V&A developed the VANDA® Concrete Corrosion Index Rating System as a means to consistently identify the condition of concrete.

The concrete surfaces (manhole, wet well, and pipe surfaces) are rated according to the following table, which summarizes this concrete rating system. The extent of the concrete damage can vary from Level 1 to Level 4, with Level 1 indicating the best case and Level 4 indicating severe damage.


VANDA Concrete Corrosion Index Rating System

Description

Condition Rating


Level 1

 

No/Minimal Damage to Concrete

  • Hardness: no loss of hardness of mortar
  • Smoothness: no loss of smoothness
  • Cracking: no cracks
  • Spalling: no spalling
  • Reinforcing steel: not exposed or damaged
    (click on thumbnail for larger photo)

Level 2

 

Damage to Concrete Mortar

  • Hardness: some loss of hardness of mortar
  • Smoothness: small-diameter exposed aggregate
  • Cracking: thumbnail-sized cracks of minimal frequency
  • Spalling: shallow spalling of minimal frequency, no related rebar damage
  • Reinforcing steel: may be exposed but not damaged or corroded (click on thumbnail for larger photo)

Level 3

 

Loss of Concrete Mortar/Damage to Reinforcing Steel

  • Hardness: complete loss of hardness of mortar
  • Smoothness: larger-diameter exposed aggregate
  • Cracking: ¼-inch to ½-inch cracks, moderate frequency
  • Spalling: deep spalling of moderate frequency, related rebar damage
  • Reinforcing steel: exposed, damaged and corroded, but rehabilitatable (click on thumbnail for larger photo)

Level 4

 

Rebar Severely Corroded/Significant Damage to Structure

  • Hardness: complete loss of hardness of mortar
  • Smoothness: large-diameter exposed aggregate
  • Cracking: ½-inch cracks or greater, high frequency
  • Spalling: deep spalling at high frequency, related rebar damage
  • Reinforcing steel: corroded or consumed, loss of structural integrity (click on thumbnail for larger photo)