Abstract
As a frequent and serious disaster, the fire will cause serious damage to the building structure when it occurs, so it is very important to study the mechanical properties of structural components after a fire. In this paper, 20 push-out tests of steel reinforced recycled aggregate concrete (SRRAC) columns subjected to a fire were conducted in order to study the bond behavior between I-steel and recycled aggregate concrete (RAC) and the fire exposure was simulated by electrical oven . After this, the change of physical and mechanical properties and the process of mechanical failure of the specimens before and after high temperature exposure were analyzed, and the influence of various parameters on the bond behaviors of SRRAC subjected to elevated temperatures was discussed. At last, the calculation formulas of bond strength were put forward. Test results show that cracks appear on the surface of specimens when the maximum temperature is greater than 400°C, and the higher the temperature is, the more and wider the cracks are. With the increase of temperature, the bond strength of the specimen decreases significantly. When the replacement percentage of RCA is less than 50%, the bond strength increases continuously, on the contrary, the bond strength decreases, and the bond strength of RAC specimens is larger than that of natural aggregate concrete (NAC) specimens. Analysis on the development of bond damage after high temperatures exposure demonstrates that the higher the maximum temperature is, the slower the development of bond damage is. At the same time, the higher the maximum temperature is, the stronger the energy dissipation capacity is.
Highlights
recycled aggregate concrete (RAC) is deemed to be a green concrete to achieve sustainable development of building resources and environment, which can make waste concrete recyclable and save natural sand and stone, with significant social, economic, and environmental-potential benefits
In order to discuss the calculation method of interfacial bond strength of steel reinforced recycled aggregate concrete (SRRAC) subjected to elevated temperatures, this paper takes maximum temperature (T), replacement percentage of recycled coarse aggregate (RCA) (γ ), concrete strength and ratio of height to anchorage length of I-steel (h/la) as the influence parameters of bond strength
According to the measured value of the experiment on bond strength of SRRAC subjected to high temperatures, the regression statistics of ultimate bond strength and residual bond strength are used to analyse the bond strength of SRRAC subjected to high temperatures
Summary
RAC is deemed to be a green concrete to achieve sustainable development of building resources and environment, which can make waste concrete recyclable and save natural sand and stone, with significant social, economic, and environmental-potential benefits. Because recycled coarse aggregate (RCA) is obtained by crushing concrete, its surface is covered with old cement matrix and there are cracks in the process of crushing inside, which. Numerous research efforts (Topcu and Sengel, 2004; Xiao et al, 2012a,b; Behera et al, 2014; Pedro et al, 2014; Li et al, 2015) at the material level have been made to investigate the mechanical properties of RAC, and the results have demonstrated that the inferior characteristics of RCAs (i.e., brittleness of adhesive old mortar, cracks generated during the crushing process, low particle density, high porosity) increase the probability of decreasing the target performance of RAC when compared to NAC at their same strength grade. Many scholars believe that it is feasible to use recycled concrete when engineering structure (Tam et al, 2015; Li et al, 2016)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
