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From page 127... ... 127 APPENDIX A Questionnaire SURVEY QUESTIONNAIRE NCHRP PROJECT 20-5 TOPIC 43-03 PRACTICES FOR UNBOUND AGGREGATE PAVEMENT LAYERS NCHRP TOPIC 43-03 SURVEY QUESTIONNAIRE February 2011 The Transportation Research Board (TRB) is preparing a Synthesis on "Practices for Unbound Aggregate Pavement Layers." This is being done for NCHRP, under the sponsorship of the American Association of State Highway and Transportation Officials (AASHTO) Read the entire page →
From page 128... ... 128 General: Use of Unbound Aggregate Base and Subbase Layers Please provide the contact information of the persons in your agency who directly deal with the material selection and characterization, as well as design and construction of unbound aggregate base and subbase layers for pavement applications. The consultants will contact the relevant personnel separately with specific questions. Read the entire page →
From page 129... ... 129 � Open graded drainage layer � Pavement working platforms for subgrade stability applications 3. What types of pavement structures designed and constructed by your agency commonly incorporate unbound aggregate layers? Read the entire page →
From page 130... ... 130 8. What is the maximum aggregate particle size (Dmax) Read the entire page →
From page 131... ... 131 14. Does your agency have specific guidelines regarding the transportation and storage (stockpiling) Read the entire page →
From page 132... ... 132 21. What laboratory tests are conducted by your agency for strength, deformation, and modulus characterization of unbound aggregates used in base and subbase course applications? Read the entire page →
From page 133... ... 133 � Compaction characteristics; i.e., optimum moisture content and maximum dry density � Shear strength properties (e.g., friction angle, CBR, etc.) � Resilient modulus � Other (please indicate) Read the entire page →
From page 134... ... 134 � Other (please indicate below) Read the entire page →
From page 135... ... 135 37. Is it common practice for your agency to construct "test strips" to establish roller patterns and check for compaction density growth of unbound aggregate base and subbase layers? Read the entire page →
From page 136... ... 136 44. Is there common interest among engineers in your agency to implement non-nuclear density measurement methods for construction quality control of unbound aggregate base/subbase layers? Read the entire page →
From page 137... ... 137 50. If you answered "Yes" to question No. Read the entire page →
From page 138... ... 138 56. If your answer to the previous question was "Yes," what tests are used by your agency for evaluating the quality of these recycled aggregates? Read the entire page →
From page 139... ... 139 62. What other tests are used by your agency to characterize recycled granular materials (RCA, RAP, and/or others from question No. Read the entire page →
From page 140... ... 140 � Seasonal fluctuations cause significant changes in subgrade soil properties � Subgrades stay frozen for extended periods (one month or longer) � More than 10 freeze-thaw cycles per year are experienced at the subgrade level � Spring thaw weakening and timing of spring load restrictions � Subgrade soils are primarily frost-susceptible (i.e., silty soils) Read the entire page →
From page 141... ... 141 75. How is the effectiveness of an open-graded aggregate drainage layer measured by your agency? Read the entire page →

From page 127...

... 127 APPENDIX A Questionnaire SURVEY QUESTIONNAIRE NCHRP PROJECT 20-5 TOPIC 43-03 PRACTICES FOR UNBOUND AGGREGATE PAVEMENT LAYERS NCHRP TOPIC 43-03 SURVEY QUESTIONNAIRE February 2011 The Transportation Research Board (TRB) is preparing a Synthesis on "Practices for Unbound Aggregate Pavement Layers." This is being done for NCHRP, under the sponsorship of the American Association of State Highway and Transportation Officials (AASHTO)