To build the roller-compacted-concrete (RCC) Cuchillo Negro Dam, PCL Civil Constructors Inc. used a conveyor system that delivered the RCC mix from the mixing plant to the dam site. The 1,500 feet of conveyors with a maximum belt capacity of almost 9 cubic yards per minute delivered the RCC mix to the jobsite without interruption or downtime. PCL placed an average of 158 cubic yards an hour during the 62-day pour.
PCL leased a conveyor system that included feeder and radial components. A 24-inch by 400-foot feeder conveyor was charged by PCL's pug mill mixing plant. This line fed a 600-foot conveyor, which went over a hill, and, in turn, fed a series of four or five 100-foot conveyors, ending at the rising level of RCC at the right abutment. Here, linked to the over-the-hill conveyor by a 100-foot conveyor or two 50-foot conveyors, were two radial conveyors. These two 65-foot-reach, telescoping devices swing through an arc to deposit the mix through elephant trunk discharge hoses. The two radial conveyors were supported on the crest by a pair of corrugated metal pipe (CMP) vertical culverts. The CMPs were deeply embedded into the RCC of the crest and the base shafts from each conveyor were inserted into them. When the crest level approached the tops of the culverts, the base shafts were withdrawn. Then the two conveyors were relocated into another pair of culverts embedded into the RCC, protruding up another 20 feet or so.
