Semi-prefabricated building system

The semi-prefabricated system enables quick and simple installation of objects. Blank casings for doors and windows are built into the treated prefabricated wall elements, as well as distribution boards for electric installations and other installation holes.

PDF catalogue - Semi-prefabricated building system (HR)

Characteristics of the system:

MAIN STRUCTURE of the object - load-bearing transverse and longitudinal walls - is made from the Beton-Lučko semi-prefabricated elements. The walls consist of two concrete slabs 5-6 cm thick, MB 30, connected together using trusses, with built-in wall reinforcement and additionally concreted centre (on site), which is the same as with monolithic RC walls with additionally concreted centre. Blank casings for doors and windows are built into the finely finished fabricated wall elements, as well as distribution boards for electric installations and other installation holes.

CEILING STRUCTURE consists of narrow prefabricated RC omnia panels, produced by Beton Lučko d.o.o., MB 30, subsequently made monolithic through concreting. Omnia panels are 5-6 cm thick, with built-in reinforcement of the lower zone and with trusses. On site the panels are joined together and the upper zone is reinforced, and the ceiling panel is concreted up to its full height. Distribution boards for electronic installations are built into the omnia panels as well as all necessary holes and openings.

FAÇADE WALLS are done in three ways, which ensures permanent protection of the building:

• They can be produced as load-bearing concrete walls, on the outside covered with thermal insulating panels (expanded polystyrene), covered with cement glue + façade protection.
• Façade walls can be produced as load-bearing RC walls, on the outside covered with thermal insulating panels and coated with RC treated façade elements (single leaf walls) which together make a ventilated façade.
• Façade walls can also be produced with prefabricated RC three-layered treated façade elements which fill out the entire opening between the transverse load-bearing walls of the building and which can be filled in or can contain a hole for a loggia or for installing windows and doors.
• Openings between the transverse load-bearing walls on the façade can be completed as RC prefabricated façade parapets that have been treated.
• PREFABRICATED FLIGHTS OF STAIRS are installed in the spaces determined for their installation. Flights of stairs are RC elements produced as a flat flight of stairs of variable dimensions or a double-flight spiral staircase of standard dimensions. The flat flight of stairs is a part of a single, double, or triple flight staircase and serves as the main staircase in residential buildings or in buildings intended for public use, and the double-flight spiral staircase is used for communication within multi-storey flats as well as secondary staircase in buildings.

Advantages of the system:

• fast and simple installation without wall and ceiling cladding, and with reduced need for support
• less reinforcement work during construction
• installation of blank casings for doors and windows
• installation of distribution boards
• due to a smooth finishing of the surfaces, there is no need for plastering, but only for final skim coating and painting
• an immediate result of the mentioned advantages are significant financial savings.

FREEDOM OF DESIGN The described construction system offers absolute freedom of design, as with monolithic RC constructions.

INSTALLATION OF ELEMENTS Installation of prefabricated elements is done according to the plan delivered to the client together with the prefabricated elements and prepared by the group of constructors of Beton-Lučko, who use modern technologies and equipment. As part of the installation plan, we also deliver the other documentation, namely workshop drawings of prefabricated elements and all the details on the horizontal and vertical joints of elements necessary for installation of reinforcement on site and for inspection of the competent organ, as well as for its control.

TRANSPORTATION OF ELEMENTS Prefabricated elements are shipped to the construction site by special vehicles of Beton-Lučko: flatbed trailer, specialized truck for transporting concrete products, or trailer truck. Transportation of prefabricated elements on site is done using a tower crane or truck crane.

STATIC TREATMENT As regards the static treatment, the described system corresponds to the monolithic RC structures because it enables incorporation of calculated reinforcement into the prefabricated walls and omnia panels, as well as quality production of all reinforcement overlaps within the central monolithic core, all further to the "Ordinance on technical standards for concrete and reinforced concrete" and "Technical Regulations for Construction of Buildings in Seismic Regions".

Omnia ceiling panels

The ceiling structure is done using OMINA prefabricated panels of Beton-Lučko d.o.o. The panels are made from lightweight concrete, density of 1000 kg/m³, reinforced with trusses and lower chord reinforcement. OMNIA panels are between 10 and 12 cm thick. Lap and upper chord reinforcement is done on site, after which it is concreted using regular concrete until it achieves its full thickness of 16-20 cm. The thickness of the panels is chosen based on the load-bearing calculations. In this way we get a monolithic ceiling construction, weighing from 250 to 320 kg/m². Distribution boards and all necessary holes are done before the reinforcement.

Prefabricated flights of stairs

Flights of stairs are RC elements produced as a flat flight of stairs of variable dimensions or a double-flight spiral staircase of standard dimensions. The flat flight of stairs is a part of a single, double, or triple flight staircase and serves as the main staircase in residential buildings or in buildings intended for public use, and the double-flight spiral staircase is used for communication within multi-storey flats as well as secondary staircase in buildings.

Concrete walls (double sided)

The walls are produced from semi-prefabricated elements, namely two OMNIA panels 6 cm thick. The panels are coupled using trusses and reinforced with mesh reinforcement. Such accurately prefabricated elements are installed on site and serve also as "cladding" to be filled with lightweight concrete. Usual concrete density for OMNIA plates is 1000 or 1200 kg/m³, and density of the infilling done on site is 800 or 1000 kg/m³. Concrete density is chosen based on the calculation of load-bearing and of thermal characteristics of the wall. The space between the prefabricated elements can be adjusted, depending on the wall thickness in the design. Before filling, the reinforcement for connecting the walls or walls and panels is set up on site. Detailed analyses of this system have confirmed that the wall can be treated as a wall that was constructed completely on site. In the performance stage the wall is propped at certain distances at the height of 1.5-2 metres, so as to prevent any buckling of prefabricated elements.