ISO 20290-3:2019
(Main)Aggregates for concrete — Test methods for mechanical and physical properties — Part 3: Determination of aggregate crushing value (ACV)
Aggregates for concrete — Test methods for mechanical and physical properties — Part 3: Determination of aggregate crushing value (ACV)
This document gives the determination of aggregate crushing value (ACV) of aggregates. This gives a relative measure of the resistance of the aggregate crushing under the gradually applied compressive load. The method is applicable to aggregates passing a 14,0 mm test sieve and retained on a 10,0 mm test sieve. For other size fractions, a recommended method is described in Annex A. The aggregate size fraction taken for this test can also be as per the relevant national standards. NOTE Minor variations in grading divisions can be allowed in respective national standards. The method is not suitable for testing aggregates with an aggregate crushing value higher than 30. In such cases, the method described in ISO 20290-4 is applicable.
Granulats pour béton — Méthodes d'essai relatives aux propriétés mécaniques et physiques — Partie 3: Détermination de la valeur de concassage des granulats (ACV)
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Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 20290-3
First edition
2019-11
Aggregates for concrete — Test
methods for mechanical and physical
properties —
Part 3:
Determination of aggregate crushing
value (ACV)
Granulats pour béton — Méthodes d'essai relatives aux propriétés
mécaniques et physiques —
Partie 3: Partie 3: Détermination de la valeur de concassage des
granulats (ACV)
Reference number
©
ISO 2019
© ISO 2019
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ii © ISO 2019 – All rights reserved
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Sampling . 2
6 Apparatus . 2
7 Preparation of test portions and specimens . 4
7.1 Test portions . 4
7.2 Preparation of test specimens . 4
8 Procedure. 5
9 Calculation and expression of results . 5
10 Test report . 6
Annex A (informative) Recommended method for determining the aggregate crushing
value for other size fractions of aggregate . 7
Foreword
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different types of ISO documents should be noted. This document was drafted in accordance with the
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iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 71, Concrete, reinforced concrete and pre-
stressed concrete, Subcommittee SC 1, Test methods for concrete.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
A list of all parts in the ISO 20290 series can be found on the ISO website.
iv © ISO 2019 – All rights reserved
INTERNATIONAL STANDARD ISO 20290-3:2019(E)
Aggregates for concrete — Test methods for mechanical
and physical properties —
Part 3:
Determination of aggregate crushing value (ACV)
1 Scope
This document gives the determination of aggregate crushing value (ACV) of aggregates. This
gives a relative measure of the resistance of the aggregate crushing under the gradually applied
compressive load.
The method is applicable to aggregates passing a 14,0 mm test sieve and retained on a 10,0 mm test
sieve. For other size fractions, a recommended method is described in Annex A. The aggregate size
fraction taken for this test can also be as per the relevant national standards.
NOTE Minor variations in grading divisions can be allowed in respective national standards.
The method is not suitable for testing aggregates with an aggregate crushing value higher than 30. In
such cases, the method described in ISO 20290-4 is applicable.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 565, Test sieves — Metal wire cloth, perforated metal plate and electroformed sheet — Nominal sizes
of openings
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
aggregate crushing value
ACV
percentage to the first decimal place, of the mass of fines formed to the total mass of the test specimen
4 Principle
A test sample of aggregates is compacted in a specified manner into a steel cylinder fitted with a freely
moving plunger. The sample is then subjected to a standard loading regime applied through the plunger.
This action crushes the aggregate to a degree which is dependent on the crushing resistance of the
material, which is assessed by a sieving test on the crushed specimen and is taken as a measure of the ACV.
5 Sampling
The sample used for the test (the laboratory sample) shall be as per Clause 7.
NOTE National standards can also exist regarding the sampling.
6 Apparatus
6.1 Compression testing machine, capable of applying any force up to 500 kN and which can be
operated to give a uniform rate of loading so that the required force (400 kN) is reached in 10 min
(see 8.2).
NOTE National standards can also exist regarding the requirements of the compression testing machine.
6.2 Steel cylinder and plunger, with an open-ended steel cylinder of nominal 150 mm internal
diameter and with plunger and base plate as per Figure 1 and Table 1.
