HDGASA V7E1.pdf

Case HistoryCoating thickness readings on the round bar of the seat (152µm) (left), on the side support (117µm) (middle) and on the seat support (114µm) (right).Coating thickness readings on the handrails (above left - 96.2µm and right - 89µm).Removal of contaminants prior to takingcoating thickness readings on seat side bracket.The seat brackets were hot dipgalvanized by the general processwhich was then specified by theprevious national standard, SABS763. Similarly, SANS 121 (ISO 1461)requires that for steel thicknessgreater than and equal to 1,5mm andless than 3mm, the local coatingthickness shall be 45µm and themean be 55µm.Coating thickness readings of seat side bracket (above left - 92.1µm and right - 97.6µm).The coating thickness readings takenon the seat bracket, seat supportbracket and handrail, in accordancewith the photos, still generouslyexceed this requirement.Conclusion andrecommendationThe Railway Stand at Newland RugbyStadium is already 31 years old andthe hot dip galvanized steel seatbrackets and handrails has proved tobe the correct material of choicenotwithstanding effects of a commoncorrosion problem, known asdifferential aeration (or neckingcorrosion) that can be seen onsome of the handrail/concreteinterfaces.Coating thickness readings on seat side support (above left - 149µm and right - 143µm).View of cast in non-galvanized bottom railshowing corrosion products.Corrosion products removed and residualcoating thickness (13.1µm) taken on bottom rail.Hot Dip Galvanizers Association Southern AfricaUnit U4 (Upper Level), Quality House, St. Christopher Road, St. Andrews, BedfordviewP.O. Box 2212, Edenvale, 1610 • Website: www.hdgasa.org.za • E-Mail: hdgasa@icon.co.za