The effect of heavy persistent actions into the behaviour of ancient masonry

The recent collapses of massive masonry structures like towers and domes have shown that the traditional stress-strain analysis is not prepared to take into account some particular aspects that are relevant for the safety assessment of ancient buildings. In this paper, the important influence of persistent loads into the damage of historic masonry is put forward and a further step into the appraisal of creep behaviour of ancient masonry is presented. By means of an experimental and numerical investigation (carried out on the material collected from the ruins of the Civic Tower of Pavia collapsed in 1989), some significant parameters describing the deviatoric and volumetric visco-elastic behaviour of the material are detected. The aim of the research is to gain experimental knowledge as a basis for mathematical modelling of long-term behaviour of masonry structures.