Effect of partial saturation of soil pastes between masonry stones in the tensile strength of the masonry walls
Effect of partial saturation of soil pastes between masonry stones in the tensile strength of the masonry walls
Stone masonry walls without mortar of any kind are often analysed and modelled on the assumption that there is practically no cementing agent of any kind between stones. The whole wall therefore is considered a purely frictional assembly of high strength units, the stones, interlocked between them because of the building arrangement. Field observations of existing walls however indicate that there is always a thin film of soil between stones. This film may be the result of soil deposition following water transport from soil masses retained by the wall, the product of erosion from stone units due to micromovement between them at their contacts or weathering and on occasion actual use of soil mortar by ancient builders, as for instance evidence suggests in some prehistoric monuments. In addition, quite often this film of soil paste or slurry is found in an unsaturated condition. The paper presents the experimental work carried out to investigate the effect of the existence of this film of soil between stones of various types of rock under various values of the degree of saturation of the soil paste and the suction inside it. In all cases, fully saturated soil pastes induced lower friction between stones and practically no tensile strength under drained conditions, but very high tensile strength as the soil pastes dried especially close to their residual water content. These test results indicate that under weather conditions imposing partial saturation to existing soil pastes between masonry wall stones, masonry walls should be considered having some tensile strength. The paper concludes by attempting to introduce this tensile strength in a finite element analysis of a masonry wall.
Michael Bardanis
4th International Symposium on the Preservation of Monuments and Historic Sites
Materials, Monitoring and Geotechnical Investigation Methods
https://doi.org/10.53243/tc301-2026-76