What About the Grout?

Abstract

The majority of medium to large diameter gravity conduits are rehabilitated by installation of a spiral wound liner. The common approach for these linings is to fill any gap between the host pipe and lining with grout. Although the grout is an integral part of the repair, to date design methods which are governed by buckling typically ignore its contribution, instead relying on the stiffness of the lining alone. Logic indicates that a circular cement ring of grout is strong in compression and difficult to buckle. Full scale testing has confirmed this is the case for grouted spiral linings. This paper details the results of finite element modelling undertaken of the buckling characteristics of a grouted profiled lining to shed some light on the issue from a theoretical perspective with the view that the results can be utilised to develop a more realistic method for the design of these types of linings.