7.0.1 Design of temperature control shall be conducted for high-and medium RCC dams and it may follow the stipulation in SL 319 and SL 282. For low dams, the design of temperature and crack control may use a simplified method or refer to similar projects.
7.0.2 In order to conduct the temperature control design of RCC dams, the allowable foundation temperature difference, temperature difference between two adjacent lifts of concrete, temperature difference between exterior and interior concrete and the peak temperature inside the dam shall be studied, and then the criteria of temperature control and crack prevention measures shall be proposed.In the meantime, attention shall be paid to the thermal insulation design for the surface of RCC during cold wave period or winter.n cold and severe cold areas, the requirements of temperature control design should be proposed every ten days.For high RCC gravity dams and high- and medium RCC arch dams, the temperature control criteria and crack prevention measures should be determined through FEM simulation analysis.
7.0.3 The following measures shall be taken to control temperature rise of concrete due to hydration heat without vulnerating the strength and durability of RCC:1 Determining the appropriate amount of admixture.
2 Using cement with low hydration heat.
3 Using high efficient water reducing agent.
7.0.4 Suitable materials shall be used to improve the performances of RCC. And the management and techniques of RCC construction shall be improved to increase the crack resistance of RCC.Indices re-garding crack resistance of RCC shall be proposed in the design of temperature control.
7.0.5 The thickness of compacted layer, lift height and the method of compaction shall be determined according to project features,tem-perature control, construction conditions, weather conditions,construction schedule, etc. The time interval between lifts should be determined through temperature control analysis.
7.0.6 Concrete placement shall be properly scheduled. RCC should be placed in cold seasons.
7.0.7 The following temperature control measures may be taken:I Spraying water onto coarse aggregates, stockpiling aggregates in large piles, taking aggregates via the gallery beneath stockpile, using mat shelter.
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