Review on Use of End-Area-Rule for Volume Calculations in Highway Pavements

Abstract

Volume estimation of highway pavements is very important in planning and design of highways, in order to calculate the amount of materials and hence for cost analysis. It is also used to investigate the workmanship and quality of construction in post analysis. End area rule is the simplest and most widely used technique in volume calculation as it can be used with the cross sections generated at a suitable interval. The theory being used for road segment between two consecutive cross sections assuming there exists a linear variation of cross sectional areas within the interval. Validity of the application of end area rule depends on this assumption and accuracy also varies when the linear variation does not exist. This study was carried out to analyze the validity of the application of end area rule due to the non-linearity of variation of cross sectional areas in highway pavements. The scope of the study was limited to straight segment with rectangular cross section. Road width and height of the cross section were selected as variables and the volumes were compared using different models with coaxial centroids and skew sections. Numerical models with different angles of centroids were used in the study and the results were verified using digital models created with AutoCAD 3D software. The interval between sections was also investigated and it was determined that the perpendicular distance between sections should be used in the end area rule. Finally it was concluded that the area variation is not linear when there are more than one variable affect the cross section. The modification to end area rule was also developed in order to increase the accuracy.