Summit fabricates and makes available on a project-based temporary basis its steel and other advanced material casting molds to the contractors under Limited Use Agreements.
Summit’s StructCrete™ Precast Concrete Panel System (the “StructCrete™ System”) is the core of its project construction services business. The System consists of:
- precision steel molds,
- custom insulating mold wraps, panel de-molding and other equipment and tools (the “StructCrete™ Equipment”),
- special consumable materials used to cast and erect the panels, including mechanical-electrical-plumbing (MEP) conduit-formers, panel attachment hole-formers, panel attachment bolts, cast-in polymer-composite pads (to enable items to be attached to/hung from the concrete more easily), and green, high-performance grouts/seals,
- the method for panelizing the design of the building/structure,
- the method for manufacturing the panels, including the concrete mix design, location/placement of the rebar and steel wire mesh in the molds, pouring the concrete and ensuring it fills the mold, removing the cured panel from the mold, cleaning maintaining and storing the molds, and handling and moving the panels, and
- the method for erecting buildings with the panels, including placement of the panels, sealing the edges of the panels, and placement and tightening of the panel attachment bolts.
A cast panel has one side flat and the other side is “waffled” (i.e., ribbed). The thickness of the flat side, or web, and depth of the ribs depend on the overall size of the panel to be cast. Before concrete is poured into the mold, reinforcement steel (“rebar”) is placed in the ribs and around the perimeter. Steel wire mesh is then placed across the entire solid face of the panel. As required, attachment pads also are placed in specified locations at the ends of the ribs and on the face of the web. Special devices, called “chairs”, are used to hold the wire-mesh and rebar in precise locations in the mold. Other devices are also precisely placed in the mold to provide notches in the ribs where MEP pipes and wires can be run. Pre-cut holes in the mold allow “hole- formers” to be inserted prior to casting to create holes in the edge of the panel for the attachment bolts.
Concrete using standard Portland Type I cement with 3,500 to 5,000 psi cured compression strength is used for most applications. The custom insulated mold wrap retains the moisture in the concrete mix and heat of hydration generated by the curing concrete. This accelerates the curing, so that a minimum of 1 panel can be produced per mold per day and used immediately for erecting buildings. This is 3 to 7 times faster than other concrete construction methods.
The waffled panel design provides high structural strength while using less than 50% of the raw materials normally required for full-thickness cast panels, modular units or poured-in-place sections of the same size and structural integrity. This reduces the cost of materials, and the lighter weight panels require a smaller crane capacity than for ordinarily fabricated concrete panels.
The StructCrete™ System enables panels to be cast at the project site vs. being made in a factory and having to be trucked to the site. This is a significant advantage in countries like India where roads generally have many potholes and ruts and generally are of very poor quality.
With a simple way to locate rebar and wire mesh in the molds prior to casting, and precision-placed attachment holes in the panels, mostly unskilled labor is required to cast the panels and erect buildings. Comparatively, factory-manufactured modular units and the in-situ pour-in-place methods require skilled labor to assemble and place the required rebar cages and set-up the forming system. Additionally, the cure time is longer before the next floor or higher-up wall can be poured.
Temporary precision “block-outs” for doors and windows and other openings can be positioned exactly and easily in the StructCrete™ mold before the concrete is poured. Thus, a single mold can be used to make panels with diverse configurations of openings. Further, colors can be added to the concrete mix, and many types of decorative effects can be put on the flat face of the panel during the casting process. These include textures, patterns, designs and exposed aggregates.
The features of the StructCrete™ System provide Owners/Developers with combined time and cost savings that are unmatched by alternative methods.
The StructCrete™ mold consists of a steel flat base-plate set on a platform, side rails, and “domes” to form the webs. A special steel hinge is used to attach the side rails to the base plate. The hinge, which is welded to the edges of the platform and side rails, is designed to prevent leakage of the water in the concrete mix, as well as facilitate fast and easy removal of the cured panel, from the mold. The “domes” are welded or bolted onto the base-plate, as per design. The base-plate, side rails, and “domes” are constructed from standard, commodity plate steel that is commercially available from many sources worldwide. The “domes” are precision stamped employing standard commercial equipment in common use. Steel fabrication companies with the capacity to produce both the individual components and assemble the finished molds in very large quantities on a 3-shift assembly-line basis can be found in many countries, including India and other markets targeted by Summit. In markets where this capacity is not readily available, Summit has the operational capability to arrange for fabrication and shipping from the associated region to the project site.