Avaliação da resistência mecânica à compressão de amostras produzidas por meio da fabricação aditiva e sua relação com a metodologia de produção

Abstract

The 3D printing of concrete has gained interest in the field of civil construction in recent years as a method of industrialization in the manufacture of elements or buildings. However, the mechanical performance of these printed elements and the production methodology still need to be studied in more detail. Thus, the objective of the present work is to evaluate the influence of different production methods on the compressive strength results of a mixture based on conventional Portland Cement (OPC) for 3D printing, as well as to identify the interference of the printing direction in the results finals. The system was formulated from a systematic review of the literature and based on preliminary tests carried out by the research group. The "flow table" test was used to determine fluidity parameters of the tested mixture. Three production methods were carried out, namely: (i) the production of pre-packaged cubic samples in fresh state; (ii) rectified in a hardened state and (iii) preparation of cylindrical samples with the aid of a cup saw. Compressive strength tests were carried out using an Instron® Press 500HDX-64-67B, with a load application rate equal to 0.05 mm/s in order to determine the influence that the different extraction methods have on the mechanical performance of the printed elements. Finally, the mechanical performance to compression of the samples was evaluated using statistical methods such as ANOVA-TUKEY and Weibull Distribution, where it was demonstrated that cubic samples rectified in a hardened state presented better performance against the compression tests and less variability of the dimensions produced. Based on this work, a production methodology is proposed for 3D printed concrete samples considering the infrastructure currently available at the Civil Construction Materials Laboratory (LMCC) at UFSM.