Effect of TiO 2 , Al 2 O 3 and CaCO 3 nano-additives in singular, binary and ternary forms on the mechanical, thermal and microstructural propertites of fly ash supplemented cement matrix N. Vanitha a , T. Revathi a , R. Gopalakrishnan a,⇑ , R. Jeyalakshmi b,⇑ a Department of Chemistry, SRM Institute of Science and Technology, Kattankulathur 603203, India b Department of Physics and Nanotechnology, SRM Institute of Science and Technology, Kattankulathur 603203, India article info Article history: Received 22 February 2021 Received in revised form 26 March 2021 Accepted 7 April 2021 Available online xxxx Keywords: Nano-materials Compressive strength Pozzolanic reaction Fly ash blended cement Thermal conductivity abstract In this paper, we focus on how nanoadditives such as nano-Al 2 O 3 , nano-TiO 2 and nano-CaCO 3 modify the mechanical and capillary permeability of fly ash cement mortars (5:1). When nanoadditives are added in proportions of 2%, 4% and 6% of the binder volume, hydration products are generated, and thermal con- ductivity and microstructure of cement mortars undergo a change. Mechanical property measured at 7, 28 and 90 days are measured to understand the underlying pozzolanic reaction and filling effect. The experimental findings reveal that the form and quantity of refractory chemicals in mortar production had an impact hardened matrix at the early age between 7 and 28 days, but thereafter, there is only a marginal strength gain. Nano-Al 2 O 3 and nano-CaCO 3 (at 2% of binder volume) additives were able to increase the mortar strength to the extent of 27% of the 28-day compressive strength at 7 days. The addi- tion of 2% nano-TiO 2 did not produce this effect. The addition of 6% nano-Al 2 O 3 + nano-CaCO 3 in binary and 6% nano-TiO 2 + nano-Al 2 O 3 + nano-CaCO 3 blend in ternary combinations produced a phenomenally positive effect on the compressive strength with the reduction of capillary permeability at 90 days of set- ting. The X-ray diffraction patterns of these matrices compared with control showed a clear evidence of reduction of CH growth. Formation of a compact binding gel can be observed in scanning electron micro- scopic (SEM) pictures. A dense microstructure of binary and ternary nano additive mixes is establish to be favourable in decreasing the thermal conductivity of fly ash blend cement mortar measured at 30 °C. The combination of non-siliceous nano-size materials such as nano-Al 2 O 3 , nano-TiO 2 and nano-CaCO 3 in small quantities have an impact on the pozzolanic reaction with continual strength gain and are effective in counteracting the shortcomings of fly ash blended with cement mortars. Ó 2021 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International e-Confer- ence on Advancements in Materials Science and Technology. 1. Introduction The increasing eco-friendly sustainability concerns in the cement production necessitated the usage of supplemented cementitious materials (SCM), especially fly ash (FA), which is pro- cured from coal thermal power stations. Extensive research on adding fly ash as a binder material in cement brought out encour- aging results on the performance of the ordinary Portland cement system. So pozzolana cement is now employed in regular construc- tion due to its technical, economical and environmental benefits [1]. Blending cement with fly ash leads to better compressive strength properties and increases its durability. Though, due to low early age characteristics, the proportion of fly ash is kept at less than 30% due to its role in low reactivity [2]. In order to increase the early age properties of cement composites incorporat- ing fly ash, researchers have studied other factors, like reducing the particle size of fly ash [3], treatment with hydrated lime [4], set accelerator [5] and blending with other SCM like silica fume [6] and metakaolin [7]. As various efforts are ongoing to enhance the properties and performance of fly ash cement mortars, the focus of the study is on the addition of nanomaterials to fly ash mortar as they have excellent reactivity and wide surface area. In nanotechnology, a nanoparticle is an elementary building block and includes up to thousands of atoms in the 1–100 nm clus- https://doi.org/10.1016/j.matpr.2021.04.088 2214-7853/Ó 2021 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International e-Conference on Advancements in Materials Science and Technology. ⇑ Corresponding authors. E-mail addresses: gopalakr@srmist.edu.in (R. Gopalakrishnan), jeyalakr@srmist. edu.in (R. Jeyalakshmi). Materials Today: Proceedings xxx (xxxx) xxx Contents lists available at ScienceDirect Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr Please cite this article as: N. Vanitha, T. Revathi, R. Gopalakrishnan et al., Effect of TiO 2 , Al 2 O 3 and CaCO 3 nano-additives in singular, binary and ternary forms on the mechanical, thermal and microstructural propertites of fly ash supplemented cement matrix, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2021.04.088