Effects of Nano-TiO₂on the Toughness and Durability of Cement-Based Material

Abstract

The effects of nano-TiO2(NT) on microstructures and mechanical properties of cement mortars were studied by scanning electron microscopy (SEM), X-ray diffraction (XRD), and mercury intrusion porosimetry (MIP). Results show that 3% NT can remarkably increase the tensile/flexural strengths (i.e., the toughness is improved) and promote the precipitation of AFt crystal. The flexural and tensile strengths have significant positive correlation to the formation amount of AFt. The pores of mortars can be significantly refined and shift to harmless pores by controlling the growth of CH crystal and increasing the hydration reaction rate. The durability of cement-based materials is discussed by testing their water absorption and water-vapour permeability. Results show that the addition of 3% NT can decrease the water absorption ratio by 40–65%, water absorption coefficients by more than 40%, and water-vapour permeability coefficients by 43.9%, indicating that 3% NT can effectively improve the compactness and durability of cement-based materials.

Thermal and Mechanical Properties of Cement Mortar Composite Containing Recycled Expanded Glass Aggregate and Nano Titanium Dioxide

“…This behavior was attributed to the addition of nTiO2 into the cementitious materials, which resulted in an accelerated rate of hydration process. A similar attribute has been reported in previous studies that when nTiO2 is uniformly distributed throughout the matrix, the hydration process and formation of C-S-H gel is accelerated, which results in early strength [32,[47][48]. In the other set of mixes, the effect of nTiO2 inclusion on the compressive strength of mixes was investigated after a different curing time.…”

“…S-H gel by increasing the amount of crystalline Ca(OH)2 at the early age of hydration [32,37]. Ma et al [32] reported 37% and 44% increase in tensile and flexural strength respectively for the samples containing TiO2. In addition, the results indicated that the addition of TiO2 could significantly refine the pores and shift them to the harmless pores.…”

“…Hence, in order to compensate the reduction in mechanical strength and water absorption of cementitious composites integrated with EGA, nanofillers such as TiO 2 can be used. Previous researches have demonstrated that the addition of TiO 2 nanoparticles effectively enhanced the compressive strength and reduce the water absorption of cementitious composites [30][31][32][33][34][35]. Indeed, nTiO 2 fills the nanovoids in concrete, which leads to the increment of compressive strength up to 40% [34,36].…”

“…Indeed, nTiO 2 fills the nanovoids in concrete, which leads to the increment of compressive strength up to 40% [34,36]. Moreover, TiO 2 accelerates the formation of C-S-H gel by increasing the amount of crystalline Ca(OH) 2 at the early age of hydration [32,37]. Ma et al [32] reported 37% and 44% increase in tensile and flexural strength respectively for the samples containing TiO 2 .…”

Nitrogen Oxides Mitigation Efficiency of Cementitious Materials Incorporated with TiO2

“…In Japan, Italy, Belgium, China, and the United States, photocatalytic titanium dioxide (TiO 2 ) is added to sidewalk blocks, precast external building material, and the walls of large buildings such as theaters and stadiums; TiO 2 exhibits anti-fouling, deodorization, and air purification properties. Commercial TiO 2 is used in the construction of such conventional structures [4,5,6,7,8,9,10]. The most common crystalline phases of TiO 2 are rutile, anatase and brookite.…”