Stress - strain behaviour of confined nano silica-based concrete

¹ Research Scholar of Civil Engineering, JNTUH CEH, Hyderabad.
² Ex-Professor, JNTUH CEH and Professor, CVR College of Engineering, Hyderabad
³ Professor, Department of Civil Engineering, GRIET, Hyderabad.
⁴ Professor, Department of Civil Engineering, VJIT, Hyderabad.

^* Corresponding author: kumarjyo2003@yahoo.com
Email id: vempada@gmail.com

Abstract

In the present study, the stress-stain behaviour of confined concrete made with nano-silica (nano-SiO₂) were taken up. The stress-strain behaviour was studied for the M30 and M50 grades nano-silica (nano-SiO₂) concrete mixes confined with steel rebars. The confinement was given in the form of steel hoops in the cylinders, 3 hoops (0.8%), 4 hoops (1.1%), 5 hoops (1.3%) and 6 hoops (1.6%). The addition of nano-silica (nano-SiO₂) along with confinement of concrete with steel hoops enhanced the compressive strength, indicating further confinement effect in the concrete. It is observed that the addition of nano-silica (nano-SiO₂) is helpful in lower confinements only. Beyond 1.1% confinement, doesn’t show any effect on compressive strengths. From the stress-strain behaviour of all types of concrete mixes, it is concluded that the ultimate load-carrying capacity and strains at peak stresses are more in nano-silica (nano-SiO₂) concrete with steel hoops for mixes up to 1.1% confinement. The addition of nano-silica (nano-SiO₂) to concrete has increased the ductility in both confined and unconfined states