resistance to compression, flexion, abrasion and hard body impact were performed on the composites produced. The results showed that the artificial stone presented water absorption about 5 times lower and abrasion resistance 448% higher than the natural stone, compressive and flexural strength 38.8% and 72.9% lower than the natural stone, respectively, and energy values equivalent to the commercial natural stone in the hard body impact test. It can be observed that the composite produced has a technical potential for use as a coating in civil construction, after adjusting the production process of the artificial stone.

Resumo Os geopolímeros figuram como uma alternativa potencial aos ligantes de cimento Portland em algumas aplicações. Contudo, existem muitas lacunas de pesquisa a serem preenchidas dentro dessa temática. Assim, este estudo teve como objetivo investigar as propriedades reológicas e mecânicas de pastas geopoliméricas à base de cinza volante Classe F ativadas por uma solução de NaOH e Na2SiO3, com relações ativador/precursor de 0,5, 0,6 e 0,7, em massa. Além disso, foram realizadas análises microestruturais e químicas. As propriedades reológicas foram determinadas a partir de ensaios de fluxo com taxas de cisalhamento variando de 0 s-1 a 100 s-1 a 25 ºC. A análise mecânica foi realizada a partir de ensaios de resistência à compressão simples nas pastas endurecidas. Os resultados de resistência à compressão simples indicaram melhores valores para menores relações de ativador/precursor. Nos ensaios de fluxo, o material comportou-se como um fluido pseudoplástico e, com o aumento da relação ativador/precursor, houve redução dos valores de viscosidade aparente. Assim, avaliando-se os resultados mecânicos e reológicos, percebeu-se que a pasta que apresentou melhores propriedades foi a de relação ativador/precursor 0,6.

Ciência -Estudo e ensino -Brasil. 2. Ciência -Aspectos sociais. 3. Ciência -Política e governo. I. Dalazoana, Karine. CDD 303.483 Elaborado por Maurício Amormino Júnior -CRB6/2422 O conteúdo dos artigos e seus dados em sua forma, correção e confiabilidade são de responsabilidade exclusiva dos autores. 2018 Permitido o download da obra e o compartilhamento desde que sejam atribuídos créditos aos autores, mas sem a possibilidade de alterá-la de nenhuma forma ou utilizá-la para fins comerciais. www.atenaeditora.com.br

Portland cement concrete is the most used material in civil construction, but it is a source for emissions of greenhouse gases. In addition, its Interfacial Transition Zone (ITZ) is a point of weakness, which limits its performance and application, generating pathological manifestations throughout its service life, decreasing mechanical and durability properties. In this context, geopolymer concretes, which are a sustainable building material with a much reduced and dense ITZ when compared to ordinary cement Portland materials, arise. However, there is a lack of methodology to evaluate the aggregate-geopolymer interface and objectively evaluate compatibility between such new binder and aggregate particles. In other materials, adhesion tests are performed to obtain parameters related to adhesiveness. Provided that context, this work aims to propose a methodology to evaluate the adhesiveness of aggregates and geopolymer binders. For this, a pull-off test based on AASHTO TP 361 (2022) is proposed, with particular adaptation in specimens preparation. The proposed changes such as: the application of the binder and the use of epoxy glue aimed to guarantee the bonding of pull-off elements (dollies) to a geopolymer binder film adhered to the aggregate and to make the test and its results possible for evaluations. For validation, it was performed for an interface a geopolymer binder based on fly ash and steel slag glued onto two granitic rocks (biotite). For the test according to AASHTO TP 361 (2022), the adhesion between the geopolymer binder and the equipment proved to be insufficient. Then, with the adapted methodology the results were more consistent, in which the specimens showed suitable adhesion for the test. This contributes to an empirical characterization of adhesiveness for these materials, enabling adequate analyses regarding the durability, in order to avoid future pathologies resulting from a weak ITZ and evaluations without huge costs in time and resources.

Portland cement concrete is the most used material in civil construction, but it is a source for emissions of greenhouse gases. In addition, its Interfacial Transition Zone (ITZ) is a point of weakness, which limits its performance and application, generating pathological manifestations throughout its service life, decreasing mechanical and durability properties. In this context, geopolymer concretes, which are a sustainable building material with a much reduced and dense ITZ when compared to ordinary cement Portland materials, arise. However, there is a lack of methodology to evaluate the aggregate-geopolymer interface and objectively evaluate compatibility between such new binder and aggregate particles. In other materials, adhesion tests are performed to obtain parameters related to adhesiveness. Provided that context, this work aims to propose a methodology to evaluate the adhesiveness of aggregates and geopolymer binders. For this, a pull-off test based on AASHTO TP 361 ( 2022) is proposed, with particular adaptation in specimens preparation. The proposed changes such as: the application of the binder and the use of epoxy glue aimed to guarantee the bonding of pull-off elements (dollies) to a geopolymer binder lm adhered to the aggregate and to make the test and its results possible for evaluations. For validation, it was performed for an interface a geopolymer binder based on y ash and steel slag glued onto two granitic rocks (biotite). For the test according to AASHTO TP 361 (2022), the adhesion between the geopolymer binder and the equipment proved to be insu cient. Then, with the adapted methodology the results were more consistent, in which the specimens showed suitable adhesion for the test. This contributes to an empirical characterization of adhesiveness for these materials, enabling adequate analyses regarding the durability, in order to avoid future pathologies resulting from a weak ITZ and evaluations without huge costs in time and resources.