The safety barrier from a slipform paver

In the course of the construction of an in-situ concrete safety barrier by offset paving in Suzhou, China, the Wirtgen SP 15 impressed with outstanding quality and efficiency

Suzhou (Anhui Province), China – a number of demanding project requirements had to be fulfilled in the course of the construction of concrete safety barriers on a motorway bridge in Suzhou (China). Apart from compliance with strict safety requirements, these also included making the surface of the concrete safety barrier as smooth as possible. A project simply made for the compact Wirtgen SP 15 concrete paver. It not only fulfilled the demands for premium paving quality, but also those regarding the cost-efficiency of the process.

The SP 15 paved the concrete over a preplaced rebar cage. This steel construction lent the safety barrier additional stability and crash resistance.

Paving of safety barriers with a length of 2,300 m

Construction project in the city of Suzhou (pop. 5.7 million) in China’s Anhui Province: Lead contractor Henan Yuyong paved safety barriers with a length of around 2,300 m along both sides of a newly built motorway. The paving crew constructed the barriers by offset paving of wet concrete with a Wirtgen SP 15 slipform paver. The tight project schedule meant that the work could not have been achieved on time with formwork and manually-poured concrete.

The safety barriers were constructed along a section of the motorway passing through a suburban area and crossing the Beijing-Shanghai rail link and the Tuohe River on two bridges. This meant that a major part of the concrete safety barriers, amounting to around 1,450 m of the overall length, was paved on the bridges.

First-class paving results: the SP 15 didn’t just pave the concrete – it also compacted it and made sure it had the required visually appealing surface finish.

The SP 15 concrete paver uses the offset slipform paving method

Machine-paving of safety barriers with Wirtgen offset slipform pavers has numerous advantages. The offset paving process is more economical than manual pouring of concrete in rigid formwork or the use of pre-cast concrete elements. Offset means that the paving mould is mounted on the left or right side of the slipform paver. This enables the machines like the Wirtgen SP 15(i) to pave not only roadways, paths and traffic infrastructure surfaces, but also high monolithic profiles such as safety barriers. The enormous variety of possible profiles makes the machines ideal for a wide range of applications and assures high machine utilisation rates.

The Wirtgen SP 15(i) slipform paver also reliably masters a whole range of challenging tasks. To ensure that nothing was left to chance on the construction site in Suzhou, the paving crew from Henan Yuyong completed a number of contracts beforehand with the offset slipform paver and thoroughly tested the machine before the project began. Prior to the project, the machine had already impressed the crew – not only with its precision machine control system, which assured process reliability and exact steering, but also with the outstanding quality of the paving results. At the same time – with the assistance of cross-slope control – the electronic steering and drive system reduced the paving crew’s workload by automatically compensating for unevenness. A further option, AutoPilot 2.0, a machine control system developed by Wirtgen for stringless paving, assured highest precision and efficiency.

The safety barrier from a slipform paver

Highlights of the Wirtgen SP 15(i) slipform paver

  • Compact offset slipform paver for paving concrete surfaces with a width of up to 2.2 m and monolithic profiles with a height of up to 1.3 m
  • The SP 15(i) concrete paver is ideal for use on construction sites where a high degree of manoeuvrability, a tight steering radius and maximum flexibility are required.
  • The two track units with parallelogram swing arms at the front and a repositionable track unit at the rear enable zero-clearance paving and maximum flexibility.
  • The SP 15(i) can be precisely guided by stringline scanning, the Wirtgen AutoPilot 2.0 stringless guidance system, or 3D applications

Versatile SP 15(i) concrete paver for a wide range of applications

The Wirtgen SP 15(i) is an extremely versatile offset slipform paver that is the ideal choice for the paving of a wide range of concrete structures. Its paving mould can be laterally shifted by means of a hydraulically-activated telescopic suspension mounting. This feature enables profile paving between or to the side of the three track units. To a great extent, the independently steerable, height-adjustable, hydrostatically-driven track units, the slipform paving mold, and the concrete feeding system are freely positionable. Even greater versatility is offered by the single, mechanically, or optionally hydraulically, positionable rear track unit. When paving safety barriers, as in Suzhou, the paver is frequently positioned close to the barrier being paved, which adds to the stability of the concrete paver.

The compact offset slipform paver is suitable for an extremely broad spectrum of applications. Thanks to its ability to pave a wide range of profile geometries, the SP 15(i) is the ideal choice for cost-efficient and precise paving of structures such as kerbs, gutters, drainage channels and drains, as well as safety barriers. Uniform and correct compaction of the concrete is essential for assuring the structural integrity, high strength and surface quality of the monolithic profiles. To ensure this, up to five vibrators can be positioned inside the offset mould. Machine users can choose either hydraulic or electric vibration. Thanks to its compact dimensions, the offset slipform paver is ideal for use on sites with restricted space and easy to transport from one job to the next.

The safety barrier from a slipform paver

"The SP 15 impresses with a state-of-the-art machine concept, compact construction, and outstanding performance. The precision of the paving results is also excellent."

Site Manager of the project in Suzhou

The SP 15 ensures that the experienced crew delivers on time

Lead contractor Henan Yuyong has many years of experience in working with concrete on road construction projects. The crew is visibly impressed by their Wirtgen SP 15 slipform paver: "The SP 15 impresses with a state-of-the-art machine concept, compact construction, and outstanding performance. The smart electronic steering and control technology is extremely sensitive, and that’s what guarantees the outstanding precision of the paving results." The building inspectors responsible for the project couldn’t have agreed more. They gave their seal of approval for the in situ paved concrete safety barrier without raising a single objection.