A number of advantages

SCC with lightweight aggregates

[Foto: Argex]

Fig. 1 Defintion of empirical reference curves based on the results with theoretical curves for granule distribution.

[Foto: Argex]

Fig. 2 Required criteria and their testing methods.

Fig. 3a and b Checking of the slump flow (left) and the L-box ratio (right).

Fig. 4 Relation between characteristic compressive strength and dry density.

Fig. 5 Light-weight SCC is
often used for large wall
panels.

The need to reduce the dead weight of building structures and to reduce transport costs has resulted in an increasing demand for light-weight Argex concrete. This concrete is used especially for renovating floors, for new structures equipped with foundations of lower load-bearing capacity, and precast wall and floor sections. The Argex lightweight concrete results in a number of some further advantages when compared to standardweight concrete: good fire resistance due to the fire-proof nature of Argex partic-les and increased heat insulation due to their open structure. Together with the benefits of self-compacting concrete, the combination of these properties offers great opportunities for the precast industry, which is already producing a large proportion of sections in self-compacting concrete.

Self-compacting concrete can be processed purely under the impact of gravity and without any vibration, even in densely reinforced false work or complex geometries. For this purpose, the concrete must be highly fluid and the mixture must be sufficiently stable to prevent segregation.

If manufacturers of precast components wish to incorporate self-compacting light-weight concrete into their production process, they will have to take into account a number of practical issues that are associated with the application of lightweight aggregates, such as the water absorption of the particles,...