ISO 1920-13:2018 download free.Testing of concrete Part 13 : Properties of fresh self compacting concrete.
This test specifies the procedure for determining the slump-flow and t5o time for self-compacting concrete. The test is not suitable when the maximum size nithe aggregate exceeds 40 mm.
4.2 Principle
The slump-flow test is an indication of the Ilowability of self-compacting concrete in the absence of obstructions. It is based Ofl the slump test described in Iso 1920-2. The flowability is evaluated by measuring the spreading maximum diameter, dmax, and the time it reaches the spreading diameter of 500 mm, t500. The d,ax of spreading is a measure of the self-compacting concrete flow range when subjected to load from its own weight. It is an indication of the yield stress of the self-compacting concrete. The t500 time is a measure of the speed of flow and an indication of the relative viscosity of the self-compacting concrete, The result is an indication of the filling ability of self-compacting concrete.
The fresh concrete is poured into a cone as specified for the ISO 1920-2 slump test. When the cone is withdrawn upwards, the time from commencing upward movement of the cone to when the concrete has flowed to a diameter of 500 mm is measured; this is the t500 time. The largest diameter of the flow spread of the concrete and the diameter of the spread at right angles to it are then measured and the mean is the slump-flow.
4.3 Apparatus
4.3.1 Mould, in accordance with ISO 1920-2:2016, 4.3.2.1 (see Figure 1).
4.3.2 Rule or measuring tape, of minimum length 1 000 mm and having sub-divisions not greater than 5 mm along its entire length.
4.3.3 Stop watch, capable of measuring to 0,1 s.
4.3.4 Spirit level, for checking horizontality of base plate prior to commencing the test.
4.35 Container, to hold the test sample and having a volume of at least 10 .
6.4 Test sample
A sample of at least 14 I shall be obtained in accordance with Iso 1920-1.
6.5 Test procedure
Support the L box on a level base and check for horizontality using the spirit level. Clean the L box and dampen immediately prior to testing, but keep free from excess moisture. Close the gate between the vertical and horizontal sections. Pour the concrete from the container(s) into the filling hopper of the L box, without any agitation or mechanical compaction, then strike off the top with the straight edge so that the concrete is levelled with the top of the vertical section of the L box and allow to stand for (60 ± 10) s.
Check the concrete for signs of segregation before and after filling of the I box and report under 6.6. d) in a qualitative way (e.g. no indication of segregation, strong indication of segregation).
NOTE Signs of segregation include a layer of cement paste/mortar and segregated coarse aggregate at the top.
Fully open the sliding gate in a smooth continuous action to allow the concrete to flow into the horizontal section. When movement has ceased, measure the drop in height of the level of concrete, AH1, to the nearest 1 mm in the vertical section on the gate side of the box at three positions equally spaced across the width of the box. The mean depth of the concrete, H1. is the difference between the height of vertical section and the average of the three readings ofH1. Record H1 to the nearest 1 mm. The same procedure is used to calculate the mean depth of the concrete at the end of the horizontal section of the L box, H2, from the difference with the height of the horizontal section and the average of the three readings of tH2. Record H2 to the nearest 1 mm.
6.6 Test result
The passing ability ratio, PL, as measured by the L box test, is calculated to the nearest 0,01 from Formula (2):
The method follows the procedure detailed in Clause 4 except that, before filling the mould (slump cone) with concrete, the J-ring, consisting of a ring of evenly spaced vertical smooth bars, is placed over the cone.
In addition, the time when the concrete has flowed to a diameter of 500 mm too shall be measured, when specified.
I-rings specified in national standards may be used where applicable.
8.3 Apparatus
The apparatus shall be in accordance with Clause 4 with the following additional items.
NOTE The feet to the slump cone can be removed to fit inside the I-ring or if their presence prevents free upward movement from within the J-ring.
8.3.1 Narrow gap J-rlng, with smooth steel bars, (18 ± 0,5) mm diameter, secured to a ring (300 ± 2) mm diameter (bar spacing of(41 ± 1) mm) with the dimensions as shown in Figures 8 and 9.
8.3.2 Wide gap i-ring, with smooth steel bars, (18 ± 0,5) mm diameter, secured to a ring (300 ± 2) mm diameter (bar spacing of (59 ± 1) mm) with the dimensions as shown in Figures 8 and 10.
8.3.3 Straight edge, for aligning the reference line for the height measurements, with a length of about 400 mm.
any spilled concrete from the baseplate and ensure the baseplate is damp all over but without any surplus water.
Lift the cone vertically in 1 s to 3 s in one movement without interfering with the flow of concrete. lithe tsoo, time has been requested, start the stop watch immediately the cone ceases to be in contact with the baseplate and record the time taken to the nearest 0,1 s for the concrete to reach the 500 mm circle at any point.
Without disturbing the baseplate or concrete, measure the largest diameter of the flow spread and record as d1 to the nearest 10 mm. Then measure the diameter of the flow spread at right angles to d1 to the nearest 10 mm and record as d2 to the nearest 10 mm.
Lay the straight edge on the top side of the i-ring and measure the relative height differences between the lower edge of the straight edge and the concrete surface at the central position fh0 and at the four positions outside the J-ring, two h2 in the x-direction and the other two Ahi, 1h2 in the y-direction (perpendicular to x), as shown in Figures 9 and Iji measured to the nearest 1 mm,
Check the concrete spread for signs of segregation and report under 8, h) in a qualitative way, e.g. no indication of segregation, strong indication of segregation.
Calculate the difference between the slump flows with and without a I-ring (see Clause 4).
NOTE Signs of segregation include a ring of cement paste/mortar and segregated coarse aggregate in the central area.
8.6 Expression of results
8.6.1 Passing ability PJ
The J-ring passing ability, Pj, measured by the blocking step, is calculated using Furmu1a (4) and expressed to the nearest 1 mm.
NOTE 3 If a self-compacting concrete having a good Flowability through narrower spaces is used and if there is no friction between the concrete and the inside surfaces of the container, then the calculated heights of the concrete on the room B side at equilibrium between A and B are 365 mm and 335 mm in the containers shown in Figure ii. respectively. These shall be equal to the maximum fill heights of the testers, but the maximum fill height can slightly vary depending on the dimensional errors of the container, thickness of the partition board, and thickness of the partition gate. It is therefore advisable to confirm the maximum till height of the fill tester to be used by such methods as measuring the static water level in room B.
d) When the coarse aggregate content of concrete after passing through the obstacle is to be measured, the tester shall be of a structure having an openable sampling gateL4l on the room B side near the obstacle as shown In Figure 11.
NOTE 4 The coarse aggregate content Is not usually measured. However, in the case where a more precise judgment is required regarding passability through narrow spaces in placing without vibration compaction. the coarse aggregate content shall be measured using samples taken from near the obstacle after passing through the obstacle.
e) In addition to the fill tester, a container for pouring, such as a 5-litre plastic jug, a straightedge for striking off the top surface, measuring scale, stopwatch, damp cloth, etc., shall be prepared. The measuring scale to be used shall be measurable to I mm. The stopwatch shall be measurable to 0,1 s.