RCC Precast Box Culverts

Box culverts are a versatile product used commonly as conduits under or over roadways, railways, etc. to provide cross drainage or to take electrical cables from one side to other. They can also be employed to build underpasses for pedestrians or be used as service tunnels for a variety of applications.

Designs are dependent on project specifications and applications. Lateral earth loads from soil and hydrostatic loads from ground water. Vertical loads from the cover soil and live loads above. Surcharge loads from nearby impact loads. Seismic loads where applicable. After determining the size and design parameters required the appropriate ISO standards are used to provide the most economical design.

Viswak’s Box culverts are cast using concrete with a low w/c ratio; it is poured into steel mechanized equipment called precast molds. Rebar is preplaced and secured inside the mold. Form vibrators are used to consolidate concrete to attain homogeneity and release any trapped air. Hole formers may be incorporated, or coring is done if needed. The product is then stripped and the mold is reused.

At every stage meticulous testing is done to maintain quality. Every concrete batch undergoes cube testing to ensure strength parameters are met along with slump testing to ensure consistence in the mix design. After demolding the product goes through visual inspection to ensure no honey-combing, voids or cracks are present. In case any test fails the batch will be rejected.

installed with ease - Box culverts

Viswak’s U-drains are designed to be installed with ease, requiring very little excavation to place and a minimal amount of backfill. Viswak’s box culverts are supplied with lifting anchors to make lifting and placing both easy and precise.

• Soil excavation followed by base preparation; levelled to ensure easy alignment of box culverts and prevent settling of soil. In the case where the water table is located in the trench zone, dewatering methods must be employed to remove the water.
• Backfill of soil should be granular and be compacted layer by layer beginning form the side walls to top of the box sections to attain the required minimum density.
• Bends can be designed during manufacturing to allow for curved pathing during installation.
• Male/Female joints are provided for Viswak’s Box Culverts to slide and lock into place. Furthermore, erosion control seals, rubber rings, exterior joint wraps, expanding water stop seals or grouts can be used to make the joints watertight as required.