Lightweight aggregates

In the UK the most commonly used lightweight aggregate is LYTAG, a sintered fly ash, also known as pulverised fuel ash (pfa). Other aggregates, made from a variety of raw materials, are shown in the Table below.

Aggregate type	Trade name	Dry density kg/m3
Furnace clinker		720-1040
Processed fly ash/pfa	Lytag	770-960
Foamed blastfurnace slag		670-920
Expanded clay, shale and slate	Aglite, Leca, Solite	320-960
Pumice		480-880
Pelletized expanded slag	Pellite	800-1000
Wood and plastic particles		320-480
Expanded vermiculite		60-160

The density of the resulting concrete will depend on the type of aggregate used. Lightweight aggregates may be used for the coarse aggregate in conjunction with natural fines, or lightweight can be used for both coarse and fine aggregates.

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