Chloride migration in structural lightweight aggregate concrete produced with different binders

• Chloride penetration resistance of lightweight aggregate concrete is characterized.
• Chloride migration, capillary absorption and resistivity tests were performed.
• Chloride penetration resistance can be greatly affected by the type of binder.
• The type of aggregate had a little influence on the chloride penetration resistance.
• Chloride penetration resistance should not be related to the compression strength.

This paper characterizes the chloride penetration resistance of structural lightweight aggregate concrete (SLWAC) produced with different types of aggregates and binders, for usual compressive strengths of about 20–65 MPa. Concrete is characterized by means of capillary absorption, electrical resistivity and accelerated chloride migration tests. In general, it was found that the chloride penetration resistance can be substantially affected by the type of binder. Besides the microstructural refinement effect, the mineral admixtures should also affect the ionic composition of the pore solution. The type of aggregate had a little influence on the chloride penetration resistance. Chloride penetration resistance should not be related to the compression strength of concrete. However, chloride diffusion is exponentially related to the w/c ratio, regardless the type of aggregate. The capillarity and resistivity results did not correlate well with those from the chloride migration test. It is concluded that SLWAC with less porous aggregate can be at least as resistant as normal weight concrete.