This contribution is a study of the durability and transport properties of sprayed concrete used in an actual construction site. It considers whether concrete spraying can generate different porosities as the thickness of the sprayed layer increases. The work consisted of a study of the properties of the interior and exterior concrete layers with a particular focus on chloride penetration. A few of the methodologies and techniques used are compressive strength at 28 days, depth of penetration of water under pressure UNE EN 12390-8, boiled absorption and volume of permeable voids ASTM C642, and accelerate chloride penetration NT BUILD 443. Calculated transport property values included absorption (A) and volume of permeable voids (VPV), porosity interconnection, and chloride diffusion coefficient (De). The conclusion obtained is that there are no significant differences between the physical microstructural properties of the interior and exterior sprayed concrete layers, they present a similar porosity, and behave in the same way under a chloride attack when test tubes are completely saturated.

The authors gratefully acknowledge to the competitive project BIA2016-78740-R: “Materiales proyectados ligeros para refuerzo y la rehabilitación del patrimonio urbano” funded by the Ministry of Economy and Competitiveness, within the 2016 Call for projects “Excelencia y Retos”. General Directorate of Scientific and Technical Research. Subdirectorate General for Research Projects.