Contribuição para determinação do módulo de deformação à compressão de aparelhos de apoio elastoméricos simples

Abstract

The elastomers, also known as neoprene, have been widely used in the precast concrete constructions in Brazil, due to its good performance in connections subjected to compression. Thus elastomeric bearing pads are the most commonly used today, their behavior on compressed elements is complex. This complexity of behavior derives mainly from the difference in the properties of the elastomer relative to other commonly used materials and from the variation of stresses and deformations of the elastomers as the compression stresses are increased. In this sense, this study aimed to characterize, through an experimental program, the behavior to the simple compression of the plain elastomeric bearing pads, through the experimental determination of the tangent compression modulus of deformation (modulus of elasticity) and the compression stiffness of these elements. Through the experimental program proposed in this study, as well as the analysis of the tests results, it was confirmed that the calibration of the equation established by NBR 9062: 2017 was satisfactory to evaluate the deformability of the plain elastomeric bearing pads. Furthermore, the tests can be used to verify the conformity of the shear modulus values obtained experimentally, relative to the values indicative of correspondence with the Shore A hardness and, therefore, the quality control of the elastomer. Also, it was possible to adequacy a procedure that could be reproduced with simple equipment, that is, hydraulic actuator with constant force application. Finally, it was found that the higher the speed of application of the load in the test, the greater the rigidity obtained for a plain elastomeric bearing pad.