Deterioration of road barrier protection ability due to variable road friction

Abstract

The paper presents an analysis of road barrier performance due to variable friction between tires and the ground under different weather conditions. Analyses are based on the TB42 and TB51 test, wherein a vehicle impacts a KTC 033 and KTC 015 steel barrier. A full-scale experiment using a Renault Midlum truck and a SETRA S215L bus was conducted according to the EN 1317 regulation in order to validate a numerical model. A series of numerical tests were conducted in order to investigate the influence of the friction coefficient (µwr = 0–1.1) on the normative test results. We proved that in TB 42 test on a very slippery road, the working width WN is equal to 1.6 m, while for a test conducted in good weather conditions (i.e. a dry and clean road) it is only 0.9 m. Thus, it can be stated that the EN 1317 norm may not provide sufficient information about road barrier safety. The behaviour of a barrier cannot be easily anticipated during impact in poor weather conditions, when surface-wheel contact is insufficient.