What is “No Fines” Concrete?
However, blended aggregates (10 and 7mm; and 20 and 14mm) have been found to perform satisfactorily. Because it is characterized by uniformly distributed voids, it is not suitable for reinforced or prestressed concrete construction.
- Walls in buildings: Primarily in external and internal walls of low-rise and multi-storey flats/units.
- Car park paving: Provides free-draining pavements for light traffic
- Tennis courts: Using a small nominal aggregate size, e.g. 5mm, a free-draining playing surface is achieved.
- Drainage layers: Used as drainage layers on civil engineering projects. 20-mm aggregate size is preferred but the surface finish is poorer than that achieved using 10-mm aggregate.
- Levelling courses: Has been used as a lightweight screed for levelling on floors and roofs.
- Compressive Strength: This is lower than conventional concrete and is a function of the aggregate: cement ratio, the water-cement ratio, and the degree of compaction (the density). Typical strengths are in the range 5 to 13 MPa. A mix with an aggregate: cement ratio of 8:1; a water-cement ratio of 0.4; and a density of1850kg/m3has strength of approximately 7.5 MPa.
- Drying Shrinkage: Much lower than conventional concrete, e.g. in range 0.0002–0.0003 microstrain.
- Permeability: High. Water and air flow easily through it but no quantitative data is available. As noted above, blocking of the pores is more likely to occur the smaller the aggregate size.