Experimental study on bond performance of Eco-Crete and reinforcing steel Mahdi Arezoumandi a,⇑ , Derek Garcia b , Jeffery S. Volz c a Department of Civil and Architectural Engineering, Shahab Danesh University, Pardisan, Qom, Iran b School of Civil Engineering and Environmental Science, University of Oklahoma, 334 Carson Engineering Center, 202 W. Boyd St., Norman, OK 73019-1024, United States c School of Civil Engineering and Environmental Science, University of Oklahoma, 423 Carson Engineering Center, 202 W. Boyd St., Norman, OK 73019-1024, United States highlights  The RAC beams possess 12% lower shear strength compared with the CC beams.  The MCFT method predicts shear strength of the RAC beams very well.  The RAC test results fall within a 95% confidence interval of the CC shear test database. article info Article history: Received 1 October 2018 Received in revised form 24 April 2019 Accepted 27 April 2019 Keywords: Eco-Crete Conventional concrete Bond strength Experimental study abstract An experimental investigation was conducted to study the bond strength of full-scale beams constructed with two different Eco-Crete (low cement content, high cracking resistant concrete with micro and macro fibers) mixes as well as a conventional concrete (CC) mix. This experimental program consisted of nine full-scale, four-point loading beams (three for each mix). The experimental bond strengths of the beams were compared based on code provisions and proposed analytical models. Furthermore, the bond strengths of the beams were compared with a bond database of CC beams. In addition, statistical data analyses (parametric and non-parametric) were performed to evaluate whether or not there is any sta- tistically significant difference between the bond strength of the Eco-Crete and CC beams. Results of this study show that the Eco-Crete beams with micro fibers possess approximately 5% higher bond strength compared with the CC; however, the Eco-Crete beams with micro and macro fibers showed approxi- mately 25% lower bond strength compared to CC beams because of internal honeycombing around the splice region. Ó 2019 Published by Elsevier Ltd. 1. Introduction Global demand for concrete increases every day and cement is a major ingredient in the production of Portland cement concrete. Cement production accounts for approximately 5% of global CO 2 emissions from industry [1]. For this reason, significant efforts have been made to reduce the amount of cement in concrete. One of the solutions is the use of supplementary cementitious materials (SCM) as replacement of cement. As a result, numerous researchers have investigated the use of SCMs such as fly ash, silica fume, slag, and natural pozzolans in the production of concrete. There are a number of studies concerning the effect of SCMs on mechanical properties and durability of concrete, but there are only a limited number of studies on the structural performance of what are termed green concretes (those concretes that possess reduced cementitious contents), including the bond strength between steel rebar and concrete. With regard to low Portland cement concrete bond strengths, Arezoumandi et al. [2] evaluated bond strength of reinforcing steel in concrete beams with 70% of the cement replaced with Class C fly ash. Twelve beams with a rectangular cross section (300  460 mm) and length of 3050 mm with #19 reinforcing steel were constructed. They observed approximately 12% higher bond strengths for the fly ash beams compared to the 100% Portland cement control beams. In another study, Arezoumandi et al. [3] used concrete mixes with 0, 50%, and 70% Class C fly ash as a replacement of cement. Their nine beams (three beams for each mix design) were rectangular (300  460 mm) with a length of 3050 mm. They reported comparable and approximately 10% https://doi.org/10.1016/j.conbuildmat.2019.04.253 0950-0618/Ó 2019 Published by Elsevier Ltd. ⇑ Corresponding author. E-mail addresses: Arezoumandi@shdu.ac.ir (M. Arezoumandi), derek.r.garcia- 1@ou.edu (D. Garcia), volz@ou.edu (J.S. Volz). Construction and Building Materials 215 (2019) 475–481 Contents lists available at ScienceDirect Construction and Building Materials journal homepage: www.elsevier.com/locate/conbuildmat