PAVEMENT EVALUATION II

THE STUDY IS AN EXTENSION OF THE BITUMINOUS CONCRETE PAVEMENT INVENTORY STUDY REPORTED IN MARCH 1964. OBSERVATIONS OF 293 SELECTED FLEXIBLE PAVEMENT PROJECTS DISTRIBUTED THROUGHOUT THE STATE WERE MADE AND ANALYZED. THE PRINCIPAL PURPOSE OF THE STUDY IS TO MODERNIZE AND UPDATE THE PREVIOUS STUDY SO THAT THE PREVIOUSLY DEVELOPED PAVEMENT DESIGN NOMOGRAPH COULD BE REVISED. EACH PROJECTS PRESENT SERVICEABILITY WAS OBTAINED BY A SYSTEMATIC QUALITATIVE RATING SYSTEM WHICH IS CORRELATED WITH RESULTS OF CHLOE PROFILOMETER MEASUREMENTS ON A LIMITED NUMBER OF PROJECTS. TOTAL EQUIVALENT 18-KIP AXLE LOADS AND THE STRUCTURAL NUMBER OF THE TOP 18 INCHES OF THE PAVEMENT STRUCTURE OF EACH PROJECT WERE COMPUTED. RELATIONSHIPS BETWEEN LOAD, SERVICEABILITY AND STRUCTURAL NUMBER ARE DEVELOPED. THE FOLLOWING CONCLUSIONS ARE REPORTED' /1/ THE QUALITATIVE RATING SYSTEM IS NOT AS ACCURATE AS CHLOE PROFILOMETER MEASUREMENTS FOR DETERMINING PAVEMENT SERVICEABILITY. A RATING OF 2.5 BY THE FORMER METHOD IS APPROXIMATELY EQUAL TO 2.0 BY THE LATTER. /2/ PAVEMENTS WITH TREATED BASE COURSES PERFORMED BETTER THAN THOSE HAVING UNTREATED GRAVEL BASES. THE PAVEMENT DESIGN NOMOGRAPH WAS REVISED AND THE CHLOE PROFILOMETER RATING SYSTEM IS RECOMMENDED FOR ADOPTION. /BPR/