Assessment and repair of distressed kiln piers in a cement manufacturing plant

The observation of apparent structural distress in the form of well-formed diagonal cracks in a number of kiln supporting piers in a cement manufactur ing plant led to a detailed investigation to diagnose the problem facing th e piers and to propose remedial measures to enhance the safety of the piers . The strength assessment of the as-built piers included necessary field in spection and review of the forces acting on the piers. The strength criteri a accommodated the adverse effect of possible constructional discrepancies and the operational loads. The study reveals that the piers are subjected t o excessive torsional moment arising from a possible scenario of partial lo ss of contact of the tyre with one roller, and consequently the piers were required to be strengthened by providing additional wall thickness. The pro posed strengthening scheme: involves jacketing a new concrete wall of 250 m m thickness around the pier. The jacket was connected to the existing wall and foundation by closely spaced epoxy-grouted dowels and was cast by shotc reting using dry mix of Portland cement and aggregates.