Parametric Study of Crack Width in Reinforced Concrete Circular Water Tank under Direct Tension as per IS 3370-2009

Abstract

The design of the Reinforced Concrete (RC) water tank was carried out using the working stress method as per IS 3370 (Part-II):1965 in earlier time, which led to heavily reinforced and thicker concrete sections. IS 3370 (Part II) was revised in 2009, in line of Euro codes. As per revised IS 3370 (Part II) limit state method can also be adopted for the design of RC water retaining structures. While following limit state method for design of RC liquid retaining structures, crack width needs to be less than 0.2 mm. Through control of cracking leakage of water and other durability problems can be avoided. For effective design procedure, the parameters affecting the crack width in RC water tank need to be understood. Pure tension cracks are more harmful to the serviceability of the structures that must be treated carefully. The present study aims to understand various parameters affecting crack width calculations for design of RC circular water tanks. By considering water tanks of different capacities with different aspect ratios, relationship is established to select the appropriate geometrical dimensions of the circular water tank as per the provision of IS 3370 – 2009. Such relationships will be very useful to structural engineers for selecting the appropriate geometry and reinforcement details for the RC circular water tank that would ultimately help to keep the crack width under permissible limit. To carry out parametric study a computer program is developed for limit state design of RC circular water tank to speed up the repetitive calculations and to generate database.