The D-Shape building process is similar to the “printing” process because the system operates by straining a binder on a sand layer (more on materials in the next section). This is similar to what an ink-jet printer does on a sheet of paper. This principle allows the architect to design fantastically complex architectural structures.
Seen from the outside, D-Shape appears like a big aluminium structure inside of which the building will be constructed. CAD-CAM software drives the machinery during the building process. This structure holds the printer head, which of course is the real core of the new technology. Despite its large size, the structure is a very light and it can be easily transported, assembled and dismantled in a few hours by two workmen.
The process begins with the architect designing his project using CAD 3D Computer technology. The Computer design obtained is downloaded into a STL file and is imported into the Computer program that controls D-Shape’s printer head. The process takes place in a non-stop work session, starting from the foundation level and ending on the top of the roof, including stairs, external and internal partition walls, concave and convex surfaces, bas-reliefs, columns, statues, wiring, cabling and piping cavities. During the printing of each section a ‘structural ink’ is deposited by the printer’s nozzles on the sand. The solidification process takes 24 hours to complete. The printing starts from the bottom of the construction and rises up in sections of 5-10mm. Upon contact the solidification process starts and a new layer is added.
Surplus sand that has not been embedded within the structure acts as a buttressing support while the solidification process takes place. This surplus sand then can be reused on future buildings.
The new material has been submitted to traction, compression and bending tests. The results have been extraordinary! The artificial sandstone created has excellent resistance properties.
Effectively, the new process returns any type of sand, dust or gravel back to its original Compact Stone state. The Stone is very similar to Marble.
The binder transforms any kind of sand into a marble-like material (i.e. a mineral with microcrystalline characteristics) and with a resistance and traction much superior to Portland Cement, so much so that there is no need to use iron to reinforce the structure. This artificial marble is indistinguishable from real marble and chemically it is one hundred percent environmentally friendly.
Quality: D-Shape allows more advanced design and construction. The actual building will correspond to the CAD design to within planned tolerances of 5-10 millimeters. The type and complexity of the architectural styles (be it rationalist, neo-classical, organic, etc.) will not impact on building cost. In fact, as the system does not require moulds for concrete casting, any feature conceived by the designer can be easily printed.
Quantity/Time: The system is estimated to be four times faster than traditional building methods. Furthermore, the required operating time is known in advance allowing accurate planning for the machinery and for resources. The annual production capacity of the first (smaller) model of D-Shape will be of 2500 m², which is equivalent to twelve two floor buildings.
Costs: despite the higher cost of the binder compared to Portland cement, the realization costs of D-Shape structures are 30%-50% lower than manual methods.
Safety: no human intervention means substantially reduced risk of accidents. The building industry is affected by a higher incidence of injures and mortal accidents than many other industries. Severe and expensive safety measures must be constantly applied on the yard during building construction. D-Shape would lower the costs in terms of both human lives and financially.