Permeabilidad del hormigón: Influencia de la dosificación y métodos de ensayo

Permeability of concrete: Influence of the mix design and test method

A study on the different tecniques to test the permeability has been carried out in the Laboratorio Central de Estructuras y Materiales, in Madrid (Spain), during three years. This research programme has included several test methods to apply to specimens in laboratory, and also to obtain in situ measurements. One of them has been the water penetration method. Some operational problems can appear when the test is carried out according to ISO/DIS 7.031:1983. Some modifications were necessary to solve them, in order to develop the Spanish Standard UNE 83.309, which deals with this method. Besides, the research work has included a test progremme to asses the influence of some parameters of the dossage in the permeability of concrete. The water/cement ratio, tha maximum size of aggregate and the curing duration were taken into account. Five test methods were used in the experimental work: water penetration method, initial surface absorption test (ISAT), the Figg methods to evalulate the air and water permeability of concrete and the Hansen, Ottosen and Petersen's method for permeability of concrete to gases under low presures. About two hundred specimens with ten different dosages were tested. The first experimental results obtained with the two first methods mentioned avobe, are presented in this work.