A concrete structure reinforced with reinforcing bars formed an important part on current infrastructures. The high compressive strength of concrete combined with a high tensile strength of steel give an ideal composite material which offer a wide range of application within civil engineering structures. The aim of this research is to observe the corrosion process on reinforcing bars of reinforced concrete structure which is made by local aggregates which have the compressive strength ranged from 25 to 30 MPa, with different quarry in the area of Special Region of Yogyakarta. The ASTM G-109 and Florida Test of Method FM 5-522 are chosen to conduct this research. The test was conducted 45 to 60 days with following data to be taken: water salinity (pH), voltage reading relative difference, reinforcing bar’s mass loss. The data processed to obtain corrosion current density (CCD) and corrosion rate (CR). The results as follow : (1) the voltage difference’s reading on each specimens attempt to be similar, (2) the CCD on each specimens behave differently with relative differences of 1,68%, (3) the CR on each specimens behave differently with relative differences of 0,66%, (3) the specimens behave similarly regardless the differences between two of them.

钢筋混凝土结构是当前基础设施的重要组成部分。混凝土的高抗压强度与钢的高抗拉强度相结合，是一种理想的复合材料，可在土木工程结构中提供广泛的应用。本研究的目的是观察日惹特区地区不同采石场采用抗压强度为 25 至 30 MPa 的局部骨料制成的钢筋混凝土结构钢筋的腐蚀过程。选择 ASTM G-109 和佛罗里达测试方法 FM 5-522 来进行这项研究。测试进行了 45 至 60 天，需要获取以下数据：水盐度 (pH)、电压读数相对差、钢筋的质量损失。处理数据以获得腐蚀电流密度（CCD）和腐蚀速率（CR）。结果如下：（1）每个样品上的电压差读数试图相似，（2）每个样品上的 CCD 表现不同，相对差异为 1.68%，（3）每个样品上的 CR 表现不同0,66% 的相对差异，(3) 无论两个样本之间的差异如何，样本的行为都相似。