La Miel, Colombia

Located in the hostile jungles of Colombia, La Miel is one of the largest RCC dams ever built. Its challenges were unique and difficult to overcome. Rotec engineered a Long Line Conveyor System rising over 100 m in elevation on mountainsides sloping 60 degrees where the rock was shaky and access nonexistent.

The Rotec Tower Crane works the job as the Rotec conveyor line, Towerbelt and Crawler Placer deliver the RCC

Location: Colombia, S.A.

Time: 2000

Contractor: Odebrecht

RCC Volume: 1,600,000 m³

Rotec Equipment Used: Long line 30″ Conveyors, Towerbelts, Tower Crane & Crawler Placer

Max. Size Aggregate: 6″

Best Day: 7,141 m³

Best Hour: 382m³/hr

Three Gorges Dam, China

After over 70 years of planning, designing, and debating, the project finally began in 1993. Since then, it’s been full speed ahead. The dam is located on the Yangtze River near the Village of Sandouping, Yichang, Hubei Province.

The structure itself is a gravity type dam with 13 power generators on each side of the spillway for a total installed capacity of 18.2 million kW. When completed the dam will have a crest height of 185 m and a crest length of 3,035 m. In addition to the dam structure, there will be two 5-stage ship locks and a single ship lift. One major challenge for the builder is to supply a huge volume of concrete, and to place it accurately and quickly.

After years of coordination, meetings, and project visits, Rotec proposed a conveyor system that would deliver concrete from three main batch plant areas directly to the active pour locations on the dam. The final conveyor system that was accepted and is in place today includes nine telescopic metering conveyors, six long line feed conveyors, and four Tower Crane/Towerbelts. All are controlled with three state-of-the-art computer control systems.

An epic undertaking to say the least. Rotec Towerbelts work on the biggest project in the world.

Location:
Yichang, Hubei Province
Peoples Republic of China

Time: 1993-2006

Contractor: CTGPC

Concrete Volume: 27,150,000 m³

Max. Size Aggregate: 6″

Rotec Equipment Used: Towerbelts and Tower Cranes, Creter Crane
CC-200, Long line 30″ Conveyors, 48″ Metering System, Augermax
& Super Swinger SS-75

Xiaolangdi Dam, China

It’s more than just a dam. Situated on the Yellow River 40km north of Luohang, the Xiaolangdi Multipurpose Project resulted in more than just a dam. In addition to providing flood protection to the 100 million local inhabitants downstream of the dam, the project also provided power generating capacity, irrigation control, water supply, and siltation control for the region.

The challenge to the contractors on this project was to overcome the difficult and complex nature of the concrete pours. Specifically, the massive intake towers (the largest in the world at 120 m tall!) and outlet tunnels all featured rebar dense pours with tight form work, making it nearly impossible to deliver concrete with traditional bucketing methods.

In order to meet the aggressive schedule of the project, three Rotec Tower Crane/Towerbelt Systems were selected. The Towerbelt systems, fed by Rotec Long Line Conveyors directly from the batch plants, provided large coverage areas and the means to accurately and safely place concrete in tight quarters at high placement rates. When not making concrete pours, the Rotec Tower Cranes did dual duty and functioned as high capacity lifting cranes.

Other features of this project included a rockfill dam, 10 intake towers, 9 flood and sediment tunnels, 6 power tunnels, and 1 underground powerhouse. The powerhouse features 1800 mW of power generation capacity from six 300 mW turbine/generator units.

Two Rotec Towerbelt Systems placing concrete at Xiaolangdi Dam, which contains the largest intake towers in the world

Location: Henan Province,
Peoples Republic of China

Time: 1994-1999

Contractor: CGIC

Concrete Volume: 50,000,000 m³

Max. Size Aggregate: 6″

Rotec Equipment Used: Towerbelts and Tower Crane, Creter Crane CC-200, Hi-Boy haulers

Caruachi, Venezuela

The Caruachi Hydroelectric Project is the newest large facility to be built on the lower reaches of the Coroní River in Bolivar State, Venezuela. Other notable power producing plants include the Guri Project. The purpose of this latest hydro project, along with its predecessors, is to harness the Coroní River by converting its power into electricity thereby allowing a larger percentage of Venezuela’s oil production to be exported.

The civil works of this project features the following:

  • 360 m long, 55 m tall gravity dam with intregal powerhouse and intakes
  • A 900 m long 50 m tall right abutment rockfill closure dam
  • A 4200 m long, 45 m tall left abutment earth and rockfill closure dam.

The powerhouse will have a capacity of 2160 MW (from twelve 180MW turbines). However, the integration of the powerhouse with the main dam dramatically increased the complexity of the construction requirements. It became necessary to place concrete at high rates in tight quarters. Additionally, the coverage area required was extremely large because of the main structure’s length. To overcome these obstacles, the contractor decided to mount our TC2400 Tower Crane/Towerbelts on traveler bases that could run the length of the dam and place concrete at any point on the structure.

Rotec Towerbelts and Creter Crane 200s dominate the concrete placement at Caruachi. The Rotec equipment is the perfect solution for precision placement in high rebar.

Location: Coroni River Bolivar State, Venezuela

Time: 1998 – 2006

Contractor: Dravica

Concrete Volume: N/A

Rotec Equipment Used: Tower Crane/Towerbelt systems, Creter Crane, Auger Max, Hog Dog haulers

Huites Dam, Mexico

Built on the Fuerte River near the Bay of California in the northwestern part of Mexico, the primary function of Huites dam is flood control, but it also vastly increases irrigation in the region while generating 426 MW of power.

