AS 1012.8.4:2015 pdf free.Methods of testing concrete Method 8.4: Method for making and curing concrete- -Drying shrinkage specimens prepared in the field or in the laboratory.
4 ArPARATUS
The following apparatus shall be used.
4.1 Moulds
4.1.1 General
Moulds shall be made of non-absorbent material which does not react with cement paste and their internal surfaces shall have a smooth finish. The moulds shall be substantial enough to hold their form without distortion and shall he substantially leak-proof.
Each mould shall be provided with a base plate 10 which two end plates are securely fastened by screws, two side plates which are fastened to the end plates by screws, and two partially loose end plates which act as gauge stud holders. Each gauge stud holder shall fit inside the end of the mould and shall locate and secure a gauge stud during the seuing period of the concrete. Each gauge stud holder shall be held in position against the end plate by a retaining screw and shall he capable of release after compaction of the concrete. The opposite side plates shall he parallel and the distance between them shall be 75 ±1 mm. The inside height shall be 75 ±1 mm.
4.1.2 (‘onsiruction of ihe mould
The construction of the mould shall be aligned coaxially along the central axis of the n1oulded specimen, with the distance between the inner ends of the two studs being 250 ±0.5 mm, and that between the outer ends 295 ±1 mm. Gauge studs shall protrude from the gauge stud holders to a distance of 15 ±1 mm. A suitable form of construction of the moulds is shown in Figure I.
4.2 Gauge studs
Gauge studs shall he of stainless steel and shall comply with the dimensions shown in Figure 2. The radius of the gauge stud end shall be as follows:
(a) Horizontal comparator approximately 150 mm.
(h) Vertical comparator approximately 5 mm.
Gauge studs for horizontal and vertical comparators shall not be interchanged.
NOTE: As gauge studs are not interchangeable. ii is recommended that the preparing laboratory confirm that the proposed gauge studs are compatible with the measuring laboratory’s equipment.
4.3 Length gauge
A length gauge shall he provided for checking the nominal length between gauge studs. The length gauge shall be made of metal and shall have a diameter of at least 6mm and a length of 250 ±0.2 mm. The ends of the bar shall be flat and perpendicular to its length.
4.4 Tamping bar (hand compaction)
The bar used for compacting concrete in the moulds shall be a straight metal rectangular bar having nominal dimensions of 25 mm x 10mm x 300 mm long with a ramming face square with the axis.AS 1012.8.4 pdf download.