The effect of TiO2 nanoparticles on water permeability and thermal and mechanical properties of high strength self-compacting concrete

In this work, strength assessments and coefficient of water absorption of high performance self-compacting concrete containing different amounts of TiO2 nanoparticles have been investigated. The results indicate that the strength and the resistance to water permeability of the specimens are improved by adding TiO2 nanoparticles in the cement paste up to 4.0 wt%. TiO2 nanoparticles, as a result of increased crystalline Ca(OH)2 amount especially at the early age of hydration, could accelerate C–S–H gel formation and hence increase the strength of the concrete specimens. In addition, TiO2 nanoparticles are able to act as nanofillers and recover the pore structure of the specimens by decreasing harmful pores. Several empirical relationships have been presented to predict flexural and split tensile strength of the specimens by means of the corresponding compressive strength at a certain age of curing. Accelerated peak appearance in conduction calorimetry tests, more weight loss in thermogravimetric analysis and more rapid appearance of the peaks related to hydrated products in X-ray diffraction results, all indicate that TiO2 nanoparticles could improve mechanical and physical properties of the concrete specimens.