TESTING THE SHEAR STRENGTH OF MASONRY BUILT WITH LIME MORTAR

Tvrđa u Osijeku pretrpjela je snažan potres 1964. Međutim, sve zgrade pretrpjele su potres s neznatnim oštećenjem ili su čak neoštećene. Naravno, u vrijeme njegove izgradnje nije bilo nikakvih protupotresnih propisa. Potres uzrokuje horizontalno opterećenje na zidove zgrade, koji se odupiru posmičnom čvrstoćom. Cilj ovog rada je utvrditi stvarna mehanička svojstva objekata povijesne baštine u Osijeku. Ispitivani zidni elemenati (puni glineni elementi) izvorno su iz Tvrđe. Tlačna čvrstoća zidnih elemenata i vapneni mort ispitani su prema važećim propisima. Uzorci ziđa izrađeni su pomoću propisanog vapnenog morta kako bi se smatrali izvornima. Posmična čvrstoća ziđa dobivena je za devet ispitnih uzoraka podvrgnutih cikličkom opterećenju. Rezultati ispitivanja bilježeni su računalom. Podaci su obrađeni pomodu programa Microsoft Excel.Tvrđa in Osijek was suffered a strong earthquake in 1964. However, all the buildings survived the earthquake only slightly damaged or even undamaged. Of course, at the time of its construction there were no aseismic regulations. The earthquake causes the horizontal load to the building walls, which are resisted by the shear strength. The aim of this paper is to determine the actual mechanical properties of historical heritage buildings in Osijek. Tested masonry unites (solid clay bricks) were originall from Tvrđa. The compressive strength of masonry units and lime mortar were estimated according to current regulations. The wall specimens were made using prescribed lime mortar so to be considered as filled. Masonry shear strength characteristics were obtained for nine test specimens subjected to cyclic loading. Test results were recording by computer. Data were processed using Microsoft Excel