Road-inspection services

Tender description

TII requires a service provider to revise a standard for road pavement skid resistance. The service will include: — carry out a comprehensive overview of literature available, — carry out overview of conventional methods of aggregate friction assessment and identify and propose systems to address gaps, — carry out comparison of current and proposed methodologies and applicable standards in other jurisdictions, — collect, analyse and collate samples from existing quarries and sites over 3 years, — assess correlation and relationships with current assessment techniques, — develop databases using samples from existing quarries and sites, — develop tool/framework to be incorporated in the assessment and approval of aggregates for use in surface courses, — develop proof of concept and test for network wide application including blind test matching, — develop validation and approval techniques to be incorporated in a future standard, — revise the standard. TII has, in standard DN-PAV-03023, recognised a need to better understand the in service performance of aggregates to enable refinements and improvements to its standards and product specifications. The introduction of the construction products regulations supports the demonstrable performance of construction products against standard property tests, aimed at ensuring adherence to the set of fundamental basic requirements. Further section 4.21 of TII DN-PAV-03023 states: “It is essential that the aggregate supplied to site must be the same in all respects to the sample submitted for acceptance”, section 4.18 states: “It is important to demonstrate consistency of production and robustness of testing”, and section 4.15 that: “Standards to be adopted in subsequent renewal work may then be determined in the light of the skidding resistance performance set against those initial recorded values”. The principal objectives of the standard are therefore to: — have an effective traceability of the materials used from quarry to site, — have the ability to make future changes based on reliable data of past performance, — ensure testing methodologies are sufficiently robust. To ensure that aggregates in surface course mixtures have adequate frictional and durability properties that are utilised in the pavement, it is important to be able to verify that the original source (quarry) of the aggregate has rock of required and resilient mineralogy. This project is aimed at supporting this principle and providing producers and specifiers with additional tools to predict the in-service performance of these aggregates. It is envisaged that an outcome would include a tool/framework that utilises spectra identification and pattern analysis for assistance in detecting and explaining variability in the frictional and physical properties of aggregates within a quarry over a period of time. The spectra framework for various aggregates could also be used as diagnostic tools to validate an aggregate source, and to enable specifiers to consider, with confidence a wider range of aggregate sources tailored to meet a more extensive list of site categories. The project also needs to establish the robustness of surface roughness (micro texture) measurement data and minerology to compliment or enhance the existing PSV test procedure (IS EN 1097-8) and friction after polishing test (IS EN 12697-49). The relationship between virgin aggregate and in situ trafficked aggregates is also an important requirement that needs to be determined. A high medium and low volume site will be identified for each source during the project. Each will be within 50 km of a source quarry.