EFFECT OF SILICA FUME IN THE PROPERTIES OF LIGHTWEIGHT CONCRETE WITH EXPANDED CLAY

• Autor(a) principal: Souza, Marina Costa de
• Data de Publicação: 2021
• Outros Autores: Davi, Amália de Sousa, Fraga, Yuri Sotero Bomfim
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Repositório Institucional da UFSC
• Texto Completo: https://ojs.sites.ufsc.br/index.php/mixsustentavel/article/view/4591; https://repositorio.ufsc.br/handle/123456789/246599
• topic: Lightweight concrete; Silica fume; Expanded clay; Efficiency factor; Concreto leve; Sílica ativa; Argila expandida; Fator de eficiência; Concreto leve

The use of lightweight concrete (LC) represents a great challenge due to the reduction of the mechanical properties caused by the substitution of conventional aggregate for light aggregate. In view of the above, this paper aimed to verify the effect of the addition of 10% of silica fume (SF) in mixtures of concrete with replacement of 50% and 100% of the volume of crushed stone by expanded clay (EC). In the fresh state, the content of superplasticizer additive needed to obtain a consistency of 100±20 mm was analyzed using the slump test. In the hardened state, tensile and compressive strengths were analyzed at 3, 7 and 21 days of hydration. A decrease in the mechanical performance of the concrete was observed when the gravel was replaced by EC. Despite this decrease, lightweight concretes resulted in greater strength/weight ratios. It was observed that the addition of SF significantly improved the mechanical properties of lightweight concrete. Thus, it is possible to conclude that the addition of SF can compensate for the loss of mechanical performance caused by the replacement of conventional coarse aggregate with expanded clay, without the need to increase the amount of cement in the mixture