Construction of Iran's first large RCC dam

The Jahgin RCC dam, in Hormozgan Province, Southern Iran, some 400 km east of Bandar Abbas, was constructed in the most difficult environments in the world. The conditions at the Jahgin site are extremely challenging. There is a lack of water, the nearest source being 60 km away, and throughout the year the temperatures are high. The sandstone aggregates were obtained from a gravel borrow pit in the reservoir area. An aggregate plant was designed to crush the oversize material and four sizes of aggregate were used. Unfortunately the RCC mixes containing the Esfahan ground slag and the Jiroft copper slag had a less satisfactory performance and as there were problems with the milling of the materials, neither was considered further. Admixtures from five or six different suppliers were tested during the supplementary program. The results of the Stage-1 program showed that there were essentially only two pozzolans which were satisfactory for the RCC at Jahgin, both in terms of their strength development and also in terms of practicality.