Curing Practices for Concrete Pavements (2023)

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65   Survey Questionnaire A P P E N D I X A CURING PRACTICES FOR CONCRETE PAVEMENTS NCHRP Project 20-05, Synthesis Topic 53-07 Dear AASHTO Committee on Materials and Pavements Member, NCHRP is preparing a synthesis on curing practices for concrete pavements. This is being done under the sponsorship of AASHTO in cooperation with FHWA. The objective of the synthesis is to document state DOT practice for curing concrete pavements including procedures, materials, application rates, timing, OC/QA procedures, and specific measures adopted when paving under adverse weather conditions. This survey of state DOTs is a primary means of gathering information for the synthesis. We would greatly appreciate a response from your agency. The survey is being sent to the voting DOT members of the AASHTO Committee on Materials and Pavements. If you are not the appropriate person at your organization to complete this questionnaire, please forward it to the correct person with our appreciation. Note that DOT survey responses will be shown in the published synthesis report. However, the identity of survey respondents will remain anonymous. The questions are organized to seek information on curing practices of state highway agencies. Most proposed questions include either selection of one or multiple responses from a list of possible responses, and in some questions, space is provided in the form of a box for the respondent to include other responses as appropriate. A few questions will require yes/no answers. A follow- up question will only appear if the respondent answers to the original question in a particular way. A “( )” indicates one response to be made, while “[ ]” indicates multiple selections may be made. All “Other” or “Comment” fields will have a text box to receive comments. Please complete and submit this survey by February 28, 2022. We estimate that it should take no more than 30 minutes to complete the survey. If you have any questions or problems related to this questionnaire, please contact the principal investigator Jamshid Armaghani. Thank you very much for your time and expertise.

66 Curing Practices for Concrete Pavements START OF THE SURVEY A. General Information Q1) Please enter Name: _____________________________ Title: _____________________________ Email: _____________________________ Phone: _____________________________ State DOT: _____________________________ B. General Pavement and Curing Information Please note “concrete pavements” in this survey refers to full depth construction, lane widening as well as overlays of existing concrete or asphalt pavements. Q2) How many lane miles of concrete pavements does your agency maintain? ( ) 0 ( ) 1 to 99 ( ) 100 – 999 ( ) 1,000 – 4,999 ( ) 5,000 – 9,999 ( ) 10,000 – 14,999 ( ) 15,000 – 19,999 ( ) 20,000+ If you answered (0), please go to the end of the questionnaire and submit your survey response. Thank you! Q3) How many lane miles of concrete pavements has your agency constructed in the past 15 years? ( ) 0 ( ) 0 to 99 ( ) 100 – 999 Other (Please specify in the box below) Q4) How many lane miles of concrete pavements does your agency plan to construct in the next 5 years? ( ) 0 ( ) 0 to 99 Other (Please specify in the box below) Questionnaire Tips • If you are unable to complete any question and/or need to temporarily leave the survey, you can return to the questionnaire at any time by re-entering through the survey link as long as you access the questionnaire through the same computer. Re-entering the survey will return you to the last completed question. • You may navigate the survey pages by selecting the “prev” (previous) or “next” button at the bottom of each page.

Survey Questionnaire 67 Q6) Q7) Q8) C. Curing Compounds – Questions 9 to 21 Q9) Type of curing compound specified or allowed by your agency. Wax based. Water based. Resin based. Other (Please list in the box below). Q10) Please list in the adjacent box the brand or manufacturer for each curing compound checked above. Wax based. Water based. Resin based. Other Note: Responses to this question are not included in the report to comply with NCHRP policy. Q11) What pre-qualification and/or standard qualification measures does your agency undertake for approval of a curing product? Please check all that apply. [ ] Certification from AASHTO, National Transportation Product Evaluation Program (NTPEP) [ ] Approved by state DOT product evaluation office Q5) ( ) Yes, specification ( ) Yes, special provision ( ) No If yes, please provide a link for your agency specification and/or special provisions for curing. What curing materials does your agency specify or allow for concrete pavement construction? Check all that apply. [ ] ASTM Type I curing compound. [ ] ASTM Type II curing compound. [ ] Polyethylene sheeting. See below. [ ] Wet Burlap or Burlene. See below. [ ] Cotton mats. See below. [ ] Water spray, fogging or misting. See below. [ ] Evaporation retarders. See below. Of those curing materials checked above, please list in the box below the combinations that include either a Type I or II curing compound your agency would allow to be used and the criteria, if any, associated with the use of that combination. Does your agency have specification/special provisions for curing of concrete pavements? Please check all that apply.

68 Curing Practices for Concrete Pavements [ ] Testing conducted at DOT chemistry/materials laboratory to verify performance. [ ] Certification of approval from other State DOTs. [ ] Other method (Please list in the box below). Q12) Does your agency have a process for identifying unacceptable curing products or processes? ( ) Yes ( ) No If “yes”, please specify in the box below the agency process/specification or test method used Q13) What is (are) the specified rate(s) of application allowed by your agency? Please choose from the following ranges: ( ) One gallon per 50 ft2 -100 ft2 surface. ( ) One gallon per 101 ft2 - 150 ft2 surface. ( ) One gallon per 151 ft2 - 200 ft2 surface. ( ) Other _____________ Q14) Based on your response, what criteria does your agency use to determine the rate of application? ( ) Manufacturer’s recommendation ( ) Laboratory testing results; if checked, then list the testing standard used ( ) Other (Explain)________________________________ Q15) What method of application does your agency specify or allow? Please check all that apply. [ ] Self-propelled mechanical sprayer for slip-formed pavement. [ ] Hand-held sprayer for slip-formed pavement. [ ] Self-propelled mechanical sprayer for side-formed pavement. [ ] Hand-held sprayer for side-formed pavement. Q16) How is the criteria for the time of curing established? Please check all that apply. [ ] By agency specification. [ ] By the Engineer’s judgement. [ ] By the Contractor’s judgement. [ ] None Q17) What factors/data is (are) used by the criteria? Please check all that apply [ ] Data from embedded sensors (e.g., maturity meter). If so, list the type of sensors [ ] Data from hand held sensing device(s). If so, list the device(s) [ ] Weather condition data. If so, list the type of weather data [ ] Visual observation data (disappearance of sheen from the concrete surface). [ ] Other test of method data? Please specify in the box below ______________________________ [ ] None

