Large Lightweight Precast Concrete Panels of Industrial Hall with improved thermal insulation properties.
CONCRETAN was awarded the design and pilot production of large precast lightweight self-compacted concrete Panels of Industrial Buildings. The requirement was the combination of the satisfaction of structural criteria with the minimisation of self-weight and maximisation of thermal insulation properties.
The size of the panels was:
- Length =7.50-12.50 m
- Height =2.40-3.00 m
- Thickness=0.16-0.020 m
We designed three types of the above Panels and pilot manufactured two of them. The following:
- 00 x 2.40 x 0.20 m -Mix-1
- 50 x 3.00 x 0.16 m -Mix-2
The Panels were cast in Production Hall of cooperating Precast Concrete Company. The ambient Temperature in the casting hall was varying between 5 to 10 ο C and the walls were steam cured with maxιmum Temperature 55 ο C for 3 hours.
Then, after the completion of curing, they were struck off the moulds and exhibit at 15 hours:
- Mix-1: compressive strength fcc=21.9 MPa- density =1777 kg/m3
- Mix -2: compressive strength fcc=26.2MPa- density =1807 kg/m3
The corresponding values at 28 days were found as follows:
- Mix-1: compressive strength fcc=34.0 MPa- density =1650 kg/m3-and corresponding thermal conductivity coefficient λ= 0.57 W/mK
- Mix -2: compressive strength fcc=38.1 MPa- density =1757 kg/m3 -and corresponding thermal conductivity coefficient λ= 0.65 W/mK
Above data, compared to the respective ones of Normal Weight Concrete (which has λ=1.44 W/mK } show:
- Reduction in self-weight: 33 % – 28 % and
Improvement of thermal insulation properties: 252 % – 228 % correspondingly.
