Precision concrete paving over a length of 30 km

An SP 94 slipform paver and a TCM 180 texture curing machine from WIRTGEN were deployed to widen National Highway 73 between the towns of Barnala and Moga near the border with Pakistan.

The traffic policy for the maintenance and development of the countrywide infrastr­ucture has been leading to a large number of infrastructure projects. Mobility is, after all, absolutely essential for India to sustain its explosive economic growth. Innovative and high-performance machine technologies, in addition to efficient construction methods, are playing a crucial role in ensuring the long term functionality of the road infrastructure.

 

Economic Concrete Paving

Concrete construction has been booming in India over recent years, being preferred to asphalt in the majority of road projects. Concrete is a very resilient material that is traditionally used on areas with high volumes of traffic and heavy trucks as well as areas exposed to high spot loads, such as airports and container terminals. The highest performance slipform pavers from Wirtgen assure the economical production of high quality concrete pavements.

Client Builds on Wirtgen Technologies

The responsibility for the operation and expansion of the road network lies with the National Highways Authority of India (NHAI), acting on behalf of the government. Although these National Highways account for only 2% of India’s roads, they handle some 40% of its total traffic. This made it all the more urgent to widen the section of road on the new NH 703 between Barnala and Moga from 2 to 4 lanes. The contract for this work was awarded to VRC Construction.

 

Climatic Challenge

During the 18-month project the Wirtgen SP 94 precisely paved the two new concrete lanes over a length of 30km. In the extremely hot summer months, a large part of the work was performed in the milder temperatures of the night, since excessive heat has a negative impact on the concrete paving operation and can affect the quality and durability of the pavement. To prevent the concrete from drying out too quickly and then cracking under stress, it was also vital to cure the fresh concrete immediately afterwards. For this reason the TCM 180, also from Wirtgen, followed directly after the slipform paver, applying the curing compound, while at the same time texturing the paved surface, by means of its automatic spraying and texturing system.

 

Powerful SP 94

The SP 94 was perfectly at ease in paving these new concrete surfaces, 9m wide and 30cm thick. The mid-size inset paver can optionally pave widths up to 9.5m and 450mm thick included multiple crowns. Its powerful 224kW engine guarantees the ability to run a wide array of options while maintaining the highest fuel efficiency and the lowest noise levels, thanks to the ECO mode feature that automatically adjusts engine output to the current performance.

The Wirtgen  concrete paver was equipped with the automatic Dowel Bar Inserter (DBI). The smooth dowel bars are placed where later the joints will be sawed to induce the controlled cracking and have the function of load transferring between slabs while allowing them to move longitudinally but not to be displaced vertically. By contrast, the corrugated bars inserted automatically by the Tie Bar Inserter tie the two lanes together and prevent them from moving apart.

 

High Smoothness

To achieve optimum evenness of the new concrete surface, the transversely Oscillating Correcting Beam (OCB) of the SP 94 first corrects the irregularities produced by the insertion of dowels and tie bars. Then the final finish – before the TCM 180 carries out the texturing and curing of the new surface – is provided by the Super Smoother. Its ski, floating on the concrete, generates surface evenness by a combination of longitudinal and lateral movement. The TCM 180 follows immediately behind the SP 94, ensuring that the paved concrete is textured and cured properly.

 

Precision in Every Condition

In addition to its excellent productivity, the SP 94 also offers a wide range of applications. The inset paver achieves the latter partly due to its 4 steerable and pivoting crawler units, which not only make transport easier but also mean the machine faster to maneuver and set up on site. The ability to adjust the steering angle sensor of all crawler tracks entirely automatically allows varying job site conditions to be handled easily. “The SP 94 is very maneuverable and can precisely pave in all sections, including on the bends of the NH 703”, explains S P Singh, Project Manager of VRC Construction.

The computer-aided speed adjustment of every single crawler track paired with the most sophisticated elevation and leveling control ensures to meet the tightest pavement smoothness specifications. In accordance with the project requirements, the TCM 180 texture curing machine delivered the desired surface texture and applied the curing compound. For the latest model of the machine, Wirtgen has expanded the spectrum of possible surface texturing options. The proven transverse texturing and spraying functions, for instance, have now been joined by longitudinal tining and spraying, while a diagonal texturing and spraying pattern option has also been made available upon request.

Furthermore, the TCM 180 can be fitted with mounts for a burlap or synthetic turf. The film unwinder (polyroll) also enables the concrete to be protected quickly and effectively against negative influences caused by the sudden onset of rain.

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