A versatile and indispensable material in contemporary construction is hydraulic concrete. It is extremely useful for projects involving underwater structures, dams, and bridges because it has the unusual ability to set and harden under water, unlike ordinary concrete. The hydraulic properties of this unique variety of concrete give rise to its name; that is, even in the presence of moisture, it can acquire strength and durability.
Hydraulic concrete comes in a variety of forms, each designed to fit particular uses and environmental circumstances. Common varieties include self-healing concrete, which is made to automatically fix cracks that may develop over time, and high-performance concrete, which provides remarkable strength and durability. To improve its performance in demanding circumstances, each variety is made with particular treatments and additives.
What distinguishes hydraulic concrete from traditional mixes are its technical features. Because of its exceptional resistance to chemical and water erosion, structures will stay intact and functional for longer. The composition of the mixture usually consists of fly ash, slag, and special cementitious compounds, all of which improve the mixture’s workability and durability.
It is essential for engineers and builders to comprehend the various varieties and technical characteristics of hydraulic concrete. It enables them to choose the ideal combination for every project, guaranteeing peak performance and durability. Hydraulic concrete is a fundamental element in numerous engineering endeavors, be it building a skyscraper dam or a submerged tunnel.
- General information
- Types
- Materials
- Requirements and specifications
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General information
GOST 4795-53 hydraulic concrete is designed for building structures or parts of them that come into contact with water on a regular or continuous basis. Its many qualities help ensure the long-term viability of these structures under these circumstances.
Types
The following design variations are allowed by the GOST for hydraulic concrete, depending on how the specified structures are operated:
- Location of structures relative to the water level:
- underwater — permanently in water;
- above-water — structures located above the variable water horizon.
- Scale of erected structures:
- massive;
- non-massive.
- According to the placement of this type of structures relative to the spheres of influence:
- designs of the internal zone;
- outdoor.
- Depending on the strength and current water pressure:
- pressure structures;
- free-flow.
The purpose and operational requirements of each unique case (thin-walled, massive, prefabricated, etc.) as well as the climate of the area where the designed structures will be placed determine the composition of hydraulic concrete and the required strength grade for the construction of hydraulic structures.
The type and primary attributes of hydraulic engineering mixes are denoted by the following designations:
- BPT — underwater for thin-walled structures;
- BGT — for zones with variable water levels;
- BNM — above-water massive structures.
Materials
Depending on the technical requirements, the following types of cement are used as binders for hydraulic engineering concrete:
- Portland cement;
- slag Portland cement;
- plasticized;
- hydrophobic;
- pozzolanic;
- sulphate-resistant.
Puzzolanic cement is distinguished by its elevated density of cement stone, low heat generation, and strong chemical resistance to exposure to fresh or mineralized waters on structures. Moreover, the mixture made with this material has poor frost resistance but low water separation.
It is advised to use hydrophobic or plasticized cement in harsh climates and locations with varying groundwater exposure. These grades enable the creation of waterproof and frost-resistant materials. At the same time, cut back on heat transfer during mixture hardening by 8–10% and binder consumption.
Sulfate-resistant cement is used in the presence of chemically aggressive waters and in exceptionally harsh operating conditions.
For above-water structures, slag Portland cement or Portland cement enhanced with mineral additives is utilized.
Materials are used as large and small fillers in accordance with GOST 26633-2012. To boost density, mixtures can have microfillers added to them; typically, these are fly ash (see photo).
Water permeability and frost resistance are controlled by adding modifiers:
- Plasticizers (0.1-3.0%):
- sulfate-yeast mash (SYM);
- neutralized air-entraining resin (NAER);
- organic silicon additives (GKZh);
- superplasticizer C3.
- Structural sealants (0.5-1%):
- ferric chloride;
- calcium nitrate (saltpeter);
- potassium or sodium silicate.
- Hydrophobic additives (0.15-1.0%):
- sodium oleate;
- calcium stearate;
- zinc stearate, etc.
Requirements and specifications
When designing and choosing concrete for hydraulic structures, the following fundamental specifications are taken into consideration:
- water resistance;
- water resistance;
- frost resistance;
- limited heat release during hardening;
- minimal shrinkage;
- positive deformation capacity;
- abrasion resistance when exposed to water pressure, sand deposits, etc.
- compressive strength — classes B5–B35;
- axial tensile strength — Bt 0.8–Bt 3.2;
- water resistance — W2–W20;
- frost resistance grades — F50–F600.
Advice: When choosing a brand for frost resistance, consideration is given to the local climate as well as the number of anticipated cycles of freezing and thawing throughout the year.
Large volumes of hydraulic concrete are placed quickly and efficiently in structures. In this sense, they are also subject to specific requirements that limit heat emission indicators during the mixture hardening process.
Reducing thermal shrinkage and cracking in large arrays of hydraulic structures are the reasons behind the allowed temperature increase of solutions during the hydration period.
For these purposes, the following heat emission reduction measures are outlined in the instructions for use:
- cooling of fillers;
- addition of crushed ice at the time of preparation of mixtures.
Because it can solidify underwater, hydraulic concrete is a highly adaptable building material that is perfect for submerged foundations, bridges, and dams. Hydraulic concrete comes in a variety of forms, each with unique qualities designed to meet various building requirements. Its setting time, strength, and durability are important technical attributes that are determined by the mix design and the kind of hydraulic binder utilized. To ensure safety, longevity, and cost-effectiveness when choosing hydraulic concrete for your project, it is essential to comprehend these factors.
| Type | Technical Characteristics |
| Regular Hydraulic Concrete | Strong, durable, suitable for most construction projects. Sets and hardens underwater. Commonly used in foundations, dams, and underwater structures. |
| High-Performance Hydraulic Concrete | Greater strength and durability. Improved resistance to environmental factors. Ideal for demanding projects like high-rise buildings and bridges. |
| Self-Consolidating Hydraulic Concrete | Flows easily, fills formwork without the need for mechanical vibration. Excellent surface finish and reduced labor costs. Used in complex and intricate structures. |
| Fiber-Reinforced Hydraulic Concrete | Enhanced tensile strength and crack resistance due to added fibers. Suitable for pavements, industrial floors, and structures requiring high impact resistance. |
Because of its exceptional capacity to solidify and harden in submerged conditions, hydraulic concrete is an invaluable material for a wide range of construction projects—particularly those involving submerged structures or environments with elevated moisture content. The main factors behind the widespread use of this kind of concrete in infrastructure projects such as bridges, dams, and other structures are its strength and versatility.
Various varieties of hydraulic concrete, including Portland cement, high-alumina cement, and slag cement, offer unique advantages and are chosen in accordance with the project’s particular specifications. Slag cement improves workability and resistance to harsh environments, while Portland cement is renowned for its longevity. High-alumina cement provides quick strength development. It is easier to select the appropriate material for a given construction project when one is aware of these types.
Hydraulic concrete’s technical attributes, such as its compressive strength, setting time, and resistance to environmental influences, guarantee its dependability and effectiveness. It is the material of choice for engineers and builders who want to create sturdy, long-lasting structures because of its capacity to retain integrity under difficult circumstances.
In conclusion, the numerous varieties and technical characteristics of hydraulic concrete highlight its significance in contemporary building. Building professionals can attain the best outcomes and guarantee the safety and durability of their projects by choosing the right kind for the given circumstances. This durable material is still essential to the global advancement of infrastructure development.
