Study on the Corrosion-Inhibiting Effect of Sodium Lignosulfonate Derivatives on Rebar

Abstract

Reinforced concrete structures often fail prematurely due to rebar corrosion.Adding corrosion inhibitors can effectively mitigate rebar corrosion and enhance the durability of reinforced concrete structures.Lignosulfonate， as a green and efficient component， exhibits good corrosion-inhibiting properties.However， its water-reducing effect is bad， and it cannot independently meet the technological demands of modern concrete technology for high fluidity and strength.In this study， sodium lignosulfonate was modified by grafting hydroxyl and carboxyl groups to synthesize sodium lignosulfonate derivatives.These derivatives were then incorporated into simulated pore solutions and cement mortar to investigate their corrosion-inhibiting effects on rebar.Results showed that， in both simulated alkaline chloride environments and mortar accelerated corrosion environments，the sodium lignosulfonate derivatives increased the charge transfer resistance and reduced the corrosion current density，demonstrating significant corrosion inhibition.When the water-cement ratio was 0.35，the flowability of the cement paste with the addition of sodium lignosulfonate derivatives reached 350 mm， with a water-reducing effect comparable to that of polycarboxylate， thus meeting the requirements for concrete flowability and strength.

Keywords

• sodium lignosulfonate； modification； corrosion inhibitor； rebar； chloride ion