Standard Axle Loads in the Design of Motorway Pavements

Abstract

The paper considers issues of standard axle load, which is among the main design parameters when designing motorway pavements. Changing standard axle loads over time due to changes in the traffic flow composition is shown. Standard axial loads recommended for the design by the currently valid regulatory documents are given. Also, axle loads are given for trucks most widespread on domestic highways. Attention is drawn to the axle loads of modern vehicles, significantly exceeding the standard values. Also, the paper provides research data showing that more than 75 % of freight vehicles are overloaded, which also increases axle loads. These two factors – axle loads exceeding the standard values and overloaded vehicles lead to additional loads on the motorway pavement, for which it has not been designed. This, in turn, leads to the premature destruction of road pavements, the loss of their service quality, and additional costs for repairs. The paper justifies the need to increase the standard axle load when designing the motorway pavements since the use of the currently adopted value of 115 kN in the pavement design leads to insufficient strength of the pavement designed and its inability to withstand the existing loads. It is proposed to use an axial load of 150 kN as a design parameter when designing the motorway pavements.