NMU Concrete Rehabilitation programme
Africoast Consulting Engineers was tasked by the Nelson Mandela University to assess the present state of concrete corrosion by means of a concrete durability survey of the reinforced concrete structures and to make recommendations and compile cost estimates for the required rehabilitation and maintenance of identified affected buildings.
The buildings and structures at the Nelson Mandela University are situated in a severe marine environment and are exposed to corrosive chloride ions from the prevailing salt laden coastal winds. This exposure has over the years resulted in the concentration of the chloride salts within the cover concrete to the steel reinforcement.
A number of buildings and structures at the Nelson Mandela Metropolitan University – Southern Campus were identified to be in need of concrete rehabilitation works to the exposed concrete surfaces, waterproofing and maintenance.
The buildings and structures displayed varying degrees of corrosion related deterioration with visible degradation and concrete spalling which has led to the following primary concerns:
- Long term durability of the structures being at risk.
- Visible degradation of the structures.
- Hidden corrosion to the reinforcing steel that is not externally visible.
- Public Safety
Africoast extracted a total number of 27 x 50mm diameter concrete core samples from selected structural elements within the buildings and structures using diamond-tipped concrete core drilling equipment. These cores were then subjected to various tests such as chloride analysis, carbonation depth testing and cover to steel.
The results of the investigations and diagnostic testing were used to prioritise the rehabilitation work and to prepare cost estimates for budget purposes.
A multi-year concrete rehabilitation programme followed with AfriCoast responsible for all design, specifications, tender and contract documentation, contract administration and construction monitoring.