Survey Questionnaire 69 Q18) What qualification measures/testing does your agency undertake to verify the proper application rate, quality of spraying and applicators’ proficiency? Please check those that apply. [ ] Use of a calibration template on pavement surface [ ] Curing bridge calibration (e.g., speed of travel) [ ] Other (i.e., curing of a pavement test strip). Please list in the box below items such as degree of uniformity, proper dosage rate, etc. Q19) What QC measures are allowed to ensure uniformity of curing application? Please check all that apply. [ ] Visual inspection for any spots or bands of gray. [ ] Inventory of the amount of curing material used. [ ] Scheduled cleaning/inspection of spray nozzles. [ ] Application rate measurements. [ ] Other (Please list in the box below) ______________________ [ ] None Q20) What QC/QA requirements are specified for curing? [ ] Volatile organic compound (VOC) validation. [ ] Verification of full coverage on flat and vertical surfaces. [ ] Visual/photographic inspection for whiteness. [ ] Other (Please specify in the box below) ______________________ [ ] None. Q21) What software does your agency use for curing QA/QC? Please check all that apply [ ] HIPERPAV. [ ] Customized Excel spreadsheet. [ ] Other software (Please explain in the box below) _______________________ [ ] None. Q22) What sensors are used by your agency to monitor curing quality? Please check all that apply [ ] Wind meters. [ ] Strain gauge sensors. [ ] TDR's (Time Domain Reflectometer). [ ] Relative humidity sensors. [ ] Temperature gauges or meters. [ ] Other (Please explain in the box below) _____________________________ [ ] None.

70 Curing Practices for Concrete Pavements Q23) How does your agency address early aged uncontrolled cracking. [ ] Investigate causes. (if checked, please see Q24) [ ] Leave slab in place. (if checked, please see Q24) [ ] Remove and replace slab, (if checked, please see Q24) [ ] Other (Please explain in the box below) ____________________________ Q24) For any of the first three checked in Q23, please list in the adjacent box the associated criteria. [ ] Investigate causes. Is it an isolated case or continuous occurrence? [ ] Leave slab in place; With or without a penalty; repair (please list the nature of the repair, e.g., rout and seal the crack), and/or require a new QC plan [ ] Remove and replace slab: Please explain any additional measures required such as require a new QC plan. Q25) What criteria does your agency use to define acceptable weather conditions for paving cured concrete? Check and respond to all that apply. [ ] Temperature (say, greater than 40oF and less than 90oF)? [ ] Relative humidity (> 20%). [ ] Wind speed (< 40 mph) [ ] Chance of rain or snow (<60%) [ ] Use ACI 308 evaporation limit criteria [ ] Other (Please explain in the box below) ________________________ Q26) What criteria does your agency use to define adverse weather conditions for paving? Please check/respond to all that apply. [ ] Temperature (>90oF or <40oF). [ ] Relative humidity (< 20%). [ ] Wind speed (> 40mph). [ ] Chance of rain or snow (>80%) [ ] Use ACI 308 evaporation limit criteria [ ] Other (Please explain in box below) ________________________ Q27) What additional curing measures does your agency consider when paving under adverse weather conditions? Please check all that apply. For each one checked, list the associated criteria noted in Q19. [ ] Cover the pavement with protective sheeting. [ ] Set up vertical barrier to lessen impact of high wind. [ ] Increase application rate in hot, dry and high wind conditions. [ ] Halt paving operations. [ ] Use curing blankets to cover the curing compound when anticipating very cold temperatures. [ ] In hot weather switch to nighttime paving. [ ] Use evaporation retarders in very dry warm weather to prevent evaporation prior to curing. [ ] Please add additional clarifications in the box below.

Survey Questionnaire 71 Q28) Has your agency incorporated internal curing in concrete pavement construction? ( ) Yes (please see Q29) ( ) No (please see Q30) Q29) Please list in the box below projects that incorporated internal curing. Q30) Please list in box below any projects that could be a candidate for a case study on curing. Q31) Does your agency specify curing for high early strength (HES) concrete for replacement slabs or repair patches in concrete pavement rehabilitation projects requiring short lane closures? ( ) Yes ( ) No Q32) What curing method does your agency specify for HES concrete for short lane closures? Please check all answers apply. [ ] Type I curing compound [ ] Type II curing compound [ ] Curing blankets [ ] Wet burlap [ ] Please add additional clarifications in the box below. D. Follow Up Interview The synthesis will include case examples to illustrate extensive experience of some highway agencies in curing practices on concrete pavements. With your approval, we would like to conduct a phone interview with you to collect specific information on the curing practices of your agency and use your agency information as one of the case examples. Would you be interested in participating in this effort? ( ) Yes ( ) No END OF QUESTIONNAIRE THANK YOU FOR YOUR TIME AND THE VALUABLE INFORMATION