Electrochemical Chloride Extraction Effect of Steel Slag Concrete

Electrochemical chloride extraction (ECE) technology was used to treat concrete, the free chloride ion content in steel slag concrete and the bonding strength of reinforced concrete interface were tested. XRD diffraction was used to analyze the phase of the reinforced concrete interface, and the effect of steel slag on the dechlorination efficiency of concrete and the bonding performance of the reinforced concrete interface were studied. The results showed that with the increase of steel slag content, the efficiency of chlorine removal first decreased and then increased. Under the conditions of current density of 3 A/m² and power-on time of 30 d, the dechlorination efficiency of concrete with different steel slag content (10%, 20%, 30%, 40%) was 29.5%-48.5%, which was lower than that of ordinary Portland cement (OPC) concrete (51.7%). ECE treatment would reduce the bond strength of the reinforced concrete interface. The bond strength loss rate of concrete with steel slag content of less than 30% was lower than that of OPC concrete, while the bond strength loss rate of concrete with steel slag content of more than 30% increased rapidly. After ECE treatment, the content of C-S-H at the interface of reinforced concrete decreased, and Ca(OH)₂ crystals increased. With the increase of steel slag content, the increasing trend of Ca(OH)₂ crystals slowed down.