Table 1 — Principal dimensions of cylinder and plunger apparatus
Component Dimensions (see Figure 1) Nominal 150 mm Nominal 75 mm internal
internal dimeter of diameter of cylinder
cylinder
(see Annex A)
mm
mm
Cylinder Internal diameter, D 154 ± 0,5 78,0 ± 0,5
c
Internal depth, h 125 to 140 70,0 to 85,0
c
Minimum wall thickness, d 16,0 8,0
c
Plunger Diameter of piston, D 152 ± 0,5 76,0 ± 0,5
p
Diameter of stem, D >95 to ≤D >45 to ≤D
s p p
Overall length of piston plus stem, L 100 to 115 60,0 to 80,0
p
Minimum depth of piston, h not less than 25,0 not less than 19,0
p
Diameter of hole, D 20,0 ± 0,1 10,0 ± 0,1
h
Baseplate Minimum thickness, d 10 10
b
Length of each side of square, L 200 to 230 110 to 115
b
2 © ISO 2019 – All rights reserved
NOTE See Table 1.
Figure 1 — Outline form of cylinder and plunger for aggregate crushing value test.
The surfaces in contact with the aggregate shall be machined and maintained in a smooth condition
and preferably case hardened.
6.3 Tamping rod, made out of straight iron or steel bar of circular cross-section, diameter of
(16 ± 1) mm and (600 ± 5) mm long, with both end semi-spherical.
6.4 Balance, of at least 3 kg capacity, readable to 1 g.
6.5 Cylindrical metal measure, for measuring the sample, of sufficient rigidity to retain its form under
rough usage and having an internal diameter of (115 ± 1) mm and an internal depth of (180 ± 1) mm.
6.6 Test sieves, with square-hole perforated plate of sizes 14,0 mm and 10,0 mm and a woven wire
2,36 mm test sieve. The test sieves shall comply with ISO 565 or relevant national standards.
6.7 Well-ventilated oven, thermostatically controlled at a temperature of (105 ± 5) °C.
6.8 Metal tray, of known mass large enough to contain 3 kg of aggregate.
6.9 Rubber mallet, of suitable handle and minimum weight of 400 g.
6.10 Brush, with stiff bristles.
NOTE Minor variations in apparatus’ ranges/dimensions can be allowed in respective national standards.
7 Preparation of test portions and specimens
7.1 Test portions
Reduce the laboratory sample to produce a test portion of sufficient mass to produce three test
specimens of 14 mm to 10 mm size fraction.
NOTE A single test specimen is that quantity of material required to fill the cylinder (see 8.1 and Table 2).
Table 2 — Guide to minimum mass of test portions required to obtain a suitable mass of
material to determine the ten percent fines value
Grading of the aggregate Minimum mass of the test
a
portion
mm
kg
All-in aggregate 40 max. size 60
All-in aggregate 20 max. size 45
Graded aggregate 40 to 5 40
Graded aggregate 20 to 5 25
Graded aggregate 14 to 5 15
a
For normal density aggregates.
NOTE In case of single size aggregates being supplied for the test, the minimum mass of the test portion can
vary accordingly.
7.2 Preparation of test specimens
7.2.1 Thoroughly sieve the entire surface dry test portion on the 14 mm and 10 mm test sieves to
remove the oversize and undersize fractions. Divide the resulting 14 mm to 10 mm fraction to produce
three test specimens each of mass such that the depth of the material in the cylinder is approximately
100 mm after tamping as described in 7.1 (see Note).
NOTE The appropriate quantity of aggregate can be found conveniently by filling the cylindrical measure
in three layers of approximately equal depth. Tamp each layer 25 times, from a height of approximately 50 mm
above the surface of the aggregate, with the rounded end of the tamping rod. Level off using the tamping rod as a
straight edge.
7.2.2 Dry the test specimens by heating at a temperature of (105 ± 5) °C for a period of not more than
4 h. Cool to room temperature before testing. For temperature-sensitive recycled aggregates, a drying
temperature of (40 ± 5) °C shall be used. Record the mass of material comprising the test specimens
before testing.
4 © ISO 2019 – All rights reserved
8 Procedure
8.1 Place the cylinder of the test apparatus in position on the baseplate and add the test specimen
in three layers, each layer being subjected to 25 strokes of the tamping rod distributed evenly over the
surface of the layer and dropping from a height approximately 50 mm above the surface of the aggregate.
Carefully level the surface of the aggregate and insert the plunger so that it rests horizontally on this
surface. Take care to ensure that the plunger does not jam in the cylinder.
8.2 Place the apparatus, with the test specimen prepared as described in 7.2 and plunger in position,
between the platens of the compression testing machine and load it at as uniform a rate as possible (see
Note) so that the required force of 400 kN is reached in 10 min ± 30 s.
When, during the early stages of the test, there is a significant deformation, it may not be possible
to maintain the required loadin
...
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