Innovation: Duplex Blockmaker
Ecological building will always be successful when architecture and building physics are effectively coordinated. Selective use of function-integrating construction elements that combine insulating and structural materials in the building structure can significantly contribute to reducing energy requirements. The production of dual-shell blocks currently still takes a long time and requires high storage capacity, because the individual components are manufactured one after the other with the necessary hardening times. In most cases, they must be manually reworked.
In order to improve the product quality and dimensional accuracy of dual-shell blocks and to optimize production costs, the companies Knauer Engineering GmbH Industrieanlagen & Co. KG, and IAB Weimar, developed an innovative blockmaker with a vertical production process. This blockmaker processes two no-slump concrete mixes “fresh on fresh” in only one form to manufacture hybrid multifunction blocks over 300 mm in height. The block mantle, which assumes the loadbearing function, is manufactured first. This mantle later serves as formwork for the insulating core. For this process, the new Duplex Blockmaker requires only a single production station. The multifunction block remains during production at its place and will be moved to a standard production board only at the end of the cycle. This method ensures simplified functional integration and offers many advantages. In developing the new blockmaker, the focus was on a fast cycle sequence and green strength after demolding.
BMWi-sponsored Project
In realizing the BMWi-sponsored project, new and demanding requirements to be placed on the construction material mix had to be taken into account. To satisfy this requirement, technical laboratory tests utilizing various types of lightweight aggregate were performed. Criteria to be met were dry density, green stability and compressive strength as well as recyclability. In addition to construction materials analyses, various compaction variants were investigated with forced harmonic stimulation, by means of numeric software, with simulation and testing on a test rig. The most significant findings gained from these preliminary investigations provided information on the compactability of the mix, its interactive adhesive properties and the demolding and/or coring of the finished multifunction block.
An essential instrument, and accordingly a crucial step on the way to the prototype, was the preparation of a complex functional pattern with which the automated process sequences were able to be tested. By completion of the project, in April of 2018, production of the initial small-scale series succeeded with this functional pattern. Presently, a machine concept with several form chambers is being prepared, to implement the principle in actual practice.
In summary, the Duplex Blockmaker offers the following advantages:
Cost-effective process sequence and speed-up of production by eliminating curing times of individual constituents
Space savings by elimination of intermediate storage areas
Reduction of the required production periphery down to one machine
Elimination of manual work for the installation of insulation materials
Hybrid and recyclable construction products (cradle-to-cradle), with supporting and insulating functions
Smooth and fast construction sequences by the great dimensional accuracy of the blocks
Elimination of insulation work on buildings
With respect to more efficient production, the new Duplex Blockmaker has earned good marks. From the standpoint of the manufacturer of dual-shell blocks, this technology – with its considerably shortened production times – meets the requirements for becoming a growth engine. Not least as seen in this context, the market relevance of function-integrating construction elements will significantly increase for construction of energy-saving buildings.
