Estudo comparativo entre massas cerâmicas industriais e aditivadas para uso em blocos cerâmicos.

Abstract

The aim of this work is to contribute to the study of plastic pastes used to make red ceramic products, such as ceramic blocks to be used in civil construction. The specific aims are: a) to characterize physical and mineralogical the industrial ceramic plastic paste; b) to measure the plasticity characteristics with ceramic pastes used for red ceramic and treated with chemical additives; c) to make technological tests with industrial and ceramic paste and treated with additives; d) to compare the results with relationship to the mechanical and physical properties among test samples extruded in laboratory with the industrial masses and the additives; e) to compare the properties mechanic and physical obtained in of industrialized ceramic blocks, with the proof bodies made in laboratory, with the industrial ceramic masses and with additives; f) to make physical and mechanical characterization with industrial ceramic blocks produced in the industry with the same ceramic pastes and compare with the Brazilian norms (ABNT). Five samples of industrial paste used for red ceramic were submitted to a physical and mineralogical characterization (particle size by laser diffraction; thermal analysis and X-ray diffraction) and to technological tests (preliminary and complete) with extruded samples, to determine the physical and mechanical properties with industrial paste and with additives. The results from physical and mineralogical characterization with industrial paste are in accordance with the results from the literature, obtained for plastic paste used in red ceramics. The results from plasticity for the paste with additives showed a significant reduction (21.57%) in the plasticity limit, resulting in a small amount of processing water. The comparison of the mechanical and physical properties showed that the closest values were obtained when the samples were sintered in the laboratory at 900oC. This sintering gives an improvement in the mechanical and physical properties and reaches the minimum values established by the consulted literature. In relation to the analyzed ceramic blocks, all the samples are in accordance with the standard values to water absorption. Regarding the simple compression strength, only a sample did not reach the standard values of the Brazilian norms.