Concrete

Epoxy-Coating protects the steel using several mechanisms. If undamaged, the coating prohibits the passage of chloride ions, thus protecting the steel from corrosion damage. If minor holes or damage are present in the coating and sufficient chloride ions are available in the concrete, then localized corrosion may occur. For the corrosion reaction to proceed, a cathode is required. If all bars are coated, then only very small cathodes are present, substantially reducing the corrosion rate. Tests conducted for the FHWA demonstrated that if both top and bottom mats were coated, the corrosion rates of Epoxy-Coated Steel Reinforcing Bars were 40 to 50 times less than that of similar uncoated bars.

Epoxy-Coated rebar may be used in any concrete subjected to corrosive conditions.

It can also be used instead of SS 316L in expansion joints but we need to take some precautions.

The purity of cement can be checked by following ways :-
1. RUBBING :- Take a small quantity of cement between your fingers and rub it. It must feel smooth while rubbing but if it feels rough than adulteration with sand.

2. HAND INSERTION :- Insert your hand into the cement bag and it should give cool feeling. Hence this cool feeling indicates that there is no hydration reaction is taking place in the bag.

3. FLOAT TEST :- It is tested by throwing a small quantity of cement in a bucket of water. Thus it should sink and should not float on the surface.

4. SMELL TASTE :- Take some quantity of cement and smell it. If the cement contains too much of pounded clay and silt as an adulterant, the paste will give an earthy smell.

5. PRESENCE OF LUMPS :- See that the lumps should not be present in the bag while opening the bag. Thus it ensures that no setting has taken place.

6. COLOUR :- Basically, the cement should be uniform in colour. Generally the colour of cement is grey with a light greenish shade. The colour of cement gives an indication of excess lime or clay and the degree of burning.

7. DATE OF PACKING :- Date of manufacturing should be seen on the bag. It is most important because the strength of cement reduces with age.