Abstract:
Flexible pavements are widely used despite some doubts regarding their economics under different conditions. Lack of research, less construction technology know-how and cement high rates compared with asphalt in the past are the main reasons for not implementing concrete pavement in Sudan.
The purpose of this study is to conduct comparison in total present cost between flexible pavement and jointed plain concrete pavement to locate a feasible long term good performance pavement type.
Two roads were selected to illustrate the case study, Elmonerra – Elsaffya road is considered as national highway (Road A), and Omdurman ring road representing the state road (Road B). The principles and cost comparison were applied for the two case study roads.
The two most important parameters that govern pavement design, namely sub -grade strength and traffic loading was determined in this study from Road A and Road B material laboratory tests reports and traffic surveying data. For flexible pavement design of both roads, the sub-grade resilient modulus MR was obtained from correlation with CBR. The design traffic in term of million ESAL was obtained from AASHTO equation for 20 year design life. The rigid pavement design used modified modulus of sub-grade reaction k as measure of sub-grade strength, while design traffic was also million ESAL.
The AASHTO and PCA methods were applied for rigid pavement design in comparative manner with AASHTO and Asphalt Institute (AI) methods for flexible pavement design.
Typical standard pavement cross sections obtained by AASHTO design for flexible and jointed plain concrete pavements were adopted for life-cycle cost analysis (LCCA). The two components of LCCA, construction and maintenance costs were calculated for the entire roads using 2014 rates. The total present-worth of cost for each road pavement cost were used for comparison. It was found that the feasible long term pavement performance can be achieved by using jointed plain concrete pavement with saving of (28 %) for road A and (6 %) for road B.
