AS 3583.6:2018 pdf free download – Methods of test for supplementary cementitiousmaterials Method 6: Determination of relative water requirement and strength index

AS 3583.6:2018 pdf free download – Methods of test for supplementary cementitiousmaterials Method 6: Determination of relative water requirement and strength index.
7 PREPARATION
7.1 General
In the determination of relative water requirement and strength index, results for the test mortar are related to results for the control mortar. It is therefore necessary to prepare a control mortar on each day that one or more test mortars are prepared.
7.2 Control mortar
A batch of control mortar shall consist of 450 ±2 g of cement, 1350 ±2 g of sand and sufflcient water to achieve a flow of 110 ±5% when determined in accordance with AS 2701 (nominally 210 g water).
7.3 Test mortar
Slag and fly ash shall be prepared in accordance with Table 1.
A batch of test mortar shall consist of the quantities of Type GP cement and a test sample of slag or fly ash as shown in Table 1, 1350 ±2 g of standard sand, and sufficient water to achieve a flow within ±3 units of the flow recorded for the control mix.
(b) Measure the flow of the mortar as described in AS 2701. If the flow is not within the range 110 ±5%, the mortar shall be discarded and a new batch prepared with an adjusted water content.
(c) Provided the flow is in the range 110 ±5%, record the mass of water used and the flow.
(d) Discard the mortar batch used to determine the flow.
8.3 Test mortar
The procedure shall be as follows:
(a) Mix the batch of mortar as described in AS 2350.12.
(b) Measure the flow of the mortar as described in AS 2701. If the flow is not within three units of the flow recorded for the control mortar, the mortar shall be discarded and a new batch prepared with an adjusted water content.
(c) Provided the flow is within three units of the figure recorded for the control mortar, record the mass of water used and the flow.
(d) Discard the mortar batch used to determine the flow.
8.4 Strength index specimens
The procedure shall be as follows:
(a) Prepare, mix and cure each set of three specimens as described in AS/NZ 2350.11 and AS 2350.12, using the water contents determined in Clauses 8.2 and 8.3 above.
(b) Demould each set of specimens as described in ASINZ 2350.11.
(c) For a standard test, cure the specimens in lime saturated water at 23 ±2°C, as described in AS/NZ 2350.11, before testing at an age of 28 days (see Note 1).
(d) For an accelerated test, after initial 24 h curing in the humidity cabinet, cure the
specimens in lime saturated water at 23 ±2°C, as described in AS/NZS 2350.11 for
4 days ±1 h. Remove and immerse the specimens in a water bath at 50 ±1°C for
46 h ±0.5 h. Remove and condition the specimen in water at 23 ±2°C for 2 h ±0.25 h
before testing at age seven days (see Note 2).
NOTES:
I Caution should be exercised when attempting to correlate results between 28 day and 7 day (accelerated) results. Where possible, 28 day results should be used they are more reliable.
2 Specimens from both the control mortar and the test mortar should be subjected to the same curing regime.
8.5 Compressive strength testing
The procedure shall be as follows:
(a) Determine the compressive strength of a set of specimens as described in
AS/NZS 2350.11.
(b) Record the mean compressive strength for each set of specimens.
9 CALCULATION
9.1 Relative water requirement
The following calculations shall be made:
(a) Slag samples The relative water requirement is calculated as follows.