Ciber participates in first-of-its-kind experiment in Brazil with the hydroelectric plant at Chapecó Falls
The Latin American leader in production and sales of a complete line of products used for paving and road maintenance, Ciber Equipamentos Rodoviários, located in Porto Alegre (RS), is taking part in a first-of-its-kind experiment in Brazil, operating a UAB 18E gravimetric asphalt plant for the hydroelectric plant being built on the Chapecó Falls in the state of Santa Catarina. The project, which is being executed by the contractor Camargo Corrêa, is using methodology already in use in Europe, in which the impermeable nucleus of the rockfill is built in asphalt instead of using the conventional method with clay or RCC (roller compacted concrete).
The technology consists of three compacted asphalt layers of 20 cm each per day. “The project’s specifications demanded the use of this type of high performance plant, which produces a much superior asphalt mix. To this end, the final dosing system, which makes it possible to produce any type of mixture, such as SMA, mixes with fibers and rubber-asphalt, was a determining factor in our decision to buy this kind of plant,” explained sales director Clauci Mortari.
The project in question requires a large quantity of HMAC, to the order of 6.6% of asphalt mix. The high HMAC percentage is due to the need to reduce voids in the mix. For this reason, the mix uses a large quantity of fine materials, both the rock fines that are recovered by the bag filter and returned to the dosing and mixing process and the dolomite limestone coming from a bin that is external to the plant and that also undergoes a dosing and mixing process. The quantity of fines and fillers in the asphalt mix is very high because of the requirement for very few voids in the asphalt mix. The filler used – dolomite limestone – was chosen because of the adhesivity needed in the asphalt mix and the heavy specific weight of this limestone, which can reach 2.4 t/m3.
The plant, which is produced by Ciber, is stationary and meets the demands for production of mixes from permanent locations and is ideal for contractors that have high demands for quality control, with product specifications. “This project requires a production rate of 300t/day and one of the project’s requirements is for a minimal quantity of voids in the asphalt mix, due to the strict requirement for impermeabilization of the dam’s rockfill nucleus, in order to achieve efficient impermeabilization,” added the director.
Ciber has been expanding its sale of gravimetric plants and has units in operation in Colombia, Bolivia and in Brazil, in the states of São Paulo and Santa Catarina. The Chapecó Falls project will generate enough capacity to meet 25% of Santa Catarina’s energy consumption or 18% of Rio Grande do Sul's, which corresponds to 855MW.