Strength and dynamic elasticity modulus of rubberized concrete designed with ANFIS modeling and ultrasonic technique

摘要

Rubberized concrete, a composite made with different percentages of waste rubber chips as a partial replacement of coarse aggregates, was investigated in this study by experiments and modeling. For this purpose, different mixtures of rubberized concrete composite were made by replacing 10% and 15% of coarse aggregates by weight (wt%), while incorporating the admixtures, i.e. silica fume and zeolite into the binder, by 10 wt% of cement. Rubberized concrete samples were cured at two different relative humidities (RH) of 0.5 and 1, and different tests were carried out at four different ages. Compressive strength and quasi-static Young's modulus tests were carried out on different mixtures cast in cubic and cylindrical samples, respectively. Ultrasonic technique was employed to measure the pulse velocity and the dynamic Young's modulus of elasticity of the rubberized concrete samples was determined based on compression (Vp) and shear (Vs) wave velocity in rubberized concrete. The dynamic modulus obtained from ultrasonic measurements were compared with those of standard equation, and the correlation and errors were assessed. In order to simulate and predict the compressive strength of the rubberized cement composite in terms of the influencing parameters, namely cement content, silica fume, zeolite, rubber %, RH, and age, adaptive neuro-fuzzy inference system (ANFIS) models were developed, and the prediction results and performance criteria were obtained for training, validation, and testing datasets. Parametric study of the ANFIS model was also conducted to investigate each variable's effect on the compressive strength of the rubberized concrete. (C) 2019 Elsevier Ltd. All rights reserved.