New paving of the pedestrian zone in Homburg/Saar
When it comes to pedestrian-friendly paving of inner-city streets, two aspects are often paramount: firstly, stability, so that the surfaces are able to absorb the expected traffic loads without shifting, and secondly, appearance, as the street space should ultimately offer citizens an attractive quality of stay. However, both aspects – appearance and technology – often represent a contradiction. Pure asphalt surfaces, for example, are technically feasible but not very attractive visually. Conventional paved surfaces often look better, but are not always suitable for absorbing all traffic loads due to their lack of bonding effect. The district town of Homburg in the Saarpfalz district found a good solution for the renovation of its pedestrian zone.
With just under 42,000 inhabitants, Homburg is the third largest city in Saarland. When the energy supplier Steag announced a few years ago that the district heating pipe had to be replaced in large parts of the pedestrian zone, the city planners in charge decided that the old paving from 1982 should also be replaced. Roland Lupp, Head of the Department of Civil Engineering of the City of Homburg, explains the measure: “Although the old surfaces – consisting of natural stone bars and red concrete paving – were not in such a bad condition visually and technically, we wanted to take this opportunity to upgrade the pedestrian zone with a new surface design. We deliberately avoided natural stone paving in order to improve accessibility for wheelchair users and older people with walking frames. We were therefore looking for concrete paving that would visually match the modern lighting and the new benches, litter bins and planters,” explains Lupp.
Stable: single-stone paving with D-point joint protection
However, the issue of load-bearing capacity also played an important role for the planners. Roland Lupp: “The areas are frequently used by delivery vehicles. That’s why we were looking for a paving that was technically designed in such a way that it would not be damaged in the long term despite the shear and thrust forces exerted by these vehicles.” The CombiStabil paving system from Betonwerk Pfenning in Lampertheim was chosen for the approximately 2,600 square meters of paved surfaces. This system from the Einstein paving family combines aesthetics and functionality in an ideal way and therefore seemed particularly suitable to the planners responsible. Roland Lupp explains why: “To ensure that the joint required to absorb traffic loads is always maintained, this 8 cm thick paving has what is known as D-point joint protection. This ensures that there is only minimal contact at certain points on the bottom edges of the stones when they are laid. Unlike many other interlocking pavers with spacer or interlocking cam systems, the proportion of the surface where the stones touch is therefore very small. This prevents crunching and the joint required to absorb traffic loads is always maintained, thus ensuring optimum force transmission between the stones. Shear and horizontal forces caused by traffic on the pedestrian zone are buffered by the joint material and transferred evenly to the base courses,” says Lupp.
Beautiful: shot-blasted concrete paving enhances the street space
Thanks to its shot-peened surface, the new 18 x 30 cm paving has a very elegant look. The two colors used were carbon steel and manganese steel – a dark and a light shade of grey. Roland Lupp comments: “The paving fits in very well with the new street furniture – the square formats allow the surfaces to recede discreetly into the background and emphasize the mobile raised beds, which can be used to design the areas variably during events. All in all, this gave the entire street space the desired fresh look and a significant increase in the quality of stay. Thanks to the good properties of the paving in terms of load-bearing capacity, we can assume that the paving will last at least as long as the old surface from the 1980s,” concludes Roland Lupp.
