Performance of concrete wharves constructed between 1901 and 1928 at the Port of Montréal

Abstract

An evaluation of concrete properties of five wharves in the Port of Montréal, constructed between 1901 and 1928, was undertaken to investigate the underlying causes of deterioration. The evaluated wharves consisted of either reinforced concrete caissons or massive concrete elements. The wharves were used in the past either as cargo loading docks or for the storage of various materials, some of which were detrimental to concrete. The evaluation program included visual examination of distressed concrete located above water level and the determination of compressive strength, modulus of elasticity, rapid chloride ion permeability (RCP), water soluble chloride ion penetration profiles, as well as a detailed microstructural examination. This article discusses the various results pertaining to the quality of the concrete and Gunite repairs found in old marine structures such as these, where various modes of degradation were present including ice abrasion, cracking and spalling, alkali–silica reaction (ASR), sulfate attack, and frost damage. These various modes of deterioration affected the quality of concrete in all examined wharves as well as that of previous repair work, demonstrating the need for new repairs. However, despite exhibiting signs of severe damage, the concrete wharves had reasonable strength and elastic modulus values enabling rehabilitation to increase service life.