Durability of Bridge Deck Concrete: Fid-Bau Portal

Durability of Bridge Deck Concrete

T. D. Larson / J. J. Malloy

This report covers the first years study of durability of bridge deck concrete in Pennsylvania. The specific accomplishments of this investigation were: development of basic equipment for microscopic analysis of air voids and the composition of hardened concrete; completion of field surveys on nine bridge decks showing signs of distress, and a detailed observation of the construction of one bridge deck. For laboratory study, 47 cores were taken from the nine decks. Air determinations on these were compared with the reported field air contents. Petrographic examination was also made on these cores. On one bridge, field observations were made of the placing and curing techniques, and the water and air contents of the concretes. Conclusions of the report are: there is not perfect correlation between air content and field performance of bridge deck concrete; air content appears to be the best indicator of performance of the concrete; petrographic examinations gave indications of possible causes of failure; not enough bridges have been studied to determine relationship between deterioration and factors causing the deterioration; exposure to moisture and de-icer solutions resulting from poor drainage, accelerates deterioration; observation of new construction permits identification of factors which may aid in interpreting bridge deck failures (Author)