Precast Hollow Core
Hollow core structure is a typical precast building piece for ceilings. Prefabrication of this structure makes its production very fast. There is no need for formwork and therefore the cost is reduced. Also there is no need for jacking during the ceiling construction, which makes partitioning possible immediately after hollow cores are installed.
Since hollow core is pre-stressed and is relatively thin, it is strong enough to be used for up to 18 m span. In such ceiling thermal rebar covers its surface with a thin concrete layer after hollow core pieces are installed.
Perlite commissioned its hollow core production unit with 11 production lines in the year 2012. Perlite purchased modern hollow core production equipment and their operating system from Elematic Co. (Finland), a well-known world manufacturer of hollow core equipment.
Nominal production rate of this unit is 2000 m^2 per day and it reached 45000 m^2 per month in the first phase of Iran Mall Construction project. Perlite Produced and Installed about 247000 m^2 of hollow core in the first phase of Iran Mall project and 135000 m^2 in the second phase. These pieces have 250,300 and 400mm thickness which are suitable for 10m, 12m and 16m spans, respectively.
14 hour strength of hollow core pieces is 30 mega Pascal and final strength in 28 days is 45 mega Pascal. This is due to special mix design and zero slump concrete used.
Advantages of hollow core:
- Low cost
- High loading capacity
- Quick installation without need for scaffolding
- Saving in consumable material
- Fireproof property
- High quality and durability
- Use of hollow space inside the structure as mechanical/electrical ducts
- Fast and simple production
- Flexibility in design
- Insulation for heat and sound