TYPE Original Research PUBLISHED 09 May 2024 DOI 10.3389/fmats.2024.1357094 OPEN ACCESS EDITED BY Chaopeng Xie, North China University of Water Conservancy and Electric Power, China REVIEWED BY Wanhui Feng, Zhongkai University of Agriculture and Engineering, China Ibrahim Saad Agwa, Suez University, Egypt *CORRESPONDENCE Naraindas Bheel, naraindas04@gmail.com Taoufik Najeh, taoufik.najeh@ltu.se RECEIVED 17 December 2023 ACCEPTED 02 April 2024 PUBLISHED 09 May 2024 CITATION Abdullah GMS, Chohan IM, Ali M, Bheel N, Ahmad M, Najeh T, Gamil Y and Almujibah HR (2024), Effect of titanium dioxide as nanomaterials on mechanical and durability properties of rubberised concrete by applying RSM modelling and optimizations. Front. Mater. 11:1357094. doi: 10.3389/fmats.2024.1357094 COPYRIGHT © 2024 Abdullah, Chohan, Ali, Bheel, Ahmad, Najeh, Gamil and Almujibah. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. Effect of titanium dioxide as nanomaterials on mechanical and durability properties of rubberised concrete by applying RSM modelling and optimizations Gamil M. S. Abdullah 1 , Imran Mir Chohan 2 , Mohsin Ali 3 , Naraindas Bheel 4 *, Mahmood Ahmad 5,6 , Taoufik Najeh 7 *, Yaser Gamil 8 and Hamad R. Almujibah 9 1 Department of Civil Engineering, College of Engineering, Najran University, Najran, Saudi Arabia, 2 Department of Mechanical Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, Malaysia, 3 Graduate School of Urban Innovation, Department of Civil Engineering, Yokohama National University, Kanagawa, Japan, 4 Department of Civil and Environmental Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, Malaysia, 5 Institute of Energy Infrastructure, Universiti Tenaga Nasional, Kajang, Malaysia, 6 Department of Civil Engineering, University of Engineering and Technology Peshawar (Bannu Campus), Bannu, Pakistan, 7 Operation and Maintenance, Operation, Maintenance and Acoustics, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, Luleå, Sweden, 8 Department of Civil Engineering, School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, Selangor, Malaysia, 9 Department of Civil Engineering, College of Engineering, Taif University, Taif, Saudi Arabia The use of rubber aggregates derived from discarded rubber tyres in concrete is a pioneering approach to replacing natural aggregate (NA) and promoting sustainable building practices. Recycled aggregate in concrete serves the dual purpose of alleviating the accumulation of discarded rubber tyres on the planet and providing a more sustainable alternative to decreasing natural aggregate. Due to fact that the crumb rubber (CR) decreases the strength when used in concrete, incorporating titanium dioxide (TiO 2 ) as a nanomaterial to counteract the decrease in strength of crumb rubber concrete is a potential solution. Response Surface Methodology was developed to generate sixteen RUNs which contains different mix design by providing two input parameters like TiO 2 at 1%, 1.5%, and 2% by cement weight and CR at 10%, 20%, and 30% as substitutions for volume of sand. These mixtures underwent testing for 28 days to evaluate their mechanical, deformation, and durability properties. Moreover, the compressive strength, tensile strength, flexural strength and elastic modulus were recorded by 51.40 MPa, 4.47 MPa, 5.91 MPa, and 40.15 GPa when 1.5% TiO 2 and 10% CR were added in rubberised concrete after 28 days respectively. Abbreviations: CR, Crumb Rubber; UV, Ultraviolet; TiO 2 , Titanium Dioxide; SG, Specific Gravity; RSM, Response Surface Methodology; CA, Coarse Aggregate; RA, Rubber Aggregates; SP, Superplasticizer; NA, Natural Aggregate; CCD, Central Composite Design; MPa, Mega Pascal; DS, Drying Shrinkage; GPa, Giga Pascal; AP, Apparent Porosity; PC, Portland Cement; ANOVA, Analysis Of Variance; CS, Compressive Strength; UTM, Universal Testing Machine; TS, Tensile Strength; JSCE, Japan Society of Civil Engineers; FS, Flexural Strength; LVTD, Longitudinal Variable Displacement Transducer; ME, Modulus of Elasticity; Ca(OH) 2 , Calcium Hydroxide; NaOH, Sodium Hydroxide; ITZ, Interficial Transition Zone; -S-H, Calcium Silicate Hydrates; SMSS, Sequential Model Sum of Squares. Frontiers in Materials 01 frontiersin.org