Model Mobile Load Simulator

For decades pavement and material engineers have been trying to predict the in-service performance of pavement and material systems. The Model Mobile Load Simulator (MMLS), together with an experienced team of operators, can be used to make these predictions, both on-site and within the laboratory.

The MMLS is an accelerated pavement testing tool that allows the application of realistic wheel contact stresses for evaluation of pavement structures and road paving materials in terms of rutting, fatigue and susceptibility to moisture damage.

The MMLS consists of four axles, each with a 300mm diameter inflated pneumatic wheel, circulating in a vertical closed loop. The wheels are supported in bogies that are linked by an endless chain. An electric motor is used to rotate a drive drum, which draws the test wheels across the test pavement. The wheels can be laterally displaced around the central axis, making the wheel path 240 mm wide. The wander pattern can be programmed to follow a number of different distributions. Axle loads are automatically kept constant through a special suspension system at 2.7kN (or any other selected load within the specifi cation range of the device). The nominal wheel speed is 2.5m/s resulting in 7200 wheel loadings per hour. Slower speeds can be selected if desired.

Various attachments have been developed to increase the MMLS’s capabilities. These include:

• An environmental chamber to control temperature in fi eld or in the laboratory at between -5 and 60°C in wet and dry conditions.
• A precision profi lometer to measure cross sectional rut profiles to an accuracy of ±0.1mm.
• A core tray to host nine 150mm diameter samples for testing of bituminous mixtures in the laboratory under wet and dry conditions.
• A steel drum laboratory compactor to prepare laboratory pavement samples for testing.