Structural Distress – Campbell Hall – Agnes Scott College
(Winner of The 2009 Georgia Chapter ACI Award)
Background
The Campbell Hall Science Building at Agnes Scott College was opened in 1951 and renovated in 1982.The building construction generally consists of a cast in place conventionally reinforced concrete frame with an exterior brick masonry veneer with clay tile and concrete masonry back up exterior walls. The building was used for Biology, Chemistry, and Physics until it was closed in 2003. Agnes Scott decided to save and restore the building due to its historical significance to the college.
Solution
Based on initial materials testing and a condition survey of the columns, TEC Services categorized the observed distress into high severity and low severity columns. A pilot repair detail for each type of distressed column was developed to assist Agnes Scott in estimating total project renovation costs.During the month of January 2008, Brassfield and Gorrie (contractor) installed temporary shoring and performed exploratory chipping of two select columns (one high severity column and one low severity column) and an eyebrow section along the east elevation of the Campbell Hall building.
Concrete cover* was observed to be less than adequate in both columns. However, the level of corrosion of the reinforcing steel was significantly less in the low severity column. Chloride ion data, previously obtained from TEC Services’ engineers and technicians, correlated locations of high chloride ion concentration to locations of high levels of corrosion of reinforcing steel and high severity distressed columns. TEC Services conducted Ultrasonic Pulse Velocity testing and chloride ion testing at the remaining columns. With the accumulated information, TEC services was able to non-destructively provide repair and shoring details for each of the remainder of the columns.
* Concrete cover refers to the linear amount of concrete between shallow reinforcing steel and the outside surface of concrete members.
