The density of Marshall specimens has a direct effect on stability and flow therefore the correct moulding and compaction of laboratory specimens is essential if economical design mixes are to be produced. Efficient mixing, temperature and compaction control are closely related. Poor coating of the aggregate due to low temperatures during the mixing process will have a major effect on subsequent test results.
The use of automatic compaction will result in consistent and repeatable laboratory specimens. Testing houses and design consultants who use the Marshall method of mix design will benefit from automatic compaction apparatus, which releases staff for other work during the compaction process.
The accurate measurement of stability and flow of specimens tested in a load frame is important if consistent and representative results are to be achieved. The load frames and ancillary items listed have been designed to enable technicians to test specimens quickly and easily with confident recording of results.
Ductility test is conducted to determine the amount bitumen will stretch at temperature.