Performance Requirement of Repair System

1. Durability 
2. Protection of steel 
3. Bond with Substrate 
4. Dimensional Stability 
5. Initial Resistance to ENvironment Induced Damage 
6. Ease of Application 
7. Appearance . 

Durability -  Material should be at least as durable as the substate concrete to which it is applied . 

Protetion of steel - Cementitious materials can protect the steel from futther corrosion by their inhibitive effects of increasing the alkalinity of the concrete 

Expoxy resin mortars can give protection against the access of oxygen , moisture & other harmful materials . 

Bond WIth subtrate 

- Must produce an integral repair to prevent of moisture & atmospheric gases at the interface . 

- The bond is greatly enhanced with the use of a suitable bonding aid such as 

- an unfilled epoxy primer for epoxy resins systems & 

- A slurry of Portlan d cement , plus any latex additive for a Portland cement - based repair system . 

Dimensional Stability 

Shrinkage of materials during curing should be kept to a minimum . 

Initial Resistance to Environmentally Induced Damage 

- Partially cured Portland cement repairs can deteriorate from hot weather preventing full hydration of the cement . 

- To prevent this from happening , extra protection during curing time may be necessary . 

Ease of Application 

- Materials should be easily mixed & applied so that they can be worked readily into small gap & voids . 

Apperance 

- A surface coating may be required when apperance is important or when cover to reinforcement is small .