Monitoring of long-term pavement performance sites in the Western Cape Province of South Africa

Abstract

In 2005, the Department of Transport and Public Works of the Western Cape province in South Africa entered into a contract with the Council for Scientific and Industrial Research (CSIR) in South Africa to start a Long-Term Pavement Performance (LTPP) programme. Two LTPP sites were initially established and monitored. The South Africa National Road Agency Ltd (SANRAL) is developing a new mechanistic-empirical pavement design method pavement design method referred to as South African Road Design System (SARDS). The SARDS will heavily rely on LTPP data to calibrate asphalt cracking and rutting performance models. In 2011, an expanded programme was approved by the Western Cape government with the primary aim of collecting more LTPP data that could assist in the calibration of rutting and cracking models incorporated in the SARDS. Monitoring of the LTPP sites is based on biannual assessments in May during the end of the dry season and in November at the end of the wet season. This paper presents and discusses the findings of the Western Cape province’s LTPP programme since its inception, showing a congregation of field and laboratory data to support the development of the new pavement design method. The methodologies used such as field sampling procedures, field and laboratory testing are presented in detailed. Field and laboratory data are compared for four LTPP sites. Recommendations to improve and sustain the Western Cape’s LTPP programme are presented.