GEWI® Micropiles
Single Corrosion Protection
The DYWIDAG THREADBAR® at the core of the pile is surrounded by a cement grout layer of varying thickness. In addition to sealing the bar from moisture, the high ph-value of the cement grout passivates the steel surface of the bar, providing further corrosion protection. Under compressive loads, the grout remains firmly bonded to the bar (without cracking), providing good corrosion protection. Under tensile loads, the bar’s thread deformations create a uniform distribution of fine cracks in the cement grout, the width of which are minimized by the low elongation of the THREADBAR® itself. However, for permanent piles and where the crack width exceeds acceptable levels, double corrosion protection should be used.
1. DYWIDAG THREADBAR®
2. Hexnut
3. Bearing Plate
4. Hexnut
5. Concrete Structure
6. Drilled Hole Cement Grout (Field installed)
7. Coupler
8. Plastic Centralizer
Double Corrosion Protection
Double corrosion protection is provided by placing the THREADBAR® within a corrugated HDPE or PVC sleeve and by filling the annulus between the bar and the sleeve with a non-shrink cement grout, preferably in a qualified shop. This pregrouted THREADBAR® is then assembled, installed and grouted in the same way as the single corrosion protected bar. Double corrosion protection is recommended for permanent tension piles and piles installed in aggressive media.
1. DYWIDAG THREADBAR®
2. Hexnut
3. Bearing Plate
4. Hexnut
5. Concrete Structure
6. Shop grouted plastic Corrugated Sheathing
7. Drilled Hole Cement Grout (Field installed)
8. Coupler with Corrosion Protection
9. Plastic Centralizer
10. End Cap