Can a reinforcement steel bar replace with a plastic rebar for construction?

Answer 1

Rebar is used for its high tensile strength. Plastic is not noted for high tensile strength.

Answer 2

Plastic Rebars are better applicable for compression loads, but concrete does the job by itself. Hence Plastic rebars can only be used as a binding material where it is needed. In such applications like mass concreting for for comparetively smaller loads (equipment), plastic rebars shall be used. This will mainly serve the purpose of holding the mass together.

For structure, where tensile loads are there, plastic rebars can not be (should not be) used.

Plastic coated rebars are available in the market for special applications. There are also EPI coated, Corrosion coated and more surface protected or treated steels are available. Usage of such steels are again based on the application.