PERFORMANCE OF CONTINUOUSLY REINFORCED CONCRETE PAVEMENT IN TEXAS

A SUMMARY IS PRESENTED OF THE PERFORMANCE OF CONTINUOUSLY REINFORCED CONCRETE PAVEMENT IN TEXAS. THE PERFORMANCE OF PAVEMENT TEST SECTIONS WITH VARYING SUBBASE, SUBGRADE, AND SLAB THICKNESS CHARACTERISTICS IS EVALUATED IN TERMS OF STEEL STRAIN, DEFLECTION, CRACK PATTERN, PUMPING, AND TRAFFIC. DATA COLLECTION AND ANALYSIS TECHNIQUES WERE ESSENTIALLY THE SAME AS THOSE USED AT THE AASHO ROAD TEST WITH APPROPRIATE MODIFICATIONS FOR THE CONTINUOUSLY REINFORCED CONCRETE PAVEMENT. EMPIRICAL EQUATIONS DEVELOPED BY USING REGRESSION TECHNIQUES ARE MODIFIED FOR USE AS DESIGN TOOLS. RESULTS INDICATE THAT EACH OF THE PARAMETERS MENTIONED AFFECTS THE PERFORMANCE OF CONTINUOUSLY REINFORCED CONCRETE PAVEMENT IN SOME WAY. PAVEMENT TYPE, PAVEMENT THICKNESS, SUBBASE TYPE, AND SUBGRADE WERE ALL FOUND TO AFFECT DEFLECTION. PAVEMENTS WITH 0.5 PERCENT LONGITUDINAL STEEL PERFORM SATISFACTORILY AS TRUE CONTINUOUS PAVEMENTS, I.E., GOOD LOAD TRANSFER IS OBTAINED. THE CRACK PATTERN DEVELOPMENT IS RELATED TO PAVEMENT AGE, SUBBASE FRICTION, CONCRETE FLEXURAL STRENGTH, AND CURING TEMPERATURE. CRACK DISTRIBUTION IN A GIVEN PAVEMENT LENGTH INDICATES PERFORMANCE. A NORMAL DISTRIBUTION REFLECTS SATISFACTORY PERFORMANCE WHILE A SKEWED DISTRIBUTION REFLECTS UNSATISFACTORY PERFORMANCE. BASED ON PERCENTAGE EVALUATION, TWICE AS MANY JOINTED PAVEMENTS AS CONTINUOUS PAVEMENTS WERE FOUND PUMPING. IF NOT PROTECTED LIME-STABILIZED SUBBASES MAY PUMP. ASPHALTIC CONCRETES WITH HIGH ASPHALT CONTENT OR GOOD SURFACE TREATMENTS WILL PROTECT STABILIZED SUBBASES. SIGNS OF PUMPING ARE NOT ALWAYS PROOF THAT THE SUBBASE IS BEING ERODED. THE PRESENT SERVICEABILITY INDEXES OF CRC PAVEMENTS IN TEXAS FOLLOW THE TREND OF THE AASHO EQUATIONS BUT WITH A SOMEWHAT LOWER INITIAL PSI. CRC PAVEMENTS ARE PERFORMING WITH A SIGNIFICANTLY HIGHER PSI THAN ARE JOINTED CONCRETE PAVEMENTS WITH THE SAME NUMBER OF EQUIVALENT 18-KIP AXLE APPLICATIONS. /AUTHOR/