1. GRADING & RELATED ISSUES WORKSHOP : AGGREGATES
DEFINING THE ISSUES
5 FEBRUARY 2014

2. Outline
Background
Defining the issues

3. Background
Revision of the TMH1 - financed by SANRAL and carried out under the auspices of the Materials Testing Committee (MTC) of the Road Materials Committee (RMC).
The revision of TMH1 to SANS3001 necessitated the use of new sieve sizes according to ISO Standards
The grading envelope (spec) was not changed in an attempt not to affect the outcome of test results as a grace period was allowed for labs to still use THM1 sieves

4. Defining the Issues
Continuous graded aggregate mixes not affected by implementation of new sieve sizes for grading analysis
New grading limits determined through interpolation
Example of new specifications according to SANS3001

5. New Grading Spec for Asphalt

6. Defining the Issues
Single-sized aggregate was affected by implementation of new sieve sizes for grading analysis
New grading limits determined through interpolation, BUT
Resulted in stricter specifications in order to maintain the same grading envelope as for TMH1
Example of new specifications according to SANS3001

7. New Grading Spec for Single Sized Aggregate

8. Proposed Solution
Single-sized aggregate: TMH1 envelope to be applied for SANS3001 sieves

9. Impact of proposed changes
Slightly higher ALD’s which is more beneficial for surfacing seals as it allows for higher binder applications
Less material wastage

10. Questions