Correct drainage analysis by composition begins with an analysis of the load on the surface, since it is this parameter that dictates the choice of the strength class of trays and gratings. Incorrect selection of materials leads to destruction of the concrete screed around the channels after the first winter or deformation of the polymer walls under the weight of transport. Engineering precision in calculating capacity prevents the formation of puddles and ice, which are the main enemies of the road surface and building foundations.
Structurally, the system is not just a trench in the ground, but a complex engineering unit consisting of several interconnected elements. Storm drain is the main transporting element that absorbs the flow of water from the surface. Its geometry should ensure laminar flow, minimizing hydraulic resistance and preventing siltation of the bottom.
For the effective operation of the entire system, it is critical to have sand trap, which is mounted at the beginning of the line or at certain intervals. This element traps large debris, sand and leaves, preventing them from clogging the main highway or city storm drain. Without this component, regular cleaning of the system would be impossible without special equipment.
Completes a compound structure water intake grate, which takes the direct impact of mechanical loads. It must have high compressive strength and at the same time have sufficient open cross-sectional area to quickly collect water. The balance between strength and flow capacity is a key factor in the longevity of the entire drainage system.
Classification of tray materials: concrete, polymer concrete and plastic
The choice of material for gutters directly depends on the aggressiveness of the environment and the expected mechanical loads. Concrete trays Traditionally used in areas with high traffic and heavy vehicles due to their massiveness and abrasion resistance. However, the porous structure of regular concrete can absorb moisture and oils, leading to deterioration over time during freeze-thaw cycles.
Considered a more advanced material polymer concrete, which is a composite based on granite chips and epoxy resins. Such products have virtually zero water absorption and high chemical resistance. They are ideal for industrial areas where fuels and lubricants or reagents that corrode ordinary cement may get on the surface.
For private households and pedestrian areas, the optimal solution is plastic trays made of polypropylene or polyethylene. Their main advantage is their low weight, which simplifies logistics and installation, as well as a smooth internal surface, which improves the self-cleaning of the system. Despite their apparent lightness, modern plastics can withstand significant loads due to their ribbed design.
⚠️ Attention: When choosing concrete products, be sure to check the frost resistance grade (F), it must be at least F200 for Russian climate conditions, otherwise the trays will begin to crumble after the first winter.
Typology of water intake grids and their influence on hydraulics
The grid is the visible part of the iceberg, which performs a dual function: protecting the tray from mechanical damage and filtering large debris. The configuration of the holes directly affects the rate of water collection. Slotted grilles have maximum throughput, since their entire area is working, but they require more frequent cleaning of leaves.
Cellular and perforated options are more often used in park areas and on pedestrian paths, where aesthetic appearance and safety for women's shoes or bicycle wheels come to the fore. Load class The grating must strictly correspond to the class of the tray: using a light grating on a route will lead to its instant destruction.
The material used also varies from cast iron (for highways) to galvanized steel and plastic (for home areas). Cast iron products are highly durable, but require protection against corrosion and theft. Steel analogues are lighter and cheaper, but less durable in aggressive environments with the use of road salts.
Sand collection system and inspection wells
Effective drainage is impossible without a primary water treatment system. Sand trap Structurally, it is an expanded chamber with a recess, where the flow speed drops and heavy fractions settle to the bottom under the influence of gravity. Regular maintenance of this unit extends the life of the entire drainage network.
Inspection wells are installed at the turns of the route and every 30-50 meters of straight sections. They are necessary for access to the inside of the system in order to clear blockages and visually monitor the condition of the trays. Without them, maintaining the underground part of the drainage system turns into a complex engineering task.
Modern models of sand traps are often equipped with removable baskets, which greatly simplifies the maintenance process. Instead of scooping out dirt by hand or pump, the operator simply removes the basket and cleans it. This reduces the labor costs for maintaining the system significantly.
For regions with heavy leaf fall, choose screens with a larger clear area and install larger-capacity sand traps to reduce the frequency of cleaning.
Sealing joints and waterproofing joints
The quality of assembly of the drainage system determines its tightness. The joints between individual trays, as well as the points of connection with storm water inlets, must be reliably insulated. For this purpose, special grooves like tongue and groove or side drainage systems that minimize the number of seams.
During installation it is mandatory to use sealing mastics or special sealing profiles. The penetration of water through the joints into the underlying soil erodes the foundation, which leads to subsidence of the trays and the formation of cracks. This is especially critical for sandy soils with high water permeability.
At the points of connection to the main sewer, transition couplings are used to ensure a tight connection of pipes of different diameters and materials. It is important to observe slopes when connecting to avoid the formation of stagnant zones where an ice plug may form in winter.
⚠️ Attention: Never leave the joints of concrete trays unsealed, even if they fit tightly together. Vibration from transport will quickly break the contact, and water will begin to wash away the base.
Table: Comparison of load classes according to EN 1433
Understanding the load class labeling is essential to selecting the correct components. The European standard EN 1433 clearly regulates the maximum loads that drainage elements can withstand. Choosing a class with a safety margin increases the life of the system, but also increases its cost.
| Load class | Ultimate load (kN) | Typical Application | Recommended Material |
|---|---|---|---|
| A15 | 15 | Pedestrian areas, parks, bike paths | Plastic, polymer concrete |
| B125 | 125 | Car parking, sidewalks near garages | Polymer concrete, steel |
| C250 | 250 | Passenger truck passages, gas stations | Polymer concrete, cast iron |
| D400 | 400 | Highways, industrial zones, ports | High-strength concrete, cast iron |
| F900 | 900 | Airfields, special equipment areas | Special concrete, reinforced cast iron |
When calculating the load, it is necessary to take into account not only the static weight of the vehicle, but also the dynamic shock loads that occur during movement. The safety margin is especially important for systems laid under areas of possible braking or turning of equipment.
The main selection criterion is not the price of the tray, but the correspondence of the load class to real traffic. Saving on strength class leads to expensive repairs after 1-2 years.
Installation features and excavation work
The technology for laying drainage trays requires strict adherence to the sequence of operations. First, the soil is excavated to a depth that takes into account the height of the tray, the thickness of the concrete base and the bedding layer. The bottom of the trench must be leveled and compacted in compliance with the design longitudinal slope.
The base for the trays is made of lean concrete (grade no lower than B15) with a thickness of 10-15 cm. This creates a rigid platform that prevents uneven settlement of individual elements. Lateral fixation is also done by concreting to prevent horizontal displacement of the rows.
☑️ Checklist before pouring concrete
After the fixing concrete has hardened, the temporary spacers can be removed and the finishing coating can begin to be laid. It is important not to overload the newly laid structure in the first 7-10 days until the concrete gains the necessary strength. Violation of this regime can lead to distortions of the entire line.
Is it necessary to make expansion joints during installation?
Yes, expansion joints are required when the length of the straight drainage line is more than 10-12 meters. They compensate for thermal expansion of materials and prevent cracks in the concrete frame. The seams are filled with elastic sealant or bitumen mastic.
Can trays be cut to size?
Polymer and polymer concrete trays can be sawed with a regular hacksaw or grinder with a diamond blade to adjust the length. Concrete products are more difficult to cut; this requires special diamond-coated equipment, and there is a risk of damaging the reinforcement inside.
How often should the drainage system be cleaned?
The recommended frequency of maintenance is 2 times a year: in the spring after the snow melts and in the fall after the leaves fall. In industrial areas or places with high pollution, the frequency of inspections should be increased to 4 times a year.