Abstract
In this study, compressive and flexural strength, thermal properties, and pore structure of mortars modified with two types of boron waste and different amounts of CuO nanoparticles were investigated. The binders were prepared with 3% of borogypsum or borax waste and nano-CuO at concentration up to 4%. The setting time, compressive and flexural strength at 3, 7, and 28 days, DTA/TG, XRD, BET, and water absorption tests were carried out, and optimal nano-CuO percentages were determined. It was observed that nano-CuO addition in the range 2%–2.5% can improve mechanical properties, reduce the amount of unreacted portlandite, increase water absorption resistance, and decrease the setting time for borogypsum-containing mortars. The optimum nano-CuO replacement ratio changes between 0.5%–1% for borax waste-containing mortars. The results showed that nano-CuO was able to promote hydration reactions, act as a nanofiller, and provide a kernel for nucleation reactions.
Highlights
The use of industrial wastes as supplementary cementitious materials (SCMs) instead of cement, thereby eliminating 5% of the world’s carbon dioxide emissions, has grown in the last decades in line with sustainable and environmentally friendly production approaches
The present study investigated the effects of boron waste and various amounts of CuO nanoparticles on the mechanical and thermal properties and the pore structure of cement mortars, evaluating both their compressive and flexural strength
Borogypsum-containing mortars were prepared with clinker when borax waste–containing mortars were prepared with CEM 42.5 Portland cement
Summary
The use of industrial wastes as supplementary cementitious materials (SCMs) instead of cement, thereby eliminating 5% of the world’s carbon dioxide emissions, has grown in the last decades in line with sustainable and environmentally friendly production approaches. Waste formed during production of borate chemicals (boric acid and tincalconite) have been utilized in construction applications because of their gypsum-like composition and pozzolanic properties [2,3,4]. The study carried out by Targan et al showed usage boron waste with natural pozzolans improves the bending strength of specimens [2]. Topcu and Boga showed that boron waste improves the durability, but decreases the mechanical properties [4]. Literature studies proved boron waste has the set retarding effects [6]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
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 call
