Progress Group, a company specializing in mechanical engineering and precast concrete systems, has introduced a proprietary 3D printing process known as Selective Paste Intrusion (SPI). Designed for large-format concrete parts, the SPI system achieves a layer resolution of three millimeters and is currently in operation at the company’s facility in Brixen, South Tyrol.
At this 3D printing center, Progress engineers produce both customer-specific components and experimental prototypes. The printer’s build volume, measuring 4 meters by 2.5 meters by 1 meter, allows for complex geometries and surface detail typically difficult to achieve with conventional methods. SPI enables targeted material deposition, reducing overall concrete usage by placing paste only where structurally necessary.
Rather than printing full-scale structures on-site, Progress is applying SPI to precast concrete production within a controlled factory environment. According to the company, this approach improves quality assurance, avoids weather-related delays, and ensures more consistent working conditions. Use cases include architectural façades, balcony elements, complex formwork, and specialized prefabricated units.
The SPI system was developed in-house by the company’s research and development team. Surfaces printed using this method exhibit notable precision, and the system’s three-millimeter resolution supports detailed formwork without relying on traditional casting molds. This is particularly relevant for limited production runs, where mold fabrication would otherwise be time- and cost-intensive.
Progress positions its additive manufacturing capabilities as a complement to conventional concrete construction methods rather than a wholesale replacement. By focusing on geometrically complex or low-volume applications, the company aims to expand design possibilities while reducing material waste and streamlining production workflows.
Expanding the Capabilities of 3D Printed Concrete
Researchers at the University of New Mexico (UNM) have developed a self-reinforced, ultra-ductile cementitious material tailored for 3D printing. Addressing the brittleness of conventional concrete, the team, led by assistant professor Maryam Hojati, incorporated polymer fibers into the mix, enabling it to withstand tensile and bending forces without the need for steel reinforcement. The project aimed to overcome one of the key limitations in 3D printing concrete: the incompatibility of traditional rebar with extrusion-based processes.
While the UNM team focused on mechanical flexibility, recent developments in material enhancement have emphasized thermal and structural performance. One example is the University of Virginia’s work on graphene-enhanced concrete, which seeks to improve strength and durability while reducing environmental impact. Graphene’s integration into cementitious materials enables denser microstructures, potentially decreasing permeability and extending structural life spans. Although primarily tested for cast components, the findings support wider interest in high-performance concrete formulations.
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Featured photo shows SPI-printed architectural façade prototype. Photo via Progress Group.
