Extreme paving at an incline of 31°.

The hydropower plant project in the Chinese province of Henan was extreme in every sense of the word: The colossal amount of 3 million cubic metres of water was to turn the turbines of a hydropower plant, generating a total output of 1,200 MW of electric power. The plant’s water reservoirs, one located in the valley and one in the mountains, have retaining walls with 31-degree slopes. The main reservoir in the mountains was to be lined with an asphalt sealing layer. The challenge of carrying out the job was taken on by a modified paver Super 1800-2. In close co-operation with the client, Wirtgen China and Joseph Vögele AG worked at getting the paver “in shape” for the enormous loads it would be exposed to on the steep slope.

Following modification into a slope paver, the Super 1800-2 was sent to Henan, some 750 km from Beijing, to complete the demanding job. The Baoquan pumped-storage project posed an extraordinary challenge even for the booming Chinese construction industry. It was also an important investment in terms of ensuring the local power supply in the province of Henan, which is the most heavily populated province of this huge country, being home to 96 million people.

The water reservoir was sealed with an asphalt lining. A total surface of 166,000 m² needed to be paved on the walls of the reservoir alone – in two layers of 10 cm thickness each. The fairly high bitumen content in the binder and surface course layers was necessary to ensure waterproofing. The paver worked its way from the bottom upwards when paving the 80 m long strips, assisted and secured by a rope winch.

The Super 1800-2 slope paver was equipped with an extending screed type AB 500-2 TP2, paving the individual strips at widths varying between 2.50 m and 4.00 m. On the 31-degree slope, the Vögele machine was operating at an advance speed of 1.50 m per minute. One small roller was sufficient for carrying out final compaction. In the Baoquan hydropower plant project, an articulated tandem roller HD 13 from Hamm was used, which was also secured during operation by a rope winch.

Job site: Main reservoir of the Baoquan hydropower plant, Henan Province, China
Project size: 166,000 m²
Slope gradient: 31°
Paving width: 2.50 to 4.00 m
Paving speed: 1.5 m/min
Layer structure: 10 cm each binder course and surface course