ASTM_D_7228_-_06a_2015.pdf

Designation:D722806a(Reapproved 2015)Standard Test Method forPrediction of Asphalt-Bound Pavement Layer Temperatures1This standard is issued under the fixed designation D7228;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers a means of predicting tempera-tures within the asphalt-bound layer(s)of a flexible pavementsection.1.2 Deflection testing commonly involves the measurementof pavement surface temperatures.This standard is based ontemperature relationships developed as part of the FederalHighway Administration(FHWA)Long Term Pavement Per-formance(LTPP)Seasonal Monitoring Program.2.Referenced Documents2.1 ASTM Standards:2D4694 Test Method for Deflections with a Falling-Weight-Type Impulse Load DeviceD4695 Guide for General Pavement Deflection Measure-mentsD4602 Guide for Nondestructive Testing of Pavements Us-ing Cyclic-Loading Dynamic Deflection EquipmentD5858 Guide for Calculating In Situ Equivalent ElasticModuli of Pavement Materials Using Layered ElasticTheory2.2 AASHTO Standards:3T256-00 Standard Method of Test for Pavement DeflectionMeasurementsT317-02 Standard Method of Test for Prediction of Asphalt-Bound Pavement Layer Temperatures2.3 Federal Highway Administration:4FHWA-RD-98-085,Temperature Predictions and Adjust-ment Factors for Asphalt Pavements,June 2000LTPP Guide to Asphalt Temperature Prediction and Correc-tion,Online Temperature Prediction and CorrectionGuideTOC,November 20023.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 BELLS an acronym based on the initials of the fourdevelopers of the method:Baltzer,Ertman-Larsen,Lukanen,and Stubstad.3.1.2 depththe distance below the surface of the top layerof asphalt.3.1.3 1-day air temperaturethe average of the minimumand maximum air temperatures at the location of testing duringthe previous complete 24-hour day.4.Summary of Test Method4.1 Input Data Elements:4.1.1 IR TemperatureThe exposed surface temperature ofan asphalt pavement is measured,preferably with an infrared(IR)temperature sensing device that is properly calibrated.4.1.2 Time of DayThe time of day the temperature mea-surement takes place is recorded.4.1.3 1-Day TemperatureThe average 1-day air tempera-ture of the previous complete 24-hour day is determined andrecorded.4.1.4 Pavement DepthThe depth at which an estimate ofthe asphalt layer temperature is required is specified.4.2 The input data elements are entered into a regressionformula that predicts the temperature within the asphalt pave-ment at depth.5.Significance and Use5.1 Analysis of deflection data from asphalt pavementsalmost always requires that the raw deflections or the analysisresults from the load-deflection data be adjusted for the effectsof pavement surface course temperature.Measuring the tem-perature at-depth normally requires that a hole be drilled intothe pavement,partially filled with fluid,and the temperaturemeasured with a hand-held device.Alternatively,thermistors orother temperature instrumentation may be permanently in-stalled at various locations.5.2 Current deflection testing equipment is often equippedwith surface temperature sensing devices,for example an1This test method is under the jurisdiction of ASTM Committee E17 on Vehicle-Pavement Systems and is the direct responsibility of Subcommittee E17.41 onPavement Testing and Evaluation.Current edition approved Sept.1,2015.Published December 2015.Originallyapproved in 2006.Last previous edition approved in 2011 as D7228 06A(2011).DOI:10.1520/D7228-06AR15.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from American Association of State Highway and TransportationOfficials(AASHTO),444 N.Capitol St.,NW,Suite 249,Washington,DC 20001.4Available from Federal Highway Administration(FHWA)400 Seventh Street,SW Washington,DC 20590.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 infrared thermometer that measures the surface temperature atevery test location.To adequately adjust the deflection ordeflection results for the effects of temperature,the temperatureat some depth must be known.5.3 This test method provides a means of estimating thetemperature at-depth from the pavement surface temperature,the time of day,the previous days high and low airtemperatures,and the desired depth where the temperature is tobe estimated.Utilization of this method results in a significantsavings in time over the conventional practice of manuallydrilling holes into the pavement,and it results in a significantincrease in the volume of temp