Condition Survey and Assessment of Concrete Footings in Industrial Plants

Abstract

A condition survey method was developed to assess more than 1,000 footings in an old oil refinery in the Arabian gulf. A data collection sheet was used to record the exposure conditions during operation, the observed distresses, their degree, and the overall condition of the footings. A classification method was used to categorize the footings according to the observed distresses by applying a weighting system to each distress and degree of damage. The degree of confidence in this method was evaluated and was found to range between 85 and 91%. The results showed that 75% of the footings were exposed to cyclic wetting by seawater or combined attack from cyclic wetting with other pollutants. Footings exposed to water or water associated with pollutants suffered 75% of the total reported distresses. Cracking, delamination, and spalling were the most frequent distresses reported, and together they represented 60% of the total. Poor detailing of the joint between the concrete and the equipment chassis and the use of cement mortar with a high water to cement (w/c) ratio in sealing anchor bolts were found to be responsible for many of the steel corrosion distresses.