Specimen size and shape effects on strength of concrete in the absence and presence of steel fibers

Abstract

In this research, the effects of size and shape on compressive and splitting tensile strength of fibrous and non-fibrous concrete specimens with different characteristic strength were investigated. With this aim, both fibrous and non-fibrous 10 different concrete mixtures with 0.3, 0.4, 0.5, 0.6 and 0. 7 Water/Cement ratio were prepared. In the fibrous mixture specimens, the total amount of steel fibers to 1% by total volume. In the entire specimens, 42.5 R type Portland cement were used as bonding elements while crushed lime stones in 3 sizes were added to the mixtures. Furthermore, to evaluate the influence of size and shapes over specimens’ strength, for each concrete mixtures two 10 cm and 15 cm cubic specimen beside two 10×20 cm and 15×30 cm cylindrical specimens were prepared as well. The prepared specimens were subjected to compressive and splitting tensile tests. The results showed that, regardless of the fiber amount and specimens’ shapes, the decrease in specimens’ size resulted in higher strength. But in the high ratio of Water/Cement and fibrous mixtures, the mentioned behavior was not observed.

Predictive Modeling and Experimental Validation for Assessing the Mechanical Properties of Cementitious Composites Made with Silica Fume and Ground Granulated Blast Furnace Slag

“…The reported database for CS contains 248 data points obtained from cubic specimens with a size of 150 mm and 400 data points obtained from standard-size cylindrical samples (150 mm in diameter and 300 mm in height). However, according to previous experimental investigations, the length-to-diameter ratio (L/D) affects the strength properties of concrete [63]. Therefore, for the sake of homogeneity, all of the data points were normalized in standard cylindrical form.…”