Rock Interface Shear System
The ShearTrac III system is capable of performing the consolidation and shearing phases of a rock core up to 152 mm (6 in) diameter. The same system can also perform a direct or residual shear test on a 305 x 305 x 205 mm (12 x 12 x 8 in) soil/aggregate specimen, as well as other tests such as interface shear or direct simple shear.
Testing is performed under fully automated control with convenient monitoring and instant test results. It consists of a computer-controlled unit using independent, electro-mechanical micro-stepper systems to apply highly precise vertical and horizontal loads.
With its high load capacity, broad range of testing flexibility, and overall ease of use the ShearTrac III is the preferred large shear machine on the market.
Regardless of pavement type or surface treatment, runway friction characteristics will change over time depending on type and frequency of aircraft activity, weather, environmental issues, and other factors. In addition to ordinary mechanical wear and tear from aircraft tires, contaminants can collect on runway pavement surfaces to decrease their friction properties. Contaminants such as rubber deposits, dust particles, jet fuel, oil spillage, water, snow, ice, and slush all cause friction loss on runway pavement surfaces. Rubber deposits occur in the touchdown areas on runways and can be quite extensive. Heavy rubber deposits can completely cover the pavement surface texture thereby causing loss of aircraft braking capability and directional control when runways are wet.
As to the frequency of testing, the FAA advises: "Every runway for jet aircraft should be evaluated at least once each year. Depending on the volume and type (weight) of traffic on the runways, evaluations will be needed more frequently, with the most heavily used runways needing evaluation as often as weekly, as rubber deposits build up."
Features
- State-of-the-art precision engineering
- Leader in reliability and environmental friendliness
- Built-to-last design dramatically reduces maintenance and operating expense