Abstract
In the last decade there has been a massive growth for development of concrete infrastructures all around the world. Take into account environmental concerns, concrete technology should direct efforts toward assuring development and fabrication of sustainable and resilient concrete. For this purpose, incorporation of recycled concrete aggregate in concrete products particularly self-compacting concrete (SCC) for structural and non-structural application would be significant achievement. In this study the fresh and hardened properties of SCC prepared by substituting natural aggregates (NA) with recycled coarse aggregates (RCA). In addition, bonding behaviour of reinforced RCA-SCC for structural application was investigated. Moreover, surface treatment of RCA using lithium silicate solution was proposed to investigate its feasibility to improve the fresh and hardened properties of SCC as well as its bonding strength. The mechanical properties including compressive strength, tensile strength and elastic modulus of SCC mixes using untreated RCA and treated RCA (TRCA) were investigated. The results showed an improvement in performance of SCC mixes made with TRCA in compare with the untreated samples. The bond behaviour between SCC made with RCA and steel reinforcement was studied and the relationship between the brittleness and bonding of SCC mixes using untreated RCA and TRCA determined. The effect of surface treatment on the interfacial transition zone (ITZ) between adhered mortar and RCA studied using scanning electron microscope (SEM). It was determined that the treatment of RCA improved the bond at the ITZ through densification. The results gave experimental evidence of the suitability of RCA-SCC for structural use and application in reinforced concrete.
Highlights
Concrete is the most extensively used material in construction industry all around the world and the demand for construction increases as the population grows
The results coincide with the previous studies [27,67,69]. This experimental investigated the incorporation of recycled coarse aggregates (RCA) in the self-compacting concrete (SCC) mixes by implementing the surface treatment procedure using lithium silicate
The results showed that the water absorption of RCA significantly improved after implementing the proposed surface treatment
Summary
Concrete is the most extensively used material in construction industry all around the world and the demand for construction increases as the population grows. Bui et al, [27] proposed using sodium silicate and silica fume to treat RCA and improved its mechanical properties They observed improvement in compressive strength of concrete up to 50%, splitting tensile strength of 41%, and elastic modulus 42.5% in comparison with untreated RCAs. Kazemian, Rooholamini [38] reported that the 28 days compressive strength of concrete with 50% substitution of NA with RCA increased 12.5% after acid treatment along with surface modification with calcium metasilicate slurry. The objective of this study was to investigate the effects of the RCA replacement level and surface treatment using lithium silicate on the bond behaviour of reinforced SCC samples. The last but not least, the microstructure study on the ITZ of the designed RCA-SCC mixes were investigated to evaluate the effect of the treatment method in this study
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.
