ABSTRACT

ABSTRACT: The use of high performance concrete (HPC) having a W/C or W/B ratio between 0.30 and 0.40 increases the service life of concrete structures because HPC are more durable than concretes having a W/C or W/B greater than 0.50. But, in order to reach a 100-year life cycle with HPC it is absolutely necessary that these concretes be placed and cure appropriately to avoid the development of a too high autogenous shrinkage. Some HPC structures recently built have been severely cracked very rapidly because they wee built as if they were built with a normal strength concrete having a W/C or W/B ratio greater than 0.50. Ignoring the negative effect of the volumetric contruction of the hydrated cement paste when this construction occurs in the absence of an external source of water resulted in an early cracking. This early cracking is due to the tensile stresses developed in the menisci that are appearing within the cement paste due to chemical contraction.