Maintenance management of a large road network with limited resources is a challenging task in developing countries like India. Road agencies expect that the condition of their road infrastructure should always above the desired level of performance even under restricted resources. This requires an integrated decision support system considering all aspects of maintenance. In this paper, a framework for optimal maintenance decisions by multi-objective approach is formulated for a road network by considering functional condition of the pavement quantified in terms of roughness and structural condition quantified in terms of rebound deflection. A multiobjective optimization model is developed using Integer Linear Programming (ILP). A novel approach to track the age of pavement is applied in the formulation of the mathematical model. The e-constraint method is adopted to generate non-dominated solutions. Budget bound optimizing model is formulated and implemented for a typical road network of four roads and optimal maintenance scheduling is arrived.

Decision Support System for the Maintenance Management of Road Network Considering Multi-Criteria

The aim of this research programme was to develop a pavement evaluation
procedure for thinly surfaced dressed granular pavements.
Although well advanced and rational pavement evaluation techniques for
bituminous pavements are now being introduced, pavement evaluation procedures
adopted for overseas roads are still largely based on empirical data and pavement
strength is related to the maximum transient deflection of the pavement under a standard
wheel load The maximum transient deflection is merely a general indicator of the
pavement performance and incapable of identifying the weaknesses, whether they are
due to the pavement layers or its foundation. [Continues.]

Structural evaluation of thinly-surfaced granular pavements

Details are given of the performance over a period of eleven years of normally-constructed road pavements in Malaysia. Current pavement-design recommendations are compared with the thickness and quality of the pavements studied. Pavement deflection characteristics are related to performance under traffic, and deflection-criterion curves are given for reads with crusher-run bases and bitumen-macadam surfacings in the Malaysian environment. It was found that typical Malaysian bitumions overlays reduced deflections less than might be expected from experience gained elsewhere. In spite of the high rainfall in the country and the permeable pavement construction employed, it was found that subgrade moisture contents are rarely more than 2 per cent wetter than the optimum moisture content in the British Standard 2.5 kg rammer compaction test are usually significantly drier than this. It is concluded that the pavement design recommendations for flexible pavements set out in Road Notes 29 and 31 can be applied with confidence in environments similar to that of Malaysia, and that the use of sub-bases in Malaysia would be advantageous. /Author/

Pavement performance and deflection studies on malaysian roads

Research efforts were directed toward analyzing the effect of relatively high service temperatures on the deflection parameters and establishing correction factors for more accurate estimation of asphalt pavement performance. For this purpose, a continuous program of Dynaflect measurements extending over 2 years was carried out on full-depth asphalt pavement test sections in Kuwait. Measured deflection basins were correlated with those predicted by applying elastic layer theory. Cores were taken for laboratory characterization of the pavement materials under simulative conditions. Both measured and predicted values indicated a reduction in the miximum Dynaflect deflection parameter between the load wheels at pavement temperatures exceeding 40 deg C. The reduction in measured deflection values increases with the decrease of both asphalt layer thickness and its stiffness. Within the temperature range for normal Dynaflect measurements, correction have developed for the evaluation of alastic modulus values of both asphalt layers and subgrade. These correction factors have been related to a standard pavement temperature for the condition of no temperature gradient within the pavement. Corrected measured values were found to be reflecting the changes in the deflection behavior of the road pavement during high service temperatures.

Temperature dependency of dynamic deflection measurements on asphalt pavements

A Framework for Maintenance Management of Pavement Networks under Performance-Based Multi-Objective Optimization

THE LONG-TERM PERFORMANCE OF FLEXIBLE PAVEMENTS CAN BE DETERMINED BY THE MAGNITUDE OF THE TRANSIENT DEFLECTIONS WHICH OCCUR UNDER TRAFFIC. A CONTINUOUS PROGRAM OF DEFLECTION MEASUREMENTS EXTENDING OVER FIFTEEN YEARS HAS BEEN CARRIED OUT THROUGH FULL-SCALE ROAD EXPERIMENTS. OVER 300 EXPERIMENTAL SECTIONS AND, IN ADDITION, 30 LENGHTS OF MAJOR ROAD WHOSE CONSTRUCTION IS OF PARTICULAR INTEREST HAVE BEEN TESTED ANNUALLY WITH THE BENKELMAN DEFLECTION BEAM UNDER A WHEEL-LOAD OF 3175 KG (7000 LB). THE MEASURED DEFLECTIONS HAVE BEEN CORRECTED FOR THE INFLUENCE OF TEMPERATURE ON THE STIFFNESS OF THE BITUMINOUS COMPONENTS, AND THESE STANDARD DEFLECTIONS AT 20 DEGREES C HAVE BEEN RELATED: (A) TO THE AGE OF THE ROAD EXPRESSED IN TERMS OF THE CUMULATIVE TOTAL OF EQUIVALENT STANDARD 8200 KG (18,000 LB) AXLE LOADS CARRIED; AND (B) TO THE CONDITION OF THE PAVEMENT IN TERMS OF RUTTING AND CRACKING. THE DEFLECTION HISTORIES THUS DERIVED ENABLE THE DEVELOPMENT OF CRITICAL CONDITIONS WITHIN THE PAVEMENT WHEN STRENGTHENING OF THE ROAD WOULD BE MOST APPROPRIATE, TO BE RELATED TO DEFLECTION BEHAVIOR UNDER TRAFFIC. OVERLAYS HAVE BEEN APPLIED TO CERTAIN FULL-SCALE ROAD EXPERIMENTS AS THEY HAVE BEEN RETIRED FROM SERVICE AND DEFLECTION STUDIES HAVE BEEN CONTINUED. THE BEHAVIOR OF OVERLAYS LAID TO STRENGTHEN NORMAL ROADS IN BEING SIMILARLY STUDIED. DEFLECTION HISTORIES OF OVERLAID PAVEMENTS HAVE BEEN USED TO PREPARE RECOMMENDATIONS FOR OVERLAY THICKNESSES TO ACHIEVE ANY REQUIRED EXTENSION OF PAVEMENT LIFE. THE IMPLEMENTATION OF RECOMMENDATIONS FOR PAVEMENT STRENGTHENING IS CONSIDERED. /AUTHOR/

N W Lister

Papers

Deflection criteria for flexible pavements and the design of overlays