The hybrid gravity and arch dam is 160 m tall with a crest length of 428 m. It was built by a consortium of three Mexican firms and a Brazilian company, called Consorcio Mexicano Constructor de Huites SA de CV, or CMCH. High production concrete placement was critical to meeting the tight schedule and bringing the powerhouse on line to produce revenue. The consortium considered using conventional bucket delivery systems – cranes on a trestle or cableways. The tight job site conditions and the height of the dam made it very difficult to reach the high production rate required. In the end, Rotec’s All-Conveyor System, that moved concrete directly from batch plant to final point of placement, proved to be unbeatable.

Each of the three batch plants produced up to 250 m³/hr; two were situated on the left bank and one on the right. From each batch plant, Rotec conveyors transported concrete to Rotec Towerbelts that were then used to place the concrete. The delivery system was extremely fast and reliable…concrete from mix plant to final placement in 30 seconds!

Three complete Towerbelt systems deliver concrete straight from the batch plant.

Location: Mexico

Time: 1992-1995

Contractor: CMCH

Concrete Volume: 2,840,000 m³

Rotec Equipment Used: Long line 30″ conveyors & Towerbelts

Max. Size Aggregate: 6″

Best Day: 13,300 m³

Best Month: 250,000 m³ (8.8% of total volume)

Woodrow Wilson Bridge Project

Rotec Industries has just premiered its new Shuttle Barge Delivery System on the Woodrow Wilson Bridge Project. The system is designed to transport concrete from a land based mixing plant directly to large bridge pier footings currently under construction on the Potomac River near Washingtion D.C. The system consists of both land and barge based large capacity holding hoppers (125 cubic yard) and high speed conveyor systems designed to move concrete quickly from mix plant to barge to final placement (tremie concrete and bridge piers, initially). High speed moving of concrete between systems is critical to maintain concrete quality from plant to placement. Average time to move concrete to final placement?. . . . about 45 minutes. This Rotec concrete delivery system saves the bridge contractor $$ by reducing the number of barges and tug boats used.

Rotec's Shuttle Barge carrying 100 cubic yards of concrete out to the pour on the Potomac.

LOCATION: Virginia – Maryland, USA

TIME: July 2001-2006

CONTRACTOR: Tidewater – Kiewit -Clark (TKC)

CONCRETE VOLUME: 200,000yd³

ROTEC EQUIPMENT USED: Rotec Port-O-Belt Conveyors, 48″ Land System, Shuttle Barge Systems, Creter Crane 200 Barge System

Wacker Drive, Chicago

Rotec Industries, Inc. provided concrete placing equipment and services for Walsh Construction on the Wacker Drive Restoration Project in downtown Chicago. The new Wacker Drive viaducts are cast-in-place, post-tensioned, super high-performance concrete slab structures, designed to provide 100 years of service under Chicago’s widespread use of de-icing salts. For this pour, the Rotec placing system consisted of two conveyor lines on monorails that traveled out to the pour, and two SS105 Super Swingers (see inset) that were used to reach areas where the conveyor lines could not. Peak placing rates approached 300 yd³/hr., making it possible for the 2200 yd³ pour to be completed in 9 hrs. That was one hour ahead of the targeted schedule!

A Super Swinger 105 setting up at a pour location outside the reach of the Beltcrete conveyor lines.

The concrete, supplied by Prairie Ready Mix, had a complex mix design which required strict adherence to design specifications. Every truckload was tested for air entrainment and slump. Two major brand-name concrete pumps were used, but were quickly rejected because air entrainment was affected by the pressure at which pumps must operate. On the other hand, Rotec conveyors did not affect air entrainment or slump, because concrete riding on a belt always remains at atmospheric pressure.

Making a success of this project was no easy task considering the tough concrete mix, the peculiar shape of the viaduct (see photo), the simultaneous pours from four different locations, and the downtown Chicago traffic. Rotec’s high-speed conveyor systems have been used advantageously on numerous high-profile projects, allowing contractors to substantially reduce placement times, saving as much as $6,000/hr.

Rotec/Beltcrete conveyor lines set up and beginning to place concrete on Chicago's Wacker Drive Restoration Project.

Location: Chicago, IL.

Time: Summer, 2002

Contractor: Walsh

Concrete Volume: N/A

Rotec Equipment Used: Two Beltcrete Conveyor Systems and two Super Swingers (truck mounted conveyors)

Penn Forest Dam

The original Penn Forest Dam was completed in 1958 to provide the City of Bethlehem, Pennsylvania, with a water supply. However, upon first filling in 1960, the dam failed and a large 5 m diameter sinkhole developed on the upstream slope near the right abutment.

After 34 years of continuous monitoring and efforts to repair the growing sinkhole, the structural integrity began to decline rapidly and a catastrophic failure became a serious potential. Nine long-term repair options were initially considered, reduced to three, and then finally to one. The final solution was to construct a roller compacted concrete (RCC) replacement dam on a fast-tracked design-build plan. ROTEC was called in by the owner and designer/construction manager in the early stages of the replacement dam development to propose a feasible All-Conveyor RCC Delivery System – from plant to final placement.

Due to the doglegged design of the dam, Rotec proposed and later supplied 2 independent all-conveyor systems. The system of tripper and plow conveyors could be traveled and controlled to deposit RCC precisely where needed, anywhere on either length of the dogleg. To the delight of the owner, the RCC replacement dam construction project was a huge success and an eminent disaster was safely avoided!

Two Rotec conveyor systems with "plows" place RCC on this project.

Location: Bethlehem, PA.

Time: 1996

Owner: City of Bethlehem

Designer: Gannett Fleming Inc.

Contractor: Conti Enterprises, Inc.

RCC Volume: 380,000yd³

Dam Length: 1,960 ft

Rotec Equipment Used: 24″ Port-O-Belt Conveyors, Tripper & Discharge Plow