再鹼化技術修復火害後鋼筋混凝土特性的影響

The Effect of Electrochemical Realkalisation Reparation on the Characteristics of Fired-Damaged Reinforced Concrete

本研究主要探討利用電化學再鹼技術的修復，對火害後普通強度及高強度兩種鋼筋混凝土性能，包括孔隙率、pH值抗壓強度及粘結力的影響。電化學再鹼化技術使用1 mol/L之Na2CO3及MgCl2水溶液，電流密度1.0 A/m2，通電時間為7天。結果顯示，火害後之鋼筋混凝土經本電化學再鹼化修復後，可提高混凝土內之pH值，以Na2CO3之效果優於MgCl2；可降低混凝土的吸水率，MgCl2之效果優於Na2CO3。兩種電解質對提高火害後混凝土的抗壓強度及粘結力，均沒有顯著的改變。

This study investigated the characteristics of fire-damaged normal strength and high strength concretes after repaired by electrochemical realkalisation (ER). The characteristics included porosity, pH value of compressive strength and bond strength. ER was applied by using 1 mol/L Na2CO3 and 1 mol/L MgCl2 solutions with a current density of 1 A/m2 for 7 days. The results show that the pH value of fire-damaged concrete after repaired by ER can be raised, in which Na2CO3 is better than MgCl2. For reducing water absorption of concrete, MgCl2 is better than Na2CO3. The two electrolytes have no significant improvement on the compressive strength and bond strength of the fire-damaged concrete after repaired by ER.