This thesis aims to study the structural consequences of the damages produced by vehicle impact in a pres-stressed concrete bridge girder and the repair procedure in a real case-study damaged after the bridge was opened to service. From the analysis of the situation of the beam and its damage state, a study of the repair actions carried out on this beam has been analyzed in order to determine the efficiency of the repair and if other alternatives are possible or more efficient. A state of the art and current practice review for repairing similar damages is carried out in this thesis. This literature review is focused on the repair methods and techniques studied in the United States of America, where this thesis was performed. Furthermore, all repair methods are classified depending on the type of girder damage (minor, moderate and severe). This damage classification aims to avoid inefficient and improper repair actions. The most complex techniques are usually used with severe damage. After all techniques are studied and classified a repair strategy is proposed. Based on the information, concepts and techniques analyzed in the literature review, a repair procedure for a pres-stressed concrete bridge girder is proposed. All necessary steps to have a proper repair are carried out. Then, once repair strategy is proposed, a real case is studied. Following the repair strategy proposed, all steps needed to repair a pre-stressed concrete bridge girder damaged by vehicle impact are carried out. Doing this way, the suitability of the strategy proposed. A deeper understanding of the method used in this case and the process followed in its implementation is detailed. After the procedure is studied, an analysis of data from load tests performed on the beam before and after repair were made is done. With the data obtained from load tests a study of the correlation of results are done in order to obtain conclusions after repair. Finally, a simulation of the case-study is carried out in order to identify the effects of the damage in the bridge deck, structural response and the efficiency of the repair. This simulation is done using SAP 2000 structural analysis software.