Characterization and Steel Corrosion of Cement Produced from Incinerator Ashes

焚烧炉灰烬水泥的表征及钢材腐蚀

基本信息

批准号：
11650465
负责人：
TORII Kazuyuki
金额：
$ 2.5万
依托单位：
Kanazawa University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

项目摘要

Ecocement is a new type of hydraulic cement produced from incinerator ash. However. the incinerator ash contains large amounts of chloride, which, if not removed during the production process, is expected to accelerate the corrosion of steel bars when ecocement is used in reinforced concrete structures. The chlorides can be removed in the production process but at a high cost. Two types of ecocement have been produced, a high chloride type (type I) and a low chloride (type II). This paper investigates the corrosive behavior of steel bars embedded in the mortars containing both types of ecocement, cured under and exposed to wetting and drying cycles. Corrosion of the mild steel bars was monitored by halfcell potential, polarization resistance, and AC impedance measurements. The relative performance of the two types of ecocements with respect to the corrosive behavior of the embedded steel bars was discussed.From the results, the following conclusions could be drawn.(1) Steel bars embedded in mortars of high-chloride type ecocement is more susceptible to corrosion than that of low-chloride type one.(2) Carbonation accelerates corrosion of steel bars embedded in the mortars of both ecocements, although the effect is higher in high-chloride type than in low-chloride type.(3) Electrical measurement yields a good result in the monitoring of corrosion of steel bars embedded in cement mortars.(4) In both types of ecocement, the extent and severity of the corrsion of the embedded steel bars depend on the water to cement ratio, the higher the water to cement ratio, the greater the severity of corrosion.

生态水泥是一种以焚烧炉灰为原料生产的新型水凝水泥。然而。焚烧炉灰中含有大量氯化物，如果在生产过程中不去除，当生态水泥用于钢筋混凝土结构时，预计会加速钢筋的腐蚀。氯化物可以在生产过程中去除，但成本较高。已生产两种类型的生态水泥：高氯型（I 型）和低氯型（II 型）。本文研究了嵌入含有两种类型生态水泥的砂浆中的钢筋的腐蚀行为，这些砂浆在干湿循环下固化并暴露于干湿循环中。通过半电池电位、极化电阻和交流阻抗测量来监测低碳钢棒的腐蚀。讨论了两种类型生态水泥相对于埋入钢筋腐蚀行为的相对性能，从结果中可以得出以下结论：（1）高氯型生态水泥砂浆中埋入钢筋的情况较多。 (2)碳化加速了两种生态水泥砂浆中埋入钢筋的腐蚀，但高氯型的腐蚀效果比低氯型的要高。 (3) 电测量在监测水泥砂浆中埋入钢筋的腐蚀方面取得了良好的效果。(4) 在两种类型的生态水泥中，埋入钢筋腐蚀的程度和严重程度取决于水水泥比，水灰比越高，腐蚀越严重。