The PTF comprises the main test machine and a 25m by 10m by 3m deep concrete pit in which full-scale test pavements are constructed using conventional construction plant. Instrumentation can be installed in the pavement layers to measure stress, strain and deflection. The pavement temperature can be raised by means of two banks of infra-red heaters which are controlled by thermocouples installed in the pavement.

Key features of the PTF are:

• Trafficking rates of up to 1000 applications per hour
• 24 hour operation
• Uni- or Bi- directional wheel loading
• Trafficking speeds of 1-20 kph (± 0.25 kph)
• Wheel loads of 2.3-10 tonnes (± 2%)
• Use of dual or wide based single wheel assemblies
• Pavement heating capabilities
• Canalised or laterally distributed wheel passes (centreline ± 450mm)

The PTF can be used to assess: -

• flexible, rigid and modular pavement / footway structures and materials
• unbound and stabilised foundations
• trench reinstatements
• buried installations e.g. water or gas services
• durability of road studs and other street furniture
• drainage / telecom chambers
• geosynthetic reinforcements
• effects of wheel path realignment
• weigh-in-motion systems
• influence of different tyre types, configurations, inflation pressures and wheel loads on pavement performance

Construction

Our new facilities enable our internationally recognised technical specialists to design asphalt mixes and manufacture standard and bespoke test specimens for a wide range of contemporary private and public sector requirements. We can produce a variety of small size laboratory prepared samples using our asphalt mixer and either roller, gyratory or Marshall compaction equipment. Where appropriate, we develop new materials incorporating waste and recycled materials which can be assessed against performance based specifications. Test specimens can be designed and manufactured to ensure that they represent in-situ construction and behavioural conditions.

Asphalt materials testing

Our capabilities cover a range of the current British and CEN/European standard tests. Equipment we can offer includes Wheeltracker (deformation resistance), Scuffing (abrasion through wear), RICE test (maximum density and voids), SRV (slip resistance), together with density profile (unique gamma ray core scanner), NAT (indirect tensile and creep stiffness) and permeability (material integrity and moisture susceptibility).

These facilities can be used to assess the performance characteristics of new and recycled materials incorporated in bitumen-bound applications, as well as standard materials more traditionally used in construction. Our facilities are extensively used to independently assess, support and assist in the development of new products for a range of private sector clients, from small to medium enterprises (SMEs) to major manufacturers.

Environmental condition

Our specialised facilities include equipment to measure the freeze/thaw durability of specimens and our Montford environmental chamber to monitor the effects of temperature and humidity by a comprehensive range of sensors and data loggers.

On-site testing and monitoring

We offer a range of site testing equipment ranging from SCRIM and Deflectograph, to more specialised capabilities such as FWD, profile, texture and cracking assessment, Pavement Friction Tester (high speed skid resistance), GripTester (skid resistance), and Ground Penetrating Radar. We can also offer coring (including air flush), DCP, NDG and dynamic plate tests, together with a range of other test facilities.

New applications for our capabilities

• Comparison of CEN/BS tests methods
• Assessment of bridge deck surfacing thickness
• Applications for recycled materials in thin surfacing
• Scuffing of high friction surfaces
• Ranking of trial asphalt mix varieties.

Key past projects

• Performance assessment of bridge deck surfacings
• Early life assessment of road foundation materials - using FWD, plate bearing, and DCP testing to assess material performance
• SMART Project - development of a performance based specification for cold recycled materials, involving determination of curing characteristics of various material families during the first year after construction.

For more information contact:

John Prime
Asphalt Technologist
Telephone: +44 (0)1344 770646
Email: jprime@trl.co.uk

Dave Blackman

Laboratory Manager
Telephone: +44 (0)1344 770296
Email: dblackman@trl.co.uk