Multi-layer, thermal protection and corrosion protection coating system for metallic tendons, especially for external post-tensioning systems

A thermally protected and corrosion protected tendon for concrete construction, comprising in combination a core substrate and a concentric composite laminate, wherein:

• (i) the core substrate is metallic, has a length and extends at least substantially within and is surrounded by the laminate;
• and
• (ii) the laminate has a plurality of concentric layers including:
• (a) an inner layer of a corrosion protective material substantially along and surrounding the length of the core substrate,
• (b) a layer of a first protective plastic coating surrounding the corrosion protective material,
• (c) a layer of a heat-resistive intumescent coating surrounding the first protective plastic coating, and a layer of a reinforcing mesh embedded in the layer of intumescent coating, and
• (d) an outer layer of a second protective plastic coating surrounding the layer of intumescent coating.

A method of protecting a core substrate from heat and corrosion, comprising:

• (a) providing a core substrate having a length;
• (b) affixing an inner layer of a corrosion protective material substantially along and surrounding the length of the core substrate;
• (c) affixing a layer of a reinforcing mesh on the layer of corrosion protective coating;
• (d) affixing a layer of a heat-resistive intumescent coating surrounding the inner layer of corrosion protective material;
• and
• (e) affixing an outermost layer of a protective plastic coating on the layer of intumescent coating.