Wirtgen's SP 15i slipform paver addresses a specific and persistent niche in concrete infrastructure: the production of curb-and-gutter, sidewalks, and small-profile concrete structures that are too narrow for full-width slipform paving but too labor-intensive to form manually. The SP 15i's defining capability is its flexible mold positioning system - the machine's slipform molds can be mounted on either side of the tracked chassis, within the track envelope or offset beyond it, allowing the machine to pour curb profiles against existing structures (retaining walls, bridge abutments, building facades) without modification to the machine's core geometry.
The engineering significance of this offset-mold architecture is productivity. Traditional curb-forming methods require either a dedicated curb machine (which can only pour one profile) or a full-size slipform paver (which is oversized and costly for curb-only work). The SP 15i bridges the gap - its modular mold system allows a single machine to switch between multiple curb profiles, mount the mold on either side for work against existing infrastructure, and even pour profiles on both sides of the machine in certain configurations. When fitted with a Concrete Curber attachment, the machine transitions between sidewalk panels and curb profiles without requiring a second machine or a full crew change.
For slab paving work - where the SP 15i handles widths up to approximately 5 meters - the machine integrates an automatic dowel bar inserter (DBI) that inserts load-transfer dowels into the fresh concrete slab mid-paving, along with up to three automatic side tie-bar inserters for longitudinal joint reinforcement. This eliminates the manual dowel insertion that previously required workers walking behind the paver to drive dowels into wet concrete - a labor-intensive, quality-inconsistent process that the automatic inserter performs with precise positional and depth control. Combined with Wirtgen's Level Pro leveling system and the machine's electronic control platform, the SP 15i delivers smooth, dimensionally accurate concrete profiles at production rates of several hundred meters per shift, depending on profile complexity - positioning it as a productivity tool for curb, sidewalk, and small-slab work across municipal, commercial, and infrastructure projects.
