Nicholls Colton Visual & Delamination surveys

Visual and delamination surveys

Visual and delamination surveys allow us to inspect the surface of a structure for any evidence of corrosion, both visually and by hammer tapping accessible surfaces to identify delaminated concrete (shown by a hollow sound being heard).  Defects such as spalling, cracking, water staining (both aged and active) and mineral deposits are recorded on scaled drawings; photographs being taken of the general survey area and individual defects.  Endoscopic techniques can be employed to survey areas hidden from free view.

Concrete is a permeable material and atmospheric carbon dioxide and/or chloride salts can advance towards reinforcement by means of pores in the concrete.  When such fronts reach the level of reinforcement, the alkalinity of the concrete is reduced and can promote the onset of corrosion to this reinforcement.  When this happens, the products of corrosion effectively cause the steel to expand which may delaminate overlying concrete, leading to cracking and eventually spalling of the covering concrete.

Cracks within concrete can also occur from other means such as impact damage and by doing so provide a passage for carbon dioxide and/or chloride salts to reach reinforcement at an advanced rate, causing premature deterioration in the durability of a structure.
Visual and delamination surveys can further identify other conditions to a structure (e.g. failed joints) which can provide, for example, a secondary source of chloride ion contamination from a carriageway above.

Visual and delamination surveys can further identify other conditions to a structure (e.g. failed joints) which can provide, for example, a secondary source of chloride ion contamination from a carriageway above.

CAD drawings of the survey along with photographs are provided within our report for a project.