Mechanical, microstructure, durability, and economic assessment of nano titanium dioxide integrated concrete

Nanotechnology has emerged as a transformative approach to enhancing the concrete properties. This research examines the impact of nano-titanium dioxide (NT) on the concrete properties. NT was incorporated in varying dosages (0.5%, 1%, and 1.5% by weight of the cement) to assess its impact on strength, toughness, and resilience. The results demonstrated a significant enhancement in mechanical properties, with a peak compressive strength of 65.20 ± 1.03 MPa, a split tensile strength of 3.44 ± 0.17 MPa, and a flexural strength of 9.5 ± 0.47 MPa at a 1.5% NT dosage after 28 days of curing. Furthermore, the long-term performance was notable, as the compressive strength further increased to 75.25 ± 1.10 MPa at 180 days, confirming the sustained strength-gain potential of NT-incorporated concrete. Also, durability assessments were conducted under aggressive conditions, including exposure to 4% NaCl, HCl, and H₂SO₄ for 90 days. Additional tests, including rapid chloride penetrability test (RCPT), surface resistivity, freeze-thaw resistance, and accelerated carbonation, were conducted to assess long-term durability along with its economic feasibility. The NT-incorporated concrete demonstrated enhanced resistance to chloride ingress, acid attack, and elevated temperatures (200-600 °C), with improved modulus of elasticity and fire resistance. Furthermore, durability assessments revealed a noteworthy contrast, i.e., while resistivity tests classified NT-incorporated concretes as having 'very low' chloride penetrability, RCPT values remained in the 'moderate' category. This divergence underscores the need for multiple durability indices in evaluating nano-concretes. Microstructural analyses using scanning electron microscopy confirmed the densification effect of NT, leading to a refined pore structure and improved bond efficiency within the cementitious matrix. Moreover, economic analysis confirms the economic viability of nano-titanium concrete, demonstrating significant long-term savings through service life extension despite higher initial investment. This research highlights the potential of NT in developing high-performance, durable concrete, reinforcing the importance of nanotechnology in construction industry.