, raw material cost analysis of epoxy resin coated steel bar, in the factory is the steel surface pretreatment (sandblasting derusting) - steel, electrostatic spraying, water cooling, heating quality inspection in the steel surface coating a layer of protective film of reinforced epoxy resin.

To the steel surface pretreatment is reinforced to seal the indoor do sandblasting derusting, and has a certain roughness, to ensure the caking property of coating and steel. After processing the surface of the harmful material, must not contain any oxide and scarring, sharp corners, affecting the quality of coating surface defects such as burrs. Reinforced immediately after the surface treatment of the qualified and removing dust into the indoor heating device, through the induction heating furnace, the surface reaches a certain temperature. Heated reinforced epoxy resin into the electrostatic spraying chamber in spraying powder, the powder in the steel surface melting form a layer of uniform film, several seconds after curing, cooling and good anti-corrosion protective layer on steel surface inert. Compared with ordinary steel, epoxy resin coated steel bar should be based on the above each working procedure processing and in the steel surface coating a layer of about 0.15 mm to 0.30 mm thick resin paint, this inevitably increase the cost of raw materials. The price of per ton steel shows that the market now than using ordinary reinforced epoxy resin coated steel bar raw material costs about twice as high.

Second, the construction cost analysis but on the whole, the construction of epoxy resin coated steel bar is not very complex, according to the pilot project in our country and the application experience of abroad confirmed:

General quality of the construction team, after technical clarificaiton all can do. But with epoxy resin coating on the surface of the steel bar is easy to damage, therefore, in order to avoid caused by extrusion and friction between sling with reinforced coating is damaged, need to adopt high strength nylon cord or rope sling; Coated steel during storage to avoid ultraviolet radiation causes the fading and wearing away of a coating of needs in its upper cover black plastic sheeting. Therefore in the process of transportation, storage, inevitable to increase the part of the labor and materials. Coated steel bar in the machining process, in order to protect the coating, need to use special casing bending, and doing fuck platform surface overlay on cloth mat cushion; Coated steel bar in the connection process, also need a little more complicated than ordinary steel construction technology; In the process of construction, reinforced coating has damaged parts, also need to adopt special repair solution for repair. All these aspects need to add some construction cost. In a word, in the whole construction process, due to the using epoxy resin coated steel bar, need to increase the construction cost of the whole construction cost increased by 25%.

Three, epoxy resin coated steel bar bond anchorage performance impact on the cost of the factors influencing coating bond anchorage performance of steel has many aspects, mainly including:

1. The influence of coating thickness, when the steel bar diameter, bar diameter is larger and the thicker the coating, the greater the compressive strength reduce.

2. The influence of the steel shape, coating adhesive anchorage performance of steel with the change of the Angle between the ribs with steel axis and screw thread of steep slow change.

3. The influence of the thickness of concrete cover: bond anchorage performance increases with the increasing of coating thickness.

4. The influence of coating on steel bar bending shape: with a hook or bend up better than the straight bar.

5. The intensity of the concrete and the stirrup restraint effect: with the increase of concrete strength, the bond anchorage performance increase, the compressive strength of epoxy resin coated steel bar is proportional to the square root of the strength of concrete; In addition, there are constraints of stirrup compressive strength of epoxy resin coated steel bar relative to did not significantly improve the constraints of the stirrup.

Studies show that the coherence of epoxy resin coated steel bar anchoring strength than the uncoated steel under the condition of general reduced about 10%, not more than 20% lower in the most adverse conditions. Therefore, in order to ensure that coating the bond anchorage between reinforcement and concrete strength, will need to increase the anchorage length of coated steel bar a certain value, and increase the anchorage length is bound to increase the cost of raw materials. Normally reserved than ordinary steel bar anchorage length of anchoring length increased by 25%. To sum up, using epoxy resin coated steel bar increased construction costs, labor accounts for about 25% of the total project cost, one-time investment is very big, but reinforced epoxy coating can effectively prevent the steel bar corrosion, which can effectively reduce the maintenance cost during use, and extend the service life of the structure in more than 20 years, therefore looked from cost-benefit analysis, and has the very good economic benefit and social benefit, especially in the structure of the corrosion environment, the application of epoxy resin coated steel bar technology, its economic benefit and social benefit is very big.