EVALUATION OF THE WEATHERING OF STONE MASONRY DUE TO FREEZE-THAW CYCLES

The present study aims to contribute a better knowledge on the behavior of stone masonry subject to freeze-thaw cycles; to evaluate the wear progress on the materials, the physical and mechanical characteristics of stone masonry were determined by means of units, couplets and masonry assemblages (wallets) of granite stone and lime mortar. The freeze-thaw cycles were simulated in the laboratory; the control during various cycles was by a campaign of characterization tests. The evaluation of the mechanical properties, through flexural and compressive tests before and after being subjected to cycles, led to the prediction of wear on the units. The shear strength on masonry assemblages were obtained by means of diagonal compression tests, in addition the form of collapse was analyzed to define the wear of the mortar joints. The mortar bond strength were obtained based on tensile tests of granite and mortar couplet specimens, determined the loss of adhesion between the bonds of the mortar joints. The principals results obtained in this investigation are the variation of the physical properties like the increment of the internal porosity structure, the reduction of mechanical strength, and the loss of adherence on the joint mortars on the masonry assemblages.