Heavy Vehicle Simulator (Mark IV & V)
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For further information please contact EquipmentSales@dynatest.com
The Heavy Vehicle Simulator (HVS) is a mobile machine used to subject roads to accelerated trafficking. It can simulate 20 years of road deterioration in as little as three months, thus helping engineers to understand the mechanisms of road failure caused by traffic and, to some extent, by environmental factors.
Accelerated Pavement Testing (APT) has gained momentum in the USA and worldwide, with a number of APT programs operated by various authorities.
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Since 1978, more than 400 test sections have been tested with the South African fleet of four HVSs (one prototype Mark II and three Mark IIIs).
This work has had a major impact on road engineering in South Africa, yielding significant cost savings.
The modernized HVS Mark IV and HVS-A Mark V is marketed by Dynatest.
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Three HVS Mark IIIs are still operational and highly productive: One in South Africa, belonging to the Gauteng Department of Transportation (Gautrans) and operated by CSIR, and two in California, operated for the California Department of Transportation (Caltrans), as part of the Partnered Pavement Research Center (PPRC) - formerly CAL/APT) project at the University of California, Berkley (UCB).
Three of the new, fully automated HVS Mark IVs are now operational,one at the Cold Regions Research & Engineering Laboratory (CRREL) of the U.S.Army Corps of Engineers,
one at VTT in Finland and VTI in Sweden (joint project),
and the third at the Florida Department of Transportation's (FDOT) new pavement testing and research center.
A new HVS Mark IV+ with dynamic loading capability is operated by CSIR in South Africa. |
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A heavy loading airfield version of the HVS (the HVS-A Mark V) is being operated by the Waterways Experiment Station (U.S.Army Corps of Engineers), which is capable of simulating aircraft wheel loads up to 440 kN (110 kips). |
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The HVS's are hydraulically operated. |
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The test beam loads either a single or a dual test wheel, which is driven backwards and forwards over a 6 m (~ 20 ft.) length of pavement (track width up to 1.5 m or 5 ft., depending on wheels used).
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The test section can be trafficked bi-directionally to maximize productivity or uni-directionally when appropriate. The HVS can apply wheel loads between 30 kN and 200 kN (7-45 kips) at speeds of up to 12 km/h (~ 8 mph). This allows the HVS to accelerate load-associated distress and simulate overloading effectively. The HVS-A Mark V tests a 12 m (~40 ft.) pavement section with loads up to 440 kN (100 kips). |
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The HVS Mark IV and HVS-A Mark V are highly mobile – it can be moved between test sites by being towed by a prime mover. On a specific test site, it can be moved between test sections under its own power. |
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Ability to Simulate Environmental Influences |
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Environmental influences, such as temperature and moisture variation in the pavement structure, can be simulated through a set of special add-on facilities including a temperature control chamber.
This capacity allows researchers to interpret HVS data relative to the performance of pavement under actual traffic and controlled temperature conditions.
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Moisture effects have also been studied through the use of simple surface watering systems as well as subgrade injection techniques. |
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