Structural Behavior of Concrete Beams Containing Recycled Coarse Aggregates under Flexure

Abstract

<jats:p>The structural behavior of concrete beams containing recycled coarse aggregates (RCAs) was investigated in this study using detailed experimental data. Twelve concrete beams were tested in the experimental program: nine beams with varying RCA contents and three control beams with natural coarse aggregates (NCAs). The parameters for investigating the structural behavior of the RCA concrete beams under flexure were the RCA content (30%, 50%, and 100%) and tensile rebar ratio (0.50%, 0.79%, and 1.14%). The crack pattern of the RCA beams was similar to that of the NCA beams; however, the RCA beams exhibited smaller crack spacing than the NCA beams. The flexural strength was slightly affected by the RCA content. However, the ductility of the beam was not significantly influenced by the RCA content. A comparison of the experimental results and the calculations from the ACI 318 and EC 2 provisions for the flexural strength showed that the current provisions conservatively predicted the flexural strength of the RCA concrete beams.</jats:p>

Sustainable Recycling of High-Strength Concrete as an Alternative to Natural Aggregates in Building Structures

“…Figure 11 shows crack shaping and development in the test samples. Propagation of cracks at different stages was observed by Yang et al [63]. The authors observed a greater number of cracks at the initial cracking stage in the beams with recycled aggregate (RA), compared to the beams with natural aggregate.…”

Selected Strength Properties of Coal Bottom Ash (CBA) Concrete Containing Fly Ash under Different Curing and Drying Conditions

“…The physical properties of the natural coarse and fine aggregates are presented in Table 1. The densities of the natural coarse and fine aggregates were similar at 2.60 and 2.61 g/cm 3 , respectively. The natural fine and coarse aggregates had maximum sizes of 5 and 20 mm, respectively.…”

“…CBA was used as a substitute for natural fine aggregates in the mixtures. The test results in Table 1 show that the density of CBA, at 1.84 g/cm 3 , was lower than that of the natural fine aggregate. The water absorption rate of fine CBA aggregate is the rate of the increase in mass due to water in the pores of the fine aggregate.…”

“…The OPC used in the mixtures was type I with an initial setting time of 45 min and a final setting time of 360 min. The density and fineness modulus of the OPC were 3.15 g/cm 3 and 2800 cm 2 /g, respectively. Additionally, fly ash had a density and fineness modulus of 2.23 g/cm 3 and 3650 cm 2 /g, respectively.…”

“…Moreover, the utilization of waste as a binder in concrete can reduce the amount of cement used, which ultimately reduces the price of the concrete and the carbon dioxide emissions from the cement industry [ 1 ]. Therefore, several studies have been conducted to investigate the utilization of waste materials in concrete [ 2 , 3 , 4 , 5 ]. Among these waste materials, coal bottom ash (CBA) and fly ash are increasingly being released from thermal power plants.…”