For many centuries, dams have played an essential role to store water for different purposes, such as irrigation, water supply, hydroelectric power and flood control. Today agricultural irrigation and hydroelectric power, also known as hydropower generation, are by far the most common functions for dams. Sika supplies innovative solutions for the largest and technically complex dam and hydropower plant designs.
Planned Hydro Capacity by Region2
Systems Plus Knowhow
Dams are structures that present particular challenges and complexities. Sika’s specialists understand these and provide advice with problem solving solutions to safely and securely meet all necessary design, construction and in-service performance requirements, for both new build and renovation projects. Sika solutions make a positive contribution to the overall performance of all types of hydraulic structures, while also potentially reducing construction and operating costs.
Sika is your single source of integrated, fully compatible solutions for dams and hydropower plants throughout their life cycle in the following areas:
Admixtures for concrete and shotcrete
Concrete protection and repair
Sealing, bonding and steel protection
Technical support and onsite services
1. Main Dam
Dams can be exposed to a wide range of stresses and strains, starting internally with the thermal stress resulting from mass concrete construction, the high static and dynamic loadings, the hydrostatic water pressure in construction and in service, plus additional seismic forces in many regions. The construction materials have an essential role in being able to resist all of these forces. Conventional concrete dams are obviously stronger and more stable than earth dams, but at the same time they are also much more expensive. Roller-compacted concrete (RCC) technology uses concrete with “no-slump consistency” that usually provides the most cost effective construction material for dam building.
Requirements for Successful Dam Construction
- Highly durable concrete with reduced permeability and excellent performance
- Extended workability and increased setting time in order to complete the placing procedures (essential for RCC)
- Correctly engineered and practical sealing solutions for each and every type of joint in the structure
- Highly durable grouting products
- Steel protection solutions to reduce corrosion in CVC structures
Sika Solutions for Conventional (CVC) and Roller-Compacted Concrete (RCC) Dams
Water reduction and plasticizing with Sika? Plastiment? (recommended for RCC dams) and Sika Plastocrete? technology, to increase setting time and enhance workability of the concrete.
High range water reduction and plasticizing with Sikament? technology (recommended for CVC dams), to provide enhanced strength development and controlled workability.
SikaControl? AER to increase the frost and freeze/thaw resistance for dams exposed to extreme climatic conditions.
Sika? Antisol? for controlled curing of the concrete to significantly enhance durability.
Sika? FerroGard? corrosion inhibitor to prevent the corrosion of steel reinforcement.
Sika Waterbar? flexible PVC waterstops for the integral sealing of movement and construction joints in watertight structures. Sika Waterbar? products are available in a wide range of different types, shapes and sizes to suit different types of structures and joint sealing applications.
Sika Solutions for Earth Dams
Water reduction and plasticizing with Sika? Plastiment? (for CFRD dams) and Sika Plastocrete? technology, to increase setting time and enhance concrete workability.
Sika? ViscoCrete? technology for highly workable shotcrete with improved rheology and pumpability.
SikaGrout? series for grouting in and around foundations, plus to fill voids, holes and cavities in the hardened concrete, or for embedding drainage pipes and other penetrations and elements.
2. Slope Stabilization
One of the many applications of shotcrete is slope support. Slopes are generally designed so that the rock mass can support itself, but frequently this requires additional support. Shotcrete is also ideal for slope stabilization due to its ease of adaptation to site profiles and requirements, its capacity to stick to the rock and its high early strength and resistance. As shotcrete is spray-applied, the material is compacted against the surface to also fill any cracks and prevent any loose materials from falling. Shotcrete therefore provides a protective coating over the slope’s surface and also helps to consolidate and stabilize or ‘anchor’ the surface. In addition, drainage systems such as Sika FlexoDrain can be fixed into and onto the slope with shotcrete, which is important for ensuring future stability.
Sika Solutions for Slope Stabilization
Specialist shotcrete products, systems and equipment solutions using: Sika? Sigunit?, Sika? ViscoCrete?, SikaTard?, SikaPump?, SikaTell?, SikaFiber?, SikaFume?, Sika? Aliva?, and Sika? Shot.
Sika? Injection technology using flexible polyurethane and acrylic resin based injection systems.
3. Spillway and Intake Structures
In a hydropower plant, the intake structures and the spillways are some of the associated secondary structures that are required along with the main dam itself. These structures are usually reinforced concrete structures which are used to collect water from the reservoir. The type of intake structure generally depends on its location and function as well as the other associated hydraulic structures that make up the plant, such as the concrete towers and artificial banks.
Sika Solutions for Spillways and Intake Structures
For construction of the associated reinforced concrete structures, Sika produces a large variety of concrete admixtures and ancillary concreting products. This include:
Plasticizers, high range superplasticizers for improved workability, strength and durability, set and hardening accelerators for a faster production process, plus mold release agents for easy de-molding of formwork in-situ.
