Enhanced shear behaviour of reinforced concrete beams containing Nano-Titanium

Abstract

Nanotechnology is an important field for researchers now and it has changed perceptions, expectations and abilities to control the material world. In this study, the effect of Nano-Titanium (NT) as an addition to cement for concrete mixes is examined on the material and structural levels. The results of standard material tests showed that compressive strength and split tensile strength increase respectively, by ratio 17.91% and 46.29% with 1.0% NT addition, and the rate of increase is no longer significant beyond 1.0% NT. On the structural level, eight reinforced concrete (RC) beams containing NT in various percentages (0.0%, 0.5%, 1.0%, and 1.5%) and 15% silica fume were tested to study the effects of NT addition, shear span to depth ratio (a/d), and spacing between stirrups on shear response. The experimental results are presented for the shear strength, load–deflection, and load–strain relationships. Increasing NT content to 0.5% and 1.0% resulted in an increase in the ultimate load respectively, by 22.3% and 34.7%, and a decrease in the vertical deflection by 31.81% and 45.45% when compared to the control beam. Also, for the constant addition of 1.0% NT, decreasing (a/d) or decreasing the spacing between stirrups resulted in an improved shear strength and stiffness. Furthermore, non-linear finite element analysis (NLFEA) based on ABAQUS software was conducted to validate the experimental results. The validation studies proved that the numerical predictions of the shear strength, deflection and steel strain are in good agreement with the experimental results. Finally, an empirical relation is proposed for the shear strength of RC beams containing NT.