Significant Findings from Full-Scale Accelerated Pavement Testing (2004)

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183 APPENDIX F Accelerated Pavement Testing Systems with Artificial Cooling and/or Heating Control Units Entity/APT Acronym Capacity to Cool Capacity to Heat Capacity to Control Chamber Temperature Range of temperature Capacity to Control Pavement Temperature Range of Temperature ARRB ALF No Yes n/a n/a Yes Ambient up to 60°C CAL/APT HVS Richmond Yes Yes Yes Not monitored since heating and cooling is controlled by thermocouples in the pavement. In general, must run hotter than pavement at hot temperatures, colder than pavement at cold temperatures. Yes Surface Temperatures: To date facility has operated at 10°C (very short time); 20°C most of the time; 55°C for several months at a time. CAL/APT HVS Palmdale Yes Yes Yes The HVS maintained 20°C (with a small variation), despite large variations in external air temperatures. Yes Mostly operated at 20°C, or without temperature control on concrete. Temperature controlled slabs are influenced by adjacent slabs not temperature controlled. Accordingly, it is being used less often on concrete. DRTM Denmark Yes Yes Yes, building enclosure with air conditioning units. −10°C to +40°C Yes −4°C at subgrade level after 2 months. Temperature then raised to 25°C in stages for testing after thawing. ERDC– CRREL HVS Mk IV Yes Yes, building enclosure only. No infra-red heaters attached to the HVS. Yes, building enclosure only. −3.9°C to 24°C (±2°C) Yes, surface panels used to freeze/heat. Brine at −37°C is used to freeze pavement to given depth. Frosting 25 mm per 24 h is feasible. When frost penetration depth is reached, panels are removed and APT is done during thawing. −37°C to +49°C ERDC–GSL HVS–A (Bigfoot) Yes Yes Yes, the compartment under the HVS 4°C to 38°C Yes, limited, depending upon environmental conditions. Asphalt temperature of 25°C has been maintained year round. FAA NAPTF No No Yes, building enclosure only. −1°C to 35°C Not controlled, but measured. 2°C to 27°C

184 Entity/APT Acronym Capacity to Cool Capacity to Heat Capacity to Control Chamber Temperature Range of Temperature Capacity to Control Permanent Temperature Range of Temperature FDOT HVS Mk IV No Yes Yes, using air conditioning with a detachable insulation chamber. Ambient to 70°C Yes Ambient to 70°C (six heating zones independently controlled using resistance-type radiant heaters). FHWA PTF ALF 1 No Yes n/a n/a Yes Tests have been conducted between ambient (10°C) and 76°C at mid-depth of the pavement. Upper limit is higher. FHWA PTF ALF 2 No Yes n/a n/a Yes 10°C–76°C KSU–CISL K–ATL Yes Yes No −20°C to +60°C Not to a very exact value −10°C to +45°C LCPC France No Yes n/a n/a Yes Approximately 10°C above ambient temperature. ORITE OHIO APLF Yes Yes Yes −12°C to 54°C Yes, through air temperature −12°C to 54°C SA– Gautrans/ CSIR HVS Mk III Yes Yes Yes −26°C air temperature in chamber −5°C pavement temperature Yes −5 to 40°C. 50°C maximum pavement temperature is achievable, possibly even higher. SA– Gautrans/ CSIR HVS Mk VI+ Yes Yes Yes −26°C air temperature in chamber −5°C pavement temperature Yes −5 to 40°C. 50°C maximum pavement temperature is achievable, possibly even higher. Entity/APT Acronym Capacity to Cool Capacity to Heat Capacity to Control Chamber Temperature Range of Temperature Capacity to Control Permanent Temperature Range of Temperature TRL PTF No Yes No Up to about 25°C above ambient Pavement temperature can be controlled by feedback from sensors in pavement Ambient to 45°C TUDelft– DWW/ LINTRACK No Yes Surrounded by a mobile chamber used to insulate the machine. Heat accomplished by radiant heaters. n/a Yes 30–35°C above ambient temperature (depending on wind); until now maximum applied temperature was 40°C at pavement surface. University of Illinois/ IUT2 ATLaS Yes Yes No, but environmental cover used to protect the machine. n/a No n/a VTT, Finnra and VTI HVS– Nordic Yes Yes Yes, using aircondition- ing with a detachable insulation chamber −5ºC to +30ºC Not controlled but measured