Review of TMH1

Tests on asphalt

Role of Sabita

• Motivation

• Standards

Motivation

• Industry expects realistic standards of:– material quality and – assessment thereof in a quality management process

(during process and acceptance control)

• Costs associated with inconsistent/incorrect testing - significant and wasteful

• Make a contribution to any effort that would advance consistency in production of test results used as a basis for judgement of compliance

International standards

• Sabita (& SABS) subscribes to WTO policy and obligations on government procurement:

“…technical specifications shall be based on international standards, where they exist…”

• Any deviations should be for compelling reasons• ASTM applied to assessment of bitumen quality

(SANS 307)• Currency of standards

– International standards are regularly reviewed and readily available

– TMH 1 last reviewed in 1986 (21years ago)

Process framework

• Sabita agreed to fund investigation into revision of TMH tests on asphalt

• Part of a more comprehensive process (interested parties, expert groups – MTC – SABS

• Convening of Sabita task team of experts• Elicit comments on SANS 3001 AS…• Collate comments • Submit to MTC (correct channels)

Sabita task team

• Composition

• Brief

• Investigation matrix

• Process

Task team composition

Henry Appollis (Much Asphalt)Wim Hofsink (PDNA)Tony Lewis (Iliso)Hennie Loots (SRT)Pieter Molenaar (SSI)Gert Mynhardt (Akasia)Wynand Nortje (National Asphalt)Francois Ruiters (More Asphalt)Gary Swart (BCP)Andre Ungerer (Goba)

Brief

• ASTM International selected as a benchmark standard

• Test methods (SANS 3001) to be subjected to comparative appraisal

• Comments and suggestions on the adoption of international standards

• Shape - a critical comparison of the methods proposed in SANS with ASTM standards

Investigation matrixCurrent TMH1

nomenclature

Scope of the test (not necessarily the

final title)

Proposed SANS test standard

ASTM

C2 Determination of Marshall stability and flow for bituminous mixtures

3001 – AS 2

D6927 - 06

Appendix to method C2

Preparation of briquettes for Marshall testing

3001 – AS 1

D6926 - 04

C3 Determination of the bulk relative density and void content of compacted asphalt

3001 – AS 10

D1188 - 96 D2726 - 05A

C4 (a) & (b) Determination of the maximum theoretical density and quantity of binder absorbed by the aggregate

3001 – AS 11

D2041 - 03A

C7 (a) (b) & (c)

Determination of the binder content of a bituminous mixture

3001 – AS 20

D2172 – 05 D4125 – 05 D6307 - 05

Summary of comments

• Brevity and incompleteness of AS methods

• ASTM Int. by far more comprehensive - constitutes a standard (rigorous description of apparatus, method and precision to ensure uniformity)

• No objections to the adoption of the relevant (ASTM) international standard

Meeting on 6 Nov Outcome & recommendations

Meeting of task group, Barry Dumas Trevor Distin and Dave Wright

1. Adopt international standard (ASTM, EN) Where options exist

– Select appropriate one(s)– Issue a recommendation– Incorporate in national standards (or SABS)

2. Sabita to develop (user friendly) bench methods (training manuals) to ensure compliance with the standard adopted

Recommendations/cont…

3. Introduce through SABS only if it admits the adoption of options (e.g. Marshall hammer type described in 1.2 of ASTM D 6926 or extraction method(s) A – E in ASTM D2172)

4. Retrain laboratory technicians/testers on standard adopted and manuals (bench methods) by AsAc

5. Submit the above to RPF6. If acceptable, task team to proceed to investigate

suitable standard and implementation thereof on lab floor for submission to next RPF

7. Approach MTC through established channels