In any projects for asphalt overlay, sometimes the final product may not conform to the requirements of the specification (In this case to the
So pre-determined acceptance criteria in the form of payment deduction, as provided in the relevant specification (In this case MRS30) may be applied to nonconformances for the following properties:
particle size distribution and binder content in asphalt
insitu air voids, and
Deductions apply to the scheduled rate for the quantity of asphalt represented by the test sample (lot or sub-lot as appropriate).
The requirements of Clause 1.2
I have put some information below by referring to the MRTS30 & MRS30 which is related to the insitu air voids requirement and payment deduction criteria in case of non-conformance and I help this will be good read for quick understanding.
1.2 Performance requirements
The asphalt must not ravel, rut, shove, strip or bleed for the first 24 months after the Date of Practical Completion, and the surface of the asphalt must comply with the surface shape requirements specified in Table
9.6.2 Requirement for surface shape
The surface of any trafficked layer must not pond water.
The surface shape of each course within and across traffic lanes at the time of construction
Shape correction is typically completed using a dense graded asphalt corrector
All non-conformances shall be corrected before testing ride quality and before any subsequent course is placed.
9.2 Insitu air voids
9.2.1 Requirements for insitu air voids
The asphalt must have a dense appearance. Each layer of asphalt must be uniformly compacted to achieve the specified characteristic values for insitu air voids.
Asphalt layers of ≤ 30 mm thickness shall not be tested for insitu air voids.
The characteristic values of insitu air voids for the lot must comply with Table 9.2.1(a) for dense graded asphalt, and with
Joints are not usually tested unless the Administrator suspects the specified requirements have not been achieved. Where this occurs, the Administrator may order tests to confirm compliance.
For dense graded asphalt and stone mastic asphalt, insitu air voids below the minimum value may lead to rutting, flushing, bleeding and/or mix instability. Factors that influence the performance of the asphalt include traffic loading, depth of the layer from the pavement surface and the binder used in the asphalt mix.
Insitu air voids above the maximum value may lead to accelerated hardening of the binder (through oxidation), ravelling, ingress of moisture and/or stripping of the asphalt layer.
Pavement joints are typically accepted as areas with insitu air voids below the minimum value for the mat, as is represented by the lower compaction standard specified. However, under some circumstances the Administrator may consider testing of joint compaction by the Contractor where there are concerns that these reduced compaction standards may not have been achieved, for example:
• Process concerns brought about by visual or other surveillance indications, or
• Process verification at the commencement of the works, or where
Typically joint compaction would be tested across joints where both adjoining sections of asphalt have been placed under the same contract, or within 150 mm of joints where the asphalt being tested is adjacent to
3.3 Insitu air voids
Deductions in accordance with Table
proof rolling test of the underlying pavement (to confirm its strength) prior to placing asphalt. This requirement will be included in the next update of MRTS30.
Use an AC10M/AC14M mix for fiddly areas such as areas which are subject to light traffic).
These mixes will be easier to compact and achieve the insitu air voids requirements. AC10H/AC14H should only be used for areas subject to heavy traffic.