Masonry compressive strength prediction using artificial neural networks

The masonry is not only included among the oldest building materials, but it is also the most widely used material due to its simple construction and low cost compared to the other modern building materials. Nevertheless, there is not yet a robust quantitative method, available in the literature, which can reliably predict its strength, based on the geometrical and mechanical characteristics of its components. This limitation is due to the highly nonlinear relation between the compressive strength of masonry and the geometrical and mechanical properties of the components of the masonry. In this paper, the application of artificial neural networks for predicting the compressive strength of masonry has been investigated. Specifically, back-propagation neural network models have been used for predicting the compressive strength of masonry prism based on experimental data available in the literature. The comparison of the derived results with the experimental findings demonstrates the ability of artificial neural networks to approximate the compressive strength of masonry walls in a reliable and robust manner.- (undefined

EVALUATION OF THE RELATIONSHIPS BETWEEN THE STRENGTH PROPERTIES OF HSC CONTAINING SF AND GP AT A LOW WATER-BINDER RATIO

WOS: 000369121700010In this paper, the effect of high strength concrete (HSC) manufactured with silica fume (SF) and ground pumice (GP) is investigated. Portland cement was replaced with SF, GP and combination of SF and GP up to 25%. 22 different concrete mixtures with these replacement ratios were produced by using 0.25 water-binder ratio. The ultrasound pulse velocity, compressive, splitting tensile and flexural strengths of these concretes were determined. The experimental results show that producing HSC is feasible with SF and GP. Besides, the experimental results indicate that SF and SF in combination with GP can enhance both the short-term and the long-term properties of concrete, whereas GP needs a comparatively longer time to obtain a suitable effect. The results are also supported by scanning electron microscope analysis. The optimum replacement ratios of SF and GP are found to be 15% and 5% of cement, respectively. The relationships between ultrasound pulse velocity, compressive, splitting tensile and flexural strengths are investigated by considering the effects of SF and GP

The influence of elevated temperature on strength and microstructure of high strength concrete containing ground pumice and metakaolin

A laboratory study is performed to evaluate the influence of elevated temperature on the strength and microstructural properties of high strength concretes (HSCs) containing ground pumice (GP), and blend of ground pumice and metakaolin (MK) mixture. Twelve different mixtures of HSCs containing GP and MM were produced, water-to-binder ratio was kept constant as 0.20. Hardened concrete specimens were exposed to 250 degrees C, 500 degrees C and 750 degrees C elevated temperatures increased with a heating rate of 5 degrees C/min. Ultrasound pulse velocity (U-pv), compressive strength (f(c)), flexural strength (f(fs)) and splitting tensile strength (f(sts)) values of concrete samples were measured on unheated control concrete and after air-cooling period of heated concrete. The crack formation and alterations in the matrix, interface and aggregate of HSCs were examined by X-ray diffraction (XRD), scanning electron microscope (SEM) and polarized light microscope (PLM) analyses. XRD, SEM and PLM analyses have shown that, increasing target temperature result with decrease in mechanical properties i.e. U-pv, f(c), f(fs) and f(sts) values. Elevated temperature also results with crack formation, and increasing target temperature caused more cracks. Alterations in the matrix, interface and aggregate were, also observed by these analyses. The experimental results indicate that concrete made with MK + GP blend together as a replacement of cement in mass basis behaved better than control concrete made with cement only, and concrete containing only GP as a cement replacement. (C) 2016 Elsevier Ltd. All rights reserved