Evaluation and Analysis of LTPP Pavement Layer Thickness Data

FIGURE 1

Figure 1 in page 14 illustrates the essential data fields and relationships between different tables (TST_AC01_LAYER, TST_PC06, SPS*_LAYER, INV_LAYER, RHB_LAYER, TST_L05B, and TST_L05A) for LTPP layer thickness data with Table TST_L05B establishing the final pavement layer structure (all layers, descriptions, material types, and representative thicknesses) for each test section using the data in those tables. The function and the essential data fields in each of those layer thickness data tables are listed as follows.

• TST_AC01_LAYER: contains AC core examination and thickness information as well as field layer and actual layer number. Key data fields include AC layers, description, measured thickness, and thickness statistics.
  
  
• TST_PC06: contains Portland cement concrete (PCC) core examination and thickness. Key data fields include PCC layers, average core thickness, and thickness statistics.
  
  
• SPS*_LAYER: summarize layer descriptions and thicknesses for newly constructed SPS layers. Key data fields include all SPS layers, description, material type, design thickness, and thickness statistics.
  
  
• INV_LAYER: contains layer descriptions and thickness data collected from highway agencies. Key data fields include all layers with construction number (CN) equal to 1, description, material type, design thickness, and thickness statistics.
  
  
• RHB_LAYER: contains layer descriptions and thickness data collected from highway agencies or rehabilitated layers. Key data fields include all layers with construction number (CN) greater than 1, description, material type, design thickness, and thickness statistics.
  
  
• TST_L05B: establishes the final pavement layer structure for each test section using the measured data in TST_L05A. Key data fields include all layers, description, material type, and representative thickness.
  
  
• TST_L05A: contains measured layer material type and thickness data at the beginning, within, and at the end of a section, based on the core measurements and field test pit information. Key data fields include all layers at different locations, description, material type, and representative thickness.
  
  

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