Corrosion Investigation of Rock Anchors Served over 10 Years in Underground Powerhouse of a Hydropower Station

Table 1

Groundwater aggressivity in the tailrace surge chamber.

Item	Test value	Standard value	Description
HCO3^−	2.07 mmol/L	＞1.07 mmol/L	No dissolution corrosion
pH	8.35	＞6.5	No general acidic corrosion
Mg^2+	14.2829 mg/L	＜1000 mg/L	No magnesium sulfate corrosion
SO4^2−	21.945 mg/L	＜250 mg/L	No magnesium sulfate corrosion
Cl^−	2.462 mg/L	＜100 mg/L	Slight corrosion