Böhl-Iggelheim renovates roads with CombiStabil – single-stone paving
The typical village street in a Palatinate municipality is characterized by a narrow roadway and houses that are built right up to the often very narrow sidewalks. The advantage: by dispensing with the front garden, the valuable garden space behind the house is increased. The disadvantage: due to the narrow development of the houses right up to the sidewalks, such streets often have an oppressive effect and offer only a low quality of stay for their residents. A good solution for such a street was found in the independent municipality of Böhl-Iggelheim, approx. 20 km south-east of Ludwigshafen am Rhein. Here, special measures were taken during the redevelopment of an inner-city residential street so that it is now increasingly used as a living space by local residents.
Goldböhlstraße in the district of Iggelheim had long ceased to be a really attractive street: a crumbling asphalt surface, far too little space for pedestrians and speeding traffic in this 30 km/h zone were a thorn in the side of local residents. A fundamental renovation of the approximately 400-metre-long road in 2019 should change this. Andreas Mangold from the planning office PISKE in Ludwigshafen describes the planning approach: “We repeatedly encounter the situation that the overall width of the road is too narrow to implement a classic separating construction with sidewalks and carriageway. In the past, sidewalks were often very narrow to make room for car traffic. As this type of separation was not possible, we planned a mixed traffic area with traffic-calmed signs,” says Mangold.
D-point joint technology offers perfect anti-displacement protection
For design reasons, the planners only considered a colored pavement that would visually enhance the surfaces. Due to the possible heavy goods traffic and the expected footpath crossings, the roadway and both footpaths as well as the mixed traffic area were given a superstructure in accordance with load class 1.8 according to RStO 12 with a 65 cm superstructure thickness. The paving should therefore also be able to withstand the traffic loads so that the roadway is not damaged in the long term. But which paving system fulfills these two criteria in the same way? The planners found what they were looking for in the “CombiStabil” system from Beton Pfenning in Lampertheim. This concrete paving from the Einstein paving family in 18 x 24 cm format has a special interlocking technology that allows a load of up to BK 3.2. This is due to the interlocking elements, which are arranged in pairs to prevent the stones from shifting against each other. To ensure that the joint required to absorb traffic loads is always maintained, this 10 cm thick paving is equipped with so-called D-point joint technology. This ensures that there is only minimal contact at 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 surface are buffered by the joint material and transferred evenly to the base courses.
Mixed traffic areas are more demanding in terms of design
Andreas Mangold: “This system is therefore also ideally suited for Goldböhlstraße. After all, it is not only used by cars, but also by refuse collection vehicles and delivery vans. Thanks to the special bonding effect of the paving material, these vehicles cannot damage the surface.” Another advantage of such a construction solution is its visual effect. Mangold explains: “Because the entire surface was paved in one piece, the entire street area appears wider – almost as if more space had beencreated between the closely spaced houses. In contrast to the previous asphalt pavement, the stones, which were laid here over 1,500 square meters in the color vine leaves, blend in very harmoniously with the surroundings and form a unit with the facades of the houses.” To avoid turning the 30 km/h zone into a racetrack due to the apparent widening, a further 1,000 square meters of the road was paved with the CombiStabil system in grey. This creates visual effects that are intended to help calm traffic. “In this area, the separation of the roadway and red sidewalk is deliberate, at least visually,” says Mangold.
Matching composite trough channel from the Einstein family
Another measure to enhance the street is a gray composite trough channel that visually divides the surfaces. This provides a good contrast to the paving and indicates the course of the road. The advantage: as the channel also comes from the Einstein family, the composite effect is maintained across the entire road surface. “The result is impressive,” explains Andreas Mangold. “The renovation has made Goldböhlstrasse much more attractive – in summer, you can see more life on the street again – the entire street space then becomes a living space for the residents, so to speak.” The planner is also convinced of the technical merits of this solution: “Despite intensive use of the areas since completion of the renovation, there have been no discernible adverse effects. According to the local authority, this solution will therefore be used again and again for other similar renovation projects,” says Mangold.