MATERIALS SPECIFICATIONS
Sub 100 or GAP 100, Blue/Brown Rock
Blue/Brown Rock is a nonspecific rock aggregate intended for use as a shape correction or
subgrade improvement layer below the designed pavement.
The minimum requirements are:
98% of the material shall be less than 100mm maximum size with greater than 15%
passing a 1.18mm sieve.
The minimum crushing resistance shall be 80kN (NZS 4407:1991: test 3.10)
10% of the dry mass shall be unweathered (Blue) stone
A minimum soaked CBR Strength of 20 (NZS 4407:1991: test 3.15)
Depending on the properties of the material proposed the Engineer at his discretion may
approve Blue/Brown material for use as a lower Sub-base layer.
GAP 65 Aggregate
GAP 65 aggregate shall comprise crushed aggregate and be free from all non-mineral matter
with the following requirements:
Crushing resistance minimum 90kN (NZS 4407:1991: test 3.10)
A minimum soaked CBR Strength of 40 (NZS 4407:1991: test 3.15)
Grading (NZS 4407:1991: test 3.8.1)
GAP 65 Subbase AGGREGATE Limits
Sieve size (mm)
% Passing
63.00
100
19.00
40
65
0.30
0
10
GAP 40 Base Course Pavement Aggregate
The Base Course Pavement material shall comply with the following requirements:
Crushing resistance 120kN (NZS 4407:1991: test 3.10)
Plasticity Index Range 5 – 10 (NZS 4407:1991: test 3.4)
A maximum Clay Index of 6 (NZS 4407:1991: test 3.5)
Grading (NZS 4407:1991: test 3.8.1)
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GAP 40 Pavement Aggregate Limits
Sieve size (mm)
% Passing
37.50
100
100
26.50
80
90
19.00
60
81
9.50
46
63
4.75
34
50
2.36
27
41
1.18
22
34
0.425
16
26
0.30
14
24
0.075
7
17
Note: Clay content is required to be regulated to produce the Plasticity Index of between 5 and
10, and a Liquid Limit of between 25 and 35.
AP 30 Wearing Course Aggregate
Wearing Course shall be a well graded crushed or screened aggregate that binds into a tightly
compacted knitted mosaic surface under the action of rolling and complies with the following
requirements:
Shrinkage Product (SP) of between 100 and 365 (240 preferred)
Grading Coefficient (GC) of between 16 and 34
Grading (NZS 4407:1991: test 3.8.1)
AP 30 Wearing Course Limits
Sieve size (mm)
% Passing
37.50
100
26.50
100
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19.00
90
100
9.50
65
90
4.75
55
85
2.36
40
70
0.425
25
45
0.075
10
25
Where; Shrinkage Product (SP) = Linear Shrinkage x % Passing 0.425mm and Grading Coefficient
(GC) = (% passing 26.50mm - % passing 2.0mm) x % passing 4.75mm/100 (NZS 4402:1986: Test
2.6 Determination of the Linear Shrinkage)
Note: The New Zealand Standards for “Methods of Sampling and Testing Road Aggregates” (NZS
4407:1991) was reviewed and updated in 2015. NZS 4407:1991 will be superseded by NZS
4407:2015, this process is still in the transitional stage with the previous standards being
phased out over time. We acknowledge there are new standards, but have quoted the older.
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