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    What is RCC construction?
    RCC structures are normally heavier than those made of steel, wood, or glass. Generally, RCC buildings require a lot of labour and site or workspace to fix because they require massive formwork, centring, and shuttering. It takes time for RCC to reach its maximum strength. Thus, it cannot be use right away after construction.
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    Roller-compacted concrete - Wikipedia

    Roller-compacted concrete (RCC) or rolled concrete (rollcrete) is a special blend of concrete that has essentially the same ingredients as conventional concrete but in different ratios, and increasingly with partial substitution of fly ash for portland cement. The partial substitution of fly ash for Portland Cement is an important aspect of RCC dam construction because the heat generated by fly ash hydration is significantly less than the heat generated by portlan…

    Roller-compacted concrete (RCC) or rolled concrete (rollcrete) is a special blend of concrete that has essentially the same ingredients as conventional concrete but in different ratios, and increasingly with partial substitution of fly ash for portland cement. The partial substitution of fly ash for Portland Cement is an important aspect of RCC dam construction because the heat generated by fly ash hydration is significantly less than the heat generated by portland cement hydration. This in turn reduces the thermal loads on the concrete and reduces the potential for thermal cracking to occur. RCC is a mix of cement/fly ash, water, sand, aggregate and common additives, but contains much less water. The produced mix is drier and essentially has no slump. RCC is placed in a manner similar to road paving; the material is delivered by dump trucks or conveyors, spread by small bulldozers or specially modified asphalt pavers, and then compacted by vibratory rollers.

    In dam construction, roller-compacted concrete began its initial development with the construction of the Alpe Gera Dam near Sondrio in North Italy between 1961 and 1964. Concrete was …

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    Wikipedia

    For dam applications, RCC sections are built lift-by-lift in successive horizontal layers resulting in a downstream slope that resembles a concrete staircase. Once a layer is placed, it can immediately support the earth-moving equipment to place the next layer. After RCC is deposited on the lift surface, small dozers typically spread it in one-foot-thick (about 30 cm) layers.

    The first RCC dam built in the United States was the Willow Creek Dam on Willow Creek, a tributary in Oregon of the Columbia River. It was constructed by the US Army Corps of Engineers between November 1981 and February 1983. Construction proceeded well, within a fast schedule and under budget (estimated US$50 million, actual US$35 million). On initial filling though, it was found that the leakage between the compacted layers within the dam body was unusually high. This condition was treated by traditional remedial grouting at a further cost of US$2 million, which initially reduced the leakage by nearly 75%; over the years, seepage has since decreased to less than 10% of its initial flow. Concern over the dam's long-term safety has continued however, although only indirectly related to its RCC construction. Within a few years of construction, problems were noted with stratification of the reservoir water, caused by upstream pollution and anoxic decomposition, which produced hydrogen sulfide gas. Concerns were expressed that this could in turn give rise to sulfuric acid, and thus accelerate damage to the concrete. The controversy itself, as well as its handling, continued for some years. In 2004 an aeration plant was installed to address the root cause in the reservoir, as had been suggested 18 years earlier.

    In the quarter century following the construction of the Willow Creek Dam, considerable research and experimentation yielded many improvements in concrete mix designs, dam designs and construction methods for roller-compacted concrete dams. By 2008, about 350 RCC dams existed worldwide. As of 2018, the highest dam of this type was the Gilgel Gibe III Dam in Ethiopia, at 250 m (820 ft), with the Pakistani Diamer-Bhasha Dam under construction at 272 m (892 ft).

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    • Abdo, Fares (2008-11-01). "Roller-Compacted-Concrete Dams: Design and Construction Trends". Hydro Review. Retrieved 2017-04-16.
    • Berga, Luis (2003). Roller Compacted Concrete Dams. Taylor & Francis. ISBN 978-90-5809-564-0.

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