Assessment techniques for concrete lighting columns are less advanced than those for steel columns. This article outlines a recent project for assessing concrete columns for a borough council in North West England, and discusses some lessons from the project. The urban area is located on the coast, and 11,000 of its 15,000 columns are made of concrete. At first, the council wanted to survey all its concrete columns in stages over an extended period. CAPCIS Ltd proposed a survey of a statistically significant sample of the columns. It believes that the results of this survey can be used to target resources for any further detailed inspections and later replacements that are needed. A sample of 500 columns was chosen, on the assumption that about 1% of columns were seriously defective. The major areas of concern for concrete columns are cracking, concrete spalling, and exposure of reinforcing/prestressed wires. The extent of damage to columns was divided into four classes. As up to 90% of the columns were sleeved with galvanised steel, the sleeves also needed to be inspected; all sleeves were in good condition. 80.6% of the columns were in good condition, 4% were good-fair, 2.6% fair, 1.6% fair-poor, 9.8% poor, 1.6% poor-bad, and 0.2% bad. About half the poor, poor-bad, and bad columns were near the sea.
Abstract