AS 1012.5:2014 pdf free
AS 1012.5:2014 pdf free.Methods of testing concrete Method 5: Determination of mass per unit volume of freshly mixed concrete
Compaction by hand shall be carried out as follows:
(a) Fill the measure in three approximately equal layers with the scoop. As each scoopful of concrete is being placed into the measure, move the scoop around the top edge of the measure as the concrete slides out, to ensure symmetrical distribution of the concrete within the measure.
(b) Fully compact each layer by rodding. Rod the bottom layer throughout its depth. For each upper layer, just penetrate into the underlying layer with at least the first 10 strokes.
NOTE: The minimum number of strokes per layer required to compact average concretes with different consistencies is set out as a guide for 250 mm diameter measures in Table 1. For slumps of less than 40 mm, refer to AS 1012.8.1.
Compaction by vibration shall be carried out as follows:
(a) Fill the measure in two approximately equal layers with the scoop. As each scoopful of concrete is being placed in the measure, move the scoop around the top edge of the measure as the concrete slides out, to ensure symmetrical distribution of concrete.
(b) Place all the concrete for each layer before commencing vibration.
(c) Vibrate each layer only long enough to achieve full compaction.
NOTE: The duration of vibration required to compact each layer will depend upon the workability of the concrete and the effectiveness of the vibrator. Usually the surface of the concrete becomes relatively smooth in appearance and substantial air bubbles cease breaking the surface when sufficient vibration has been applied. Extreme care should be taken to avoid segregation when using vibration to compact concrete with slump greater than 100 mm.
(d) Where an internal vibrator is used, compact each layer by four insertions of the vibrator at points symmetrically distributed over the cross-section of the measure. Do not allow the vibrator to rest on the bottom of the measure or to touch the sides of the measure. Take care to withdraw the vibrator in such a manner that no air pockets are left in the specimen. After vibrating the top layer, tap the sides of the measure sharply 10 to 15 times with the mallet.AS 1012.5 pdf free.
