A number of ungrouted and grouted masonry walls were built at the laboratory of Strength of Materials and Structures of Aristotle University using an innovative clay unit vertically perforated. This vertically perforated clay unit was designed and produced with the proper holes in order to host the required horizontal and vertical reinforcing steel bars. At the same time the remaining holes are filled with expanded polystyrene parts capable to provide sufficient thermal insulation and drastically reduce the energy consumption. The specimens constructed with the thin mortar method using a high strength mortar and employing vertical reinforcing bars of different diameters. The measured behavior is depicted here in terms of horizontal applied load versus the horizontal displacement at mid height. Furthermore, numerical models were developed in order to simulate the observed behaviour