Slipforms for hydropower projects
POWER & RENEWABLE ENERGY

Slipforms for hydropower projects

HCC opted for slipforms for the concreting of a 115-m-deep surge shaft for the Punatsangchhu hydropower project Stage I, a 1,200-mw, run-of-the-river project in Western Bhutan.

“We opted for slip-forming because it enables continuous, non-interrupted, cast-in-place jointless concrete structures that have superior performance characteristics compared to piece-wise construction using discrete form elements,” says S D Jeur, Senior Vice-President, Projects, HCC.

Slipforms with a three-layered platform structure were used. The entire formwork structure was built in-house. The top platform was used to erect the reinforcement concrete, the middle platform was used for general movement, and the bottom one was used to provide the finishing to the concrete surface.

Slipforms have to be in a continuous motion so that the concrete does not stick to them. The speed of this formwork depends on several factors like the weather condition, the amount of concrete poured at a time and the size of the structure. As the slipform can move (slipping rate, usually between 5 and 30 cm/hour) whenever the concrete can carry the load of its weight in the lowest parts of form sheet, the likely concrete setting time was determined based on the weather conditions (temperature, humidity, etc), cement ratio, type of cement, slump and admixtures.

Usually, the slipform structure rises up with the daily progress of 0.75 m/day in standard conditions. However, at Punatsangchhu-I HEP, the daily progress harnessed from slipform was at an average of 1 m/day. The concrete lining thickness varied from 850 mm at the top, 1,200 mm in the middle and 1,500 mm at the bottom. Concrete was poured into the forms in layers of about 200 mm.

CHARU BAHRI

HCC opted for slipforms for the concreting of a 115-m-deep surge shaft for the Punatsangchhu hydropower project Stage I, a 1,200-mw, run-of-the-river project in Western Bhutan. “We opted for slip-forming because it enables continuous, non-interrupted, cast-in-place jointless concrete structures that have superior performance characteristics compared to piece-wise construction using discrete form elements,” says S D Jeur, Senior Vice-President, Projects, HCC. Slipforms with a three-layered platform structure were used. The entire formwork structure was built in-house. The top platform was used to erect the reinforcement concrete, the middle platform was used for general movement, and the bottom one was used to provide the finishing to the concrete surface. Slipforms have to be in a continuous motion so that the concrete does not stick to them. The speed of this formwork depends on several factors like the weather condition, the amount of concrete poured at a time and the size of the structure. As the slipform can move (slipping rate, usually between 5 and 30 cm/hour) whenever the concrete can carry the load of its weight in the lowest parts of form sheet, the likely concrete setting time was determined based on the weather conditions (temperature, humidity, etc), cement ratio, type of cement, slump and admixtures. Usually, the slipform structure rises up with the daily progress of 0.75 m/day in standard conditions. However, at Punatsangchhu-I HEP, the daily progress harnessed from slipform was at an average of 1 m/day. The concrete lining thickness varied from 850 mm at the top, 1,200 mm in the middle and 1,500 mm at the bottom. Concrete was poured into the forms in layers of about 200 mm. CHARU BAHRI

Next Story
Infrastructure Urban

India Spent Rs 1.5 Tn on Smart Cities in Past 10 Years

The Indian government launched the Smart Cities Mission on June 15, 2015, with the goal of transforming urban infrastructure across the country. As of April 11, 2025, ten years since its inception, over Rs 1.5 trillion has been spent on 7,504 completed projects, representing 94 per cent of the total planned projects valued at more than Rs 1.64 trillion. An additional Rs 131.42 billion worth of projects are currently under implementation. According to data from SBI Research, 92 per cent of the funds were utilised across 21 major states, with Uttar Pradesh, Tamil Nadu, and Maharashtra together ..

Next Story
Infrastructure Urban

DDA Approves Rs 87.2 Billion Budget for 2025-26

The Delhi Development Authority (DDA) has approved a budget of Rs 87.2 billion for the financial year 2025-26, with a strong emphasis on civic infrastructure development, green space rejuvenation, housing, and sports facilities, according to an official statement. Chaired by Lieutenant Governor V.K. Saxena, the budget meeting highlighted several large-scale projects, including the revitalisation of the Yamuna floodplain, creation of expansive parks, and upgraded civic amenities. Out of the total outlay, Rs 41.4 billion has been earmarked for capital expenditure, covering new roads, infrastruc..

Next Story
Infrastructure Energy

Vi Taps Cisco to Power Next-Gen Network

Telecom operator Vodafone Idea (Vi) has joined hands with US-based tech major Cisco Systems to revamp its transport network infrastructure across India. The strategic partnership aims to enhance network performance, scalability, and user experience for both retail and enterprise customers. As part of the agreement, Vi will deploy Cisco’s advanced Multiprotocol Label Switching (MPLS) technology to create a high-capacity, software-driven transport network. This will significantly improve the telecom player’s ability to manage surging data traffic and support data-heavy digital services such..

Advertisement

Advertisement

Subscribe to Our Newsletter

Get daily newsletters around different themes from Construction world.

STAY CONNECTED

Advertisement

Advertisement

Advertisement

Advertisement

Talk to us?