Corrosion Risk of Steel used as reinforcement in a Reinforced Concrete within Kabupaten Bireuen: Analysis of groundwater content used as a concrete mixture

Corrosion is one of the main causes of reinforced concrete (RC) failures. The use of ground water which does not meet the standard as mixed water triggers degradation of concrete and corrosion. The main focus of this research is to examine the corrosion risk affected by groundwater content used as a concrete mixture. An experimental study was carried out on conventional reinforce concrete beam (RCB) with 2,5 cm concrete cover and 10 mm of steel reinforcement diameter. The groundwater used as a concrete mixture selected from three locations in Kabupaten Bireuen. The selected locations are Gampong Lhok Awe (A), Gampong Krueng Juli Timu (B) and Gampong Paya (C). The specimens were set in a wet-dry cycle and immersed in an artificial seawater of 3.5% NaCl solution. The measurement was performed by using half-cell potential mapping technique. The experimental results show that the corrosion risk to RCB specimens were at intermediate to severe level, just in five week of wet-dry cycle immersed. In addition, the corrosion risk of RCB A were at severe corrotion level, while RCB B at high (>90% risk of corrotion) and RCB A still at intermediate levels. If expressed as a percentage, the potential values of RCB C and B are 34.9% and 16.0% more negative than RCB A. Laboratory test results of groundwater chemical content show that corrosion risk of RCB spesimens will be strongly influenced, especially by chloride content. Chloride content at Gampong Paya is far above the standard content set in the ASTM C 1602 M-04 standard. While at two other locations Gampong Lhok Awe and Gampong Krueng Juli Timu, the chloride content was below the standard limit. Differences in the amount of chloride contained in groundwater causes the level of risk of corrosion imposed also different