Heavyweight concrete is mainly used for radiation protection. The critical properties of a heavyweight concrete are:
- Homogeneous density and spatial closeness of the concrete
- Free from cracks and honeycombing
- Compressive strength is often only a secondary criterion due to the large size of the structure
- As free from air voids as possible
- Keep shrinkage low
Composition
- Aggregate
– Use of barytes, iron ore, heavy metal slags, ferrosilicon, steel granules or shot
- Cement
– Allow for hydration heat development when selecting the cement type and content
- Water content
– Aim for a low water/cement ratio
- Workability
– To ensure a fully closed concrete matrix, careful consideration should be given to the placing (compaction).
- Curing
– Allowance must be made in the curing method for the high heat develop-ment due to the likely large mass of the structure.