Sika Fiber? can also be used; these special fibers are incorporated in the concrete mix to improve the performance and durability of concrete and mortar. They can specifically increase energy absorption and fire resistance, whilst reducing shrinkage cracking, fracture formation and crack-widths.
Sika? Antisol? curing compounds are also used to achieve higher durability as they protect horizontal concrete surfaces against excessive evaporation and promote full curing, especially at the surface.
Sika grouting technologies include systems with cementitious, epoxy and polyurethane resin based binders. Engineering grouts are designed to completely fill voids and transfer load directly within the concrete structure.
SikaGrout? and Sikadur? are ideal for filling both vertical and horizontal joints between structural elements as well as for sealing voids and areas of honeycombing, for example. ?
Protecting the surface of the dam and its associated structures prolongs the service life and can prevent expensive damage and outages, or the need for costly repairs. Protective concrete coating systems are also used to enhance and maintain the visual appearance, with Sika products and systems developed to suit all of the relevant water and hydropower industry regulations and service conditions.
The Sikagard? range includes penetrating hydrophobic impregnations, as well as both rigid and flexible protective coating systems, which are proven to protect concrete surfaces from the ingress of water and aggressive atmospheric influences.
SikaCor? and Sika? Permacor are high performance steel corrosion protection products and systems designed for use as internal linings for tanks and penstocks etc., as well as to protect externally exposed steelwork in all kinds of aggressive environments. ?
Elements such as precast concrete units must be structurally bonded together to provide a rigid bond between them that is able to directly transfer load. Sikadur? epoxy adhesives are widely used to very effectively bond concrete elements together in this way, including for segmental bridges and water retaining structures, where they also provide a secure watertight seal.
The Sikadur? products and systems also have many other concrete bonding and sealing applications, plus with excellent adhesion to many other materials, they can be used for rigid structural bonding on many different substrates.
4. Underground Work
Tunnels are usually required in dam building projects where the topographical conditions prevent simple open-channel construction. For example, water diversion tunnels are commonly required additional structures for large dam projects. When a dam is to be built, a tunnel is frequently bored first, in order to divert water away from the actual dam construction site itself and so that it essentially bypasses it.
The Sika product range for tunnels and below ground construction is absolutely extensive and the fruits of more than 100 years of specific experience, continuous improvement and innovation in tunneling. This huge product range comprises all the latest technologies to provide the best and most cost effective solutions for your projects.
Sika Solutions for Underground Work
Sika? ViscoCrete? Superplasticizers
Sika? ViscoFlow? Slump retainers
Sika? Stabilizer Viscosity control agents
SikaPump? Pumping aids
SikaPump? Start-1 Lubricant
SikaFume? Silica fume
SikaFiber? Micro and macro synthetic and steel fibers
SikaCare Equipment protection
Sika? ViscoCrete? Superplasticizers
SikaTard? Shotcrete retarders
SikaPump? Pumping agents
FlexoDrain Water drainage system
SikaFiber? Micro and macro synthetic and steel fibers
Sika? Aliva? Sprayed concrete machines
Sika? Shot Ready mixed gunite
Sikaplan? WT TPO based sheet waterproofing membrane systems
Sikaplan? WP PVC based membranes
Sika? WT/WP/Dilatec Preformed, bonded tapes for waterproof connections and terminations
Sika? Waterbars Joint waterproofing systems
SikaSwell? P Hydrophilic swelling profile for joint sealing
SikaFuko? Injectable hoses for joint sealing and secondary / back-up waterproofing
Sika? Injection Resins for post-applied waterproofing by injection
SikaFix? Fast reactive injection products that expand with or without contact with water, mainly injected using a two-component pump. The SikaFix? range is designed for immediate water-stopping under high water flow and hydrostatic pressure conditions.
Sika? Foam TBM Complete range of TBM soil conditioners and polymers
Sika? Stabilizers Special main drive and tail sealants
Sika? Set Accelerators for controlling the set of back-filling grouts
Sika? Retarder For retarding and stabilizing back-filling grouts
SikaGrout? Complete range of high-performance, cementitious grouting systems
Sikadur? Complete range of epoxy grouting systems
Icosit? KC Range Two-component, polyurethane resin grouts, especially designed for fixing rail tracks and heavy machinery to reduce vibration and noise transmission
SikaBond? R&B-100 High performance, two-component elastomer for fast and durable conveyor belt repairs
SikaBond? R&B-200 Structural adhesive with a short open time for bonding rubber materials
SikaBond? R&B-210 Structural adhesive with a long open time for bonding rubber materials ?
The main powerhouse hosts the turbines, generators and their necessary auxiliary equipment and the size of the structure obviously depends on the dam design and the types, dimensions, and number of generating units installed. The building is usually a large reinforced concrete structure having three distinct areas: the main powerhouse or generator room, the erection bay for transformer tanking and un-tanking, plus the service area, which generally includes the main control room, offices and other areas for auxiliary equipment.
Sika Solutions for Powerhouses
Powerhouse building structures are normally built with reinforced concrete. Sika provides the widest range of concrete admixtures and additives to help ensure that the concrete can meet the project requirements and various standards.
