Testing the Freeze/Thaw Cycles in Lime Mortar

2nd Historic Mortars Conference - HMC 2010 and RILEM TC 203-RHM Final Workshop, Prague, September 2010

The purpose of this study is to evaluate the behaviour of lime mortars in cold climates, namely by the effect of freeze/thaw cycles. Twelve compositions of mortars were prepared by varying the type of binder (air lime, hydraulic lime and air lime plus cement) and the grain size distribution of the sand and by including an air entraining agent. Tests, including the open porosity, mechanical strength and resistance to freeze/thaw cycles, were conducted in order to evaluate the performance of lime mortars in cold climates. The analysis of results allowed the determination of relevant conclusions about the influence of the grain size of aggregate, the use of an air entraining agent and the behaviour of mortars with different types of binder to be drawn. The open porosity depends mainly on the granulometry of sands while the mechanical strength is correlated with the binder type. These two characteristics have a great influence on the strength of mortar during freeze/thaw cycles and consequently on their performance in cold climates.