Table 1. Typical Features of the two Main Current Tendencies in the Design of RCC Dams

All RCC dams Compound RCC dams
Concrete consistency Low VeBe times (10-15 secs) Medium & high VeBe times (>25 secs)
Water/cement ratio 0.50 – 0.70 0.80 – 1.20
Use of pozzolanic material and mix retardation >50% of total cement content and highly retarded mix <25% of total cement content and mix not specially retarded
Construction of lift joints Surface paste that is brought up during compaction of the RCC Improved by bedding mixes that are manufactured separately
Water-tightness Impervious and monolithic RCC matrix and lift joints Upstream waterproof membrane
Interfaces Grout-enriched RCC CVC, pre-cast panels or grout enriched RCC
Possible speed of construction Very high (average can be more than 100,000m3/month) High (but average less than 65,000m3/month) + membrane
Performance Very good if properly designed and constructed Very good if properly designed and constructed
Cost for each particular site (see section 3) Can be 25% to 30% less than CVC dams Between 5% and 20% more than the all-RCC dam