Typical admixtures include Sika? ViscoCrete?, SikaControl?, SikaRapid? and more.
Typical applications are water reducing admixtures, set controlling admixtures, workability improving admixtures, durability admixtures and essentials to improve the quality of concrete.
Floors in powerhouse need to be mechanically resistant because of the maintenance work or forklift traffic, sometimes there is oil on the floors. For these exposures, normally epoxy flooring is specific to protect the floors. For floor areas where there is strong vibration, polyurethane flooring is more proper. Sika is a global technology and market leader in durable seamless flooring technologies.
Typical systems for the above requirements are Sikafloor? MultiDur or Sikafloor? MultiFlex. ?
Sika is a roofing system solution provider that covers a wide range of applications and technologies to the latest standards. With over 50 years of history, our roofing solutions are renowned for their durability and premium qualifications.
Typical systems are Sarnafil? and Sikaplan? single ply membrane systems, and SikaBit? bituminous membrane systems.
6. Penstock and Gates
The dam penstocks are large pipes that control and convey pressurized water to the powerhouse turbines. These can be designed and positioned to run along at ground level, or below ground as a buried pipe, principally depending on the topography and geology of the site. There are two different layouts that are commonly designed and used, which are to have a separate penstock for each generating unit, or a larger penstock with branches into each of the generating units from close to the powerhouse. Penstocks themselves are usually made of steel, but plastic and concrete sections can also be used. Powerful gates and mechanical filters are essential to avoid any solid materials that may be picked-up, from entering and damaging the electromechanical generation equipment of the turbines.
Sika Solutions for Penstocks and Gates
Sika? Poxitar? F
This is an extremely mechanically and chemically resistant protective coating system for steel and concrete surfaces that is used extensively for the internal penstock linings and hydraulic gates all around the world. These reaction hardening materials are based on an epoxy-anthracene oil-combination and can be exposed to water immediately after application, which means they are also ideal for mechanical damage repairs and penstock maintenance with minimum downtime.
This is a large range of two component epoxy resin coating systems that are widely used for many different protective coating applications internally and externally on penstocks, in and around the dam powerhouse and on ancillary structures. These solvent-free, well proven materials provide a durable protective coating and can also be used on adjacent concrete surfaces to provide overall protection against mechanical wear and chemical exposure, as well as an impermeable barrier to water penetration.
For grouting of heavy machinery, equipment and base plate with subsequent
high resistance to dynamic loading, heavy impact and vibration, even under water, Sika supplies:
SikaGrout? range of high performance, cementitious grouting systems
Sikadur? range of epoxy grouting systems
7. Dam Repair
Ensuring dam safety allows to protect the people's lives and property and to foster the development of the society. However, existing dams can be vulnerable to severe hazards such as floods and earthquakes, and even small defects in dams can lead to significant damages due to service and environmental conditions. Concrete cracking is the deficiency most often reported. Other major problem areas are seepage, spalling and abrasion especially on spillways.
Since many of the existing dams today are operating beyond their normal 50-year service life and will have to continue to be operable, there is a great need for solutions concerning the repair and rehabilitation of these structures.
Typical Problems in Dams
- Cracks in the dam body
- Leakage in intake gate
- Leakage in draft tube
- Leakage in inspection gallery
- Abrasion of spillways
- Cavitation in peripheral walls
- Damages to baffle blocks
- Abrasion and impact damages on spillway and the stilling basin
Sika Solutions for Repair of Dams
Sikadur?-52, Sikadur?-451, Sikadur?-53
Epoxy low viscosity crack injection materials for dry or moist fine cracks (0.2 mm);
Epoxy grout water displacing for cracks (>0.5 mm) filled with water (without pressure).
Sika MonoTop?, SikaTop?
Complete range of cementitious polymer modified mortars, for the repair of concrete structures.
Sika MonoTop?-3400 Abraroc
Especially developed as wet abrasion resistant mortar for the repair of spillways, stilling basins, water channels, etc.
Sikagard?, Sika? FerroGard?
A range of hydrophobic impregnation, rigid and flexible protective coatings to protect concrete structures against ingress of deleterious elements; a range of surface applied corrosion inhibitors and galvanic anodes to prevent/reduce corrosion of embedded reinforcing steel.
Special structural adhesives for anchoring all types of fittings and equipment to structures such as for the installation of cable trays or other services, drainage pipes, inspection access equipment, etc., according to European and American standards.
Sika’s Experts Provide Assistance to Benefit your Business
Contact a Sika expert near you for technical support and locally available products and systems.
Contact Sika's global representative in case you need our support in an international project.
See Some of Sika’s Past Dam Projects
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1Source: WRD (World Register of Dams by ICOLD, the International Commission on Large Dams)
2Source: "2018 World Atlas and Industry Guide" by ICOLD
3Source: "2018 Hydropower Status Report" by IHA (International Hydropower Agency)
4Source: IEA (International Energy Agency)