On September 10th 2013, I gave a lecture about my PhD research at my alma mater, the Vrije Universiteit Brussel in Brussels, Belgium.
Even though I graduated from Brussels in 2008, I have kept in touch every now and then with my former adviser and one of my former professors. When they invited me to give a lecture to their research group about my doctoral dissertation, I was more than delighted.
The abstract of the lecture was the following:
The capacity of existing reinforced concrete slab bridges in the Netherlands is subject to discussion for two reasons: 1) the increase in traffic loads and volumes and 2) the fact that the majority of the bridges was built before 1976, and these structures are reaching the end of their service life. Upon assessment according to the governing codes, a large number of slab bridges are found to be shear-critical. The shear capacity from the codes, however, is the result of experiments on beam in shear. Slabs subjected to concentrated loads (such as wheel loads of a truck) are expected to have a larger bearing capacity as a result of the transverse distribution capacity.
In this research, the capacity of slabs subjected to concentrated loads close to supports is studied. A literature review, resulting in a database of 215 experiments from the literature, is used to study the mechanisms that occur in one-way shear (beam shear) and two-way shear (punching shear). For this research, 156 experiments on 38 scale models (scale 1:2) of slab bridges are executed. The experimental results are analyzed in a parameter study.
Two methods are proposed to determine the shear capacity of slabs subjected to concentrated loads close to supports: 1) the Modified Bond Model, a new theory; and 2) an extension of the Eurocode provisions based on a probabilistic analysis according to the safety philosophy of the Eurocodes.
Finally, the connection to the assessment practice is made by means of recommendations, by improving the Quick Scan tool of the Ministry of Infrastructure and the Environment, and then applying this method to existing slab bridges.
You can find the slides of this lecture here: