Thermal Floors

thermal-1

O’Reilly Concrete Hollowcore Thermal Floor slabs are pre-stressed concrete elements with continues longitudinal voids formed using polystyrene void formers. Innovative casting system in the manufacture of pre-stressed flooring units gives many advantages comparing to traditional hollow core units:

  • better sound resistance
  • improved thermal efficiency
  • flexibility in design
  • structural efficiency

POLYSTYRENE VOID FORMERS

The standard width of the slab unit is 1200 mm. Slabs are manufactured up to exact site dimensions with pre-formed service opes where required. the range of depths and achievable spans cover all types of residential houses and the most of commercial, public and industrial buildings.

Benefits & Details

O’Reilly Thermal Floor slabs have closed solid ends; this eliminates risk of water or other contamination trapped in cores; no additional work on site is required to close open cores; solid ends also improve shear capacity of the slab and the upper floor wall can be built directly on the end of the slab
O’Reilly Thermal Floor slabs have big voids filled with polystyrene which reduces the overall weight of the slab; this means reduced dead weight and better ability to resist service loads, reduced loads are transferred to the foundations and smaller foundation size is required
All service openings can be easily formed in floor slabs at production stage; slabs are manufactured to the exact site dimensions
O’Reilly Thermal Floor slabs have a minimum fire rating of 1 hour; unlike extruded units they have closed solid ends which improves fire retardation
Due to manufacturing technol- ogy slabs are very flexible in terms of structural design; for example slabs can be designed as cantilevered

150 mm deep Hollowcore slab

Self weight of precast unit (without structural screed):  2.59 kN/m2
Concrete strength at service (28 days):  50 N/mm2
Concrete strength at transfer:  30 N/mm2
Prestressing strands: 7 wire 9.3 mm strand
Prestressing: 70% fpu
Maximum number of strands: 14
Cover to strand: 25 mm
Fire resistance (BS8110: Part 1:1997; Table 4.9): 1 hour
Minimum required effective bearing width (BS8110: Part 1:1997; Clause 5.2):
On concrete: 55 mm
On structural steel: 40 mm
On masonry: 65 mm:
150 mm deep Hollowcore slab

Self weight of precast unit (without structural screed):  2.59 kN/m2
Concrete strength at service (28 days):  50 N/mm2
Concrete strength at transfer:  30 N/mm2
Prestressing strands: 7 wire 9.3 mm strand
Prestressing: 70% fpu
Maximum number of strands: 14
Cover to strand: 25 mm
Fire resistance (BS8110: Part 1:1997; Table 4.9): 1 hour
Minimum required effective bearing width (BS8110: Part 1:1997; Clause 5.2):
On concrete: 55 mm
On structural steel: 40 mm
On masonry: 65 mm:
250 mm deep Hollowcore slab

Self weight of precast unit (without structural screed): 3.59 kN/m2
Concrete strength at service (28 days):  50 N/mm2
Concrete strength at transfer: 30 N/mm2
Prestressing strands: 7 wire 9.3 mm strand fpu = 1700 N/mm2
Prestressing: 70% fpu
Maximum number of strands: 14
Cover to strand: 25 mm
Fire resistance (BS8110: Part 1:1997; Table 4.9): 1 hour
Minimum required effective bearing width (BS8110: Part 1:1997; Clause 5.2):
On concrete: 55 mm
On structural steel:  40 mm
On masonry: 65 mm
300 mm deep Hollowcore slab

Self weight of precast unit (without structural screed): 4.09 kN/m2
Concrete strength at service (28 days): 50 N/mm2
Concrete strength at transfer: 30 N/mm2
Prestressing strands: 7 wire 9.3 mm strand fpu = 1700 N/mm2
Prestressing: 70% fpu
Maximum number of strands: 14
Cover to strand: 25 mm
Fire resistance (BS8110: Part 1:1997; Table 4.9): 1 hour
Minimum required effective bearing width (BS8110 Part 1:1997; Clause 5.2):
On concrete: 55 mm
On structural steel: 40 mm
On masonry: 65 mm

SOUND RESISTANT FLOOR SLABS

O’Reilly Concrete Hollowcore floor units have a high resistance to both airborne noises and impact sounds. Because our cores are made using polystyrene formers, our units are also the perfect acoustic barrier between floors such as in apartment buildings.Acoustic Hollowcore 150

hollowcore-150mass per m2 without screed: 3o0 kg/m2
mass per m2 with 75 mm screed: 490 kg/m2

Acoustic Hollowcore 200

hollowcore floor-200

mass per m2 without screed: 370 kg/m2
mass per m2 with 75 mm screed: 460 kg/m2

Acoustic Hollowcore 250

hollowcore floor-250 mass per m2 without screed: 415 kg/m2
mass per m2 with 75 mm screed:605 kg/m2

BETTER THERMAL PROPERTIES
O’Reilly pre-stressed Hollowcore floor units have better thermal properties than slabs with open hollow voids due to completely closed cores filled with polystyrene. The air movement in traditional hollowcore slabs reduces their thermal performance. The thermal performance of standard O’Reilly Hollowcore floor slabs is 25% better in average com- paring to the same slabs with open voids.

THERMAL MASS EFFECT
Thermal mass is a property that enables precast concrete floors to absorb, store, and later release significant amounts of heat. Buildings constructed of concrete and masonry have a unique energy-saving advantage because of their inherent thermal mass.

Below is a comparison of U-value between our standard Hollowcore slabs and the same slabs with open voids; lover U-value means better thermal insulation:

Slab Depth U-value U-value
for O’Reilly standard Hollowcore slab for the same slab with open voids
150 mm Hollowcore 1.719 2.449
200 mm Hollowcore 1.481 2.003
250 mm Hollowcore 1.317 1.722
300 mm Hollowcore 1.192 1.522

The thermal performance of standard O’Reilly Hollowcore floor slabs is 25% better in average comparing to the same slabs with open voids