钢筋在水泥-蔗渣灰-矿粉海砂砂浆中的腐蚀行为

Corrosion Behavior of Steel in Cement-Bagasse Ash-Slag Sea-Sand Mortar

研究了水泥?蔗渣灰(SCBA)?矿粉(BFS)三元胶凝材料组成对海砂砂浆中钢筋交流阻抗谱、开路电位和腐蚀电流密度的影响,同时测定了砂浆的氯离子含量、pH值和水化产物。结果表明:随着蔗渣灰掺量增加,钢筋的腐蚀速率和[Cl^(-)]/[OH^(-)]值增大。随着矿粉掺量的增加,钢筋的腐蚀速率明显减小,[Cl^(-)]/[OH^(-)]值在养护早期增大,28 d后略微减小。复掺15%蔗渣灰和15%矿粉时两者具有较好的协同作用,有效增大了保护层电阻和电荷转移电阻,提高了钝化膜的稳定性,使砂浆中的钢筋腐蚀速率相比参照组降低了31.86%,其钢筋的抗腐蚀能力最佳。

Effect of cement mixture containing bagasse ash(SCBA)and slag(BFS)on the corrosion properties of steel in sea-sand mortar was investigated.The electrochemical impedance spectra,open circuit potential,and corrosion current density of steel were determined,and the chloride ions content,pH value and hydration products were measured.The results show that an increase in bagasse ash content leads to an increase in the corrosion rate of steel and[Cl^(-)]/[OH^(-)]value.However,an increase in slag content can reduce the corrosion rate of steel,and cause that the[Cl^(-)]/[OH^(-)]value initially increases and slightly decreases after 28 d.The addition of 15%bagasse ash and 15%slag has a positive synergistic effect,effectively increasing the resistance of mortar protective layer and charge transfer resistance,improving the stability of the passivation film,and reducing the corrosion rate of steel in the mortar by 31.86%,compared to the reference group.The optimum corrosion resistance of the steel can be obtained.It is indicated that the use of a cement mixture containing bagasse ash and slag can effectively improve the corrosion resistance of steel in sea-sand mortar.