An investigation of the damage caused by road traffic on three reinforced concrete bridges was performed.
This study was performed with a focus on the determination of the damage induced by heavy vehicles
in relation to the damage caused by average everyday traffic. A damage model based on fatigue of
reinforcement bars was employed. The stress cycles in the reinforcement bars were determined using
measurements of the crack widths under traffic loading. Stress cycles were analyzed using the Rainflow
Method and Miner’s Rule was employed to gain a measurement for the damage. Monitoring systems were
installed on each of the three bridges and operated for several weeks continuously to collect input data
for the damage model. Computer software was developed to process the monitoring data in the sense of
the damage model. The described methodology was developed and used for the first time in the described
project.
Heavy traffic was shown to cause a disproportionate high portion of the overall damage on all three
bridges. The obtained results indicated that the damage caused by singular events, such as the passage of
a heavy vehicle, in relation to the damaging effects of every-day traffic differed significantly between the
considered bridges. For one of the bridges the greatest damage from singular traffic events was computed
for passages of special transport vehicles. The same bridge was also found to display the highest damage
by a single passage in relation to average everyday traffic. Passages of short and heavy trucks with four
and five axles were identified as the most detrimental traffic events on the other two bridges.