ABSTRACT
The specimens shall be made as soon as practicable after sampling but not later than 1 hr after addition of the water to the mix. The mould shall be filled to about half height with mortar and the layer of mortar compacted by ramming it with the compacting bar in a unform manner over the mortar with neither segregation nor excessive laitance. The number of strokes of the compacting bar to produce this specified condition will vary according to the consistence of the mortar but in no case shall less than 25 strokes be given. The mould shall then be overfilled with more mortar and this layer compacted as before. The surface shall be struck off plane and level with the top of the mould using the palette knife or trowel. The mould shall be cured in moist conditions e.g. placed in a sealed plastic bag or a 100% humidity chamber at a temperature of 20 ±2°C for one to three days depending on the early strength of the mortar. The specimens shall then be demoulded without damage marked for later identification and immediately transferred to the appropriate conditions for subsequent curing.
