水泥受水化作用所釋放之鹼金屬是提供保護鋼筋之高鹼性環境來源之一。當混凝土孔隙水之PH值大於12時，鈍態膜在鋼筋表面形成而不易受到腐蝕，但是此PH值易造成鹼骨材反應加速。若混凝土受碳化或有害性物質侵入造成PH值小於9或氯離子超過臨界量時，則將破壞鋼筋鈍態膜而加速腐蝕反應。本研究即針對以上之邏輯，擬以添加礦物摻料及腐蝕抑制劑的方法，謀求改善混凝土滲透性、緻密化孔隙結構及提供適當鹼性環境，並利用Cl(上標 -)/OH(上標 -)比值關係，探討混凝土中摻料之化學性質對鋼筋防蝕潛能之影響。

The alkali metal released by the hydrated cement after hydration was one of the sources of alkali environment for protecting the steel. When the PH value of the pore water in concrete was greater than 12, passive film would form on the surface of steel to protect it from corrosion. However, the great PH value would accelerate the reaction of alkali aggregate. If the PH value was less then 9 due to the carbonation of concrete or the invasion of detrimental matters or the [Cl(superscript -)] concentration exceeded the critical value, the passive film on steel bar would be damaged, and the corrosion would accelerate. Aimed at the previous logic, this study intended to improve the permeability of concrete, to densify the pore structure, and to provide a proper alkali enviromment by adding mineral admixture and corrosion inhibitor. In addition, the ratio of Cl(superscript -)/OH(superscript -) was employed to understand how the chemical characteristics of admixtures in concrete affected the anti-corrosion potential of steel.