1. AAPA 2010 Study Tour – Perpetual Pavement Concepts Observations and Recommendations Perpetual Pavement Concepts

2. AAPA 2010 Study Tour – Perpetual Pavement Concepts 1.Fatigue Endurance Limit is an accepted concept 2.If pavement structure thick enough and FEL not exceeded then a long life flexible (LLFP) becomes a reality (termed Perpetual Pavements in marketing terms) 3.Thickness design moving from WMAP temperature to dynamic modulus at a range of temperatures to match seasonal effects www.aapa.asn.au Observations - PPC

3. AAPA 2010 Study Tour – Perpetual Pavement Concepts 4.USA Mechanistic Empirical Pavement Design Guide (MEPDG) updated to include FEL concept. Auburn University NCAT PerRoad & PerRoad Express pavement design programs provide PP design approach. Not yet part of design practice in USA. www.aapa.asn.au Observations - PPC

4. AAPA 2010 Study Tour – Perpetual Pavement Concepts 5.Marshall & Superpave mix design methods used. Still debating number of SPG cycles. Current specified cycles produce dry and low durability mixes, binder contents are being increased by reducing the number of cycles. www.aapa.asn.au Observations - PPC

5. AAPA 2010 Study Tour – Perpetual Pavement Concepts 1.AU flexible pavement design practice should investigate the opportunities for inclusion of Fatigue Endurance Limit into local practice 2.Maintain contact with USA colleague to facilitate 1. through industry, SRA, academia, consultants, ARRB personnel and Austroads Pavement Structures Reference Group. www.aapa.asn.au Recommendations - PPC

6. AAPA 2010 Study Tour – Perpetual Pavement Concepts 3.Existing lab tools in AU should be used to compare local to USA materials proven on their major highways & accelerated test facilities. 4.Develop “library” of the performance of AU pavement materials for input into local predictive models. www.aapa.asn.au Recommendations - PPC

7. AAPA 2010 Study Tour – Perpetual Pavement Concepts 5.AAPA should in its Technology Development Program the conversion of PP/LLFP design packages to SI units through partnerships with SRA / ARRB / consultants with the modification of AU design methods and tools such as CIRCLY www.aapa.asn.au Recommendations - PPC