Corrosion Protection Of Micropiles-PPT Presentation

PPT Presentation

Pdf Summary

The presentation examines corrosion protection for self-drilling micropiles, which use hollow steel bars as the drilling rod, grout-injection tube, and load-bearing element.<br /><br />Corrosion is an electrochemical process influenced by soil conditions. Moisture, soluble salts, and soil aeration affect corrosion potential: poorly aerated soils can promote more aggressive corrosion because protective films form slowly. Clays may also crack as they dry, allowing oxygen and moisture to reach buried steel. Because soils vary widely, corrosion behavior is difficult to predict, and steel embedded in grout behaves differently from exposed steel.<br /><br />Common protection approaches include coatings, concrete or grout encapsulation, cathodic protection, plastic sleeves, and sacrificial steel. Sacrificial steel provides a corrosion allowance rather than preventing corrosion. Although recognized in various standards, this approach can be problematic for micropiles: corrosion may reduce the thickness of threaded couplings and compromise their load capacity.<br /><br />The presentation recommends grout encapsulation as the primary protection method for Type E micropiles, drawing on practices used for reinforced concrete. As with reinforced concrete, controlling cracking is important. In highly aggressive soils, additional protective coatings may be appropriate.

Keywords

corrosion protection

self-drilling micropiles

hollow steel bars

electrochemical corrosion

soil conditions

grout encapsulation

sacrificial steel

cathodic protection

protective coatings

threaded couplings