Skin friction coefficient change on cement grouts for micropiles due to sulfate attack

This paper presents a study of skin friction change of cement pastes used for micropiles as a geotechnical foundation when grout surface is affected by sulfate attack. In this research skin friction coefficient between cement paste – cement paste was measured, studying change in friction depending on the initial roughness of samples. Tests were performed after 3 and 6 months of immersion in a 15% Na2SO4 solution. Results show that sulfate attack increases skin friction coefficient for both surface finishes, concluding that this attack does not have a negative effect on friction in the experimental conditions of this work. This research work has been financially supported by the “Ministerio de Economía y Competitividad” (formerly “Ministerio de Ciencia e Innovación”) of Spain and FEDER through project BIA2011-25721, and the University of Alicante through project GRE13-25.