STANDARDS FOR AGGREGATES
Aggregates and test methods. These new Standards will change the way in which we look at our aggregates, although the materials will be the same there is a new way of defining aggregate sizes, different sieve sizes with new grading and a new set of tests for physical and mechanical properties.
AGGREGATE SIZE (d/D)
Sizes are now described using two sieves a lower sized sieve (“d”) and a higher size sieve (“D”) and is now classed as d/D, an old 20mm single size stone will now be classed as 10/20 e.g. “d” equals a 10mm sieve and “D” equals a 20mm sieve. For all-in aggregates “d” is 0.
BS 63 New EN
Size Size
40mm 20/40
28mm 20/32
20mm 10/20
14mm 6.3/14
10mm 4/10
6mm 2/6.3
3mm 1/4
CRF 0/4 all-in
Fine Sand 0/2FP
GRADING CATEGORY (Gc)
There is now a Grading Category (Gc) which specifies the percentage of material passing d/D, therefore a 10/20 would have a grading category Gc85/20 this means that up to 85% of the material can pass the 20mm sieve (D) and up to 20% can pass the 10mm sieve (d).
The grading for a 10/20 Gc85/20 would be
Sieve Size Percentage Passing
40mm 100
31.5mm 98 – 100
20mm 85 – 99
10mm 0 – 20
4mm 0 – 4
FLAKINESS (FI)
The Flakiness test has changed you now use a bar sieve along with the new sieve sizes, the results are lower then the old method and for Asphalts a Flakiness of less then 35 is now acceptable FI35. |
