Idea of construction a precast concrete floor FILIGRAN type
FILIGRAN type floor is a permanent concrete formwork designed in accordance to PN-B-03264: 1999 ''Concrete, reinforced concrete and prestressed concrete construction.. It is mado up of large areas precast concrete slabs which is ''a lost shuttering. produced in a precast manufacture company and in-situ cast concrete.
Both floor layers are joint by lattice girders placed in an in-situ cast concrete and by rough precast element surface. That makes the layers as one monolithic concrete element and allows them to cooperate while bearing loads.
FILIGRAN floors are produced in width sizes range to 2500 mm and length up to 9m. Large areas of elements gives low number of conections, which are the weakest place in the floor (eg. Precast channel concrete elements).
Floor depth vary from 40mm to 70mm. The floor fire resistance depends on its depth and also increasing reinforcement cover dimension and concrete grade gives better control in protection against atmospheric influences.
There are, according to statics-material strength guidelines, tensile reinforcement and lattice girders (KT) in the slab elements.
Bottom reinforcement bars of lattice girders are part of needed span tensile reinforcment which also anchors well the girder in the precast concret slab. Lattice girders crossbraces bear uplift forces between precast concrete slab and in-situ screed.They can by account in calculations as bearing shearing forces.
Top reinforcing bars and crossbraces gives the floor required rigidity while the assembly and casting phase. Depth of the lattice girders are in dependance on floor depth.
Depth of composite concrete floors made up of precast FILIGRAN type elements are available in range from 100mm to 300m (slab floors) and from 150 mm to 360 mm (in case-slab floors). Floor thicknes is controled by the in-situ cast concrete layer thicknes. The strength of the floor (span dimension, affecting loads) depends on its thicknes. It has also influence on costs of a floor erection.
Floor slabs assembly is made with a crane with an appropriate load strenght. For example floor elements that are 50 mm thick have a mass of 125 kg/m. On client demand floor elements can be adjusted to the crane load. There is also possibility to produce elements for hand assembly though this is almost only for refurbishment works.
FILIGRAN floor are better than each other floor system.
"BPS-FILIGRAN" system eliminate or makes efective a lot of building works:
- floor elements shape is adjusted indyvidualy to the appropriate building object . there is no need to use any additional in-situ cast concrete
- there are all required holes for instalation infrastructure in the floor elements . there is no need to do them on site
- plain soffit surface eliminates need of making facing which takes a lot of money and works for a contractor or investor in further fase of building process. Finish works with FILIGRAN type floors takes only filling the joints
- puting reinforcement in an in-situ concrete cast prevents from skratches in floor during building exploitation phase
- there is a possibility to place a beam reinforcement in FILIGRAN type floors for beams placed partialy or hidden in floor depth. its no need to put any other costly shuttering
- high costs of traditional floor systems are triggered by need to keep floor slab satisfying deflection requirements. Only with FILIGRAN type floor there is a possibility to produce the elements with negative deflection which minimizes total costs
AIM AND USING RANGE:
"FILIGRAN" precast concrete formwork can be used in sort of floors as follows:
- monolithic slab floor
- ribbed-case floor
- ribbed-slab floor
- column-slab floor
- monolithic constructions untypical, eg. Stages, stairs, balcony slabs, havy roofs, etc.
- composite steel-concrete constructions in engineering objects
Range of using this system is practicaly unlimited. It can be used in one family houses, school buildings, hospital buildings, office buildings, garages and industrial objects as well as egineering constructions (eg. Bridges for pedestrians).
Precast concret "BPS-FILIGRAN" system floors can be used for every kind of load . dynamic. For the reason it doesnt limit the creative invention of architects and designers we can say "FILIGRAN floors can be placed insttead of every floor... "
JEDYNKA WROCŁAWSKA company designers advise which sort of concrete formwork floor system suits in order to minimalize the costs.
ADVANTAGES OF THE "BPS - FILIGRAN" FLOOR SLABS SYSTEM:
"BPS-FILIGRAN" floor slabs are called "lost concrete shuttering" for concrete floors. This system gives the best floor without use costly shutterings.
FILIGRAN type floor merges precast and in-situ cast concrete floor ideas. It is a new product . monolithic in a half floor which has all profits both precast and monolithic floor.
There are most important advantages of "BPS-FILIGRAN" system:
- shorten erecting time on site
- low transport costs (around 150m./lorry)
- possibility unlimited rebuild of internal walls while building process
- elimination of shuttering
- simplification of reinforcement works
- elimination of soffit facing
- unlimited shaped elements (arches, holes)
- big exploitation loads (>10kN/m.)
- designing freedom for architects/li>
- the best floor system for buildings on mine works influence areas