Multi‐response optimization of carbon‐nanotubes concrete: Study on mechanical properties and durability behaviors

Abstract The incorporation of nanomaterials plays a vital role in concrete mechanical properties, durability behaviors, and microstructure. However, existing literature reported significant challenges regarding the optimization and dispersion of these nanomaterials in concrete. This study investigates the effect of optimized multi‐walled carbon nanotube (MWCNT) weight percentages (wt.%) on the mechanical properties and durability of concrete through a two‐phase approach. In the first phase, a multi‐response Taguchi Design of Experiments (T‐DoE) combined with grey relational analysis (GRA) was employed to determine the optimal MWCNT wt.% for concrete mixes. The second phase involved experimental validation of the mechanical properties, chloride penetration resistance, abrasion resistance using sandblasting, and microstructural characteristics of the optimized concrete mixes. The results revealed two effective mix designs with 0.06% and 0.08% MWCNT, achieving compressive strengths of 40 and 45 MPa, respectively, surpassing the traditional concrete strength of 32 MPa and meeting American Concrete Institute and AS3600 standards. The integration of T‐DoE and GRA significantly enhanced compressive strength by modification of microstructure and mechanical properties of cement by nanoparticles through a sustainable development approach %, chloride resistance by 53.6%, and abrasion resistance by 41.1%. Additionally, the optimized mixes demonstrated improved durability against chloride ingress and abrasion over extended curing periods. Field emission scanning electron microscope analysis indicated a robust microstructure with reduced porosity and fewer cracks, highlighting the effectiveness of MWCNT in enhancing concrete performance.