Investigation of Cracking of Mass Concrete Members Induced by Restrained Contraction

摘要

The paper presents aspects of an investigation made upon the cracking states induced by early age restrained shrinkage of concrete, at the piers and abutments of the bridges from the new Transylvania Motorway, Romania. The National Building Research Institute [INCERC] Cluj-Napoca Branch and Technical University of Cluj-Napoca performed the investigation at the request of the general contractor Bechtel International Inc. Ltd. At approximately one month age of concrete, cracks width range between 0.05-0.5 mm (0.002-0.02 in) were observed. The paper emphasizes the analyses, interpretations and analytical predictions for the future progress of the cracking states, based on the data acquired from the technical documentation supplied by general contractor, and monitoring of the crack widths. The good match of theoretical results with the real registered data led to the conclusion that cracking states are caused mainly by restrained volume contraction within the first week. Thus, repair measures could be done in time and the normal progress of the works continued.