What is DSP concrete?
DSP stands for Densified Small Particles and refers to an ultra-high-performance concrete in which ultra-fine particles such as silica fume make the material extremely dense and strong. Compressive strengths of 150 to 400 N/mm² are achievable, several times that of ordinary structural concrete, and the material is used where peak performance is needed in a small volume.
How does DSP concrete work?
Ordinary concrete contains relatively coarse sand and cement particles. Small pores between them weaken the material. In DSP concrete, silica fume (micro-silica) is added: very fine, spherical particles that fill the pores. The result is a much denser packing.
Other characteristics:
- Low water-cement ratio — superplasticisers allow lots of cement with little water
- Optimised grading — particle sizes from millimetre to nanometre
- Often steel fibres — for tensile capacity and ductile behaviour
- High compressive strength — up to 400 N/mm²
- Low permeability — resistant to aggressive environments
Application
- Slender precast units — facade panels, columns and beams
- Bridges — thin decks and tall pylons with long spans
- Heavy industrial floors — for extreme loading
- Repair concrete — for high-strength local repairs
- Architectural details — fine profiles and ornaments
Points of attention
- DSP concrete is expensive and needs specialist processing
- Mixing takes longer than normal concrete; use a powerful mixer
- Bonding to a substrate requires preparation
- Shrinkage can be greater than in normal concrete — careful curing
- Combination with conventional reinforcement requires adapted detailing
Related terms
- Structural concrete
- Concrete type
- Compressive strength
- Concrete quality
- Concrete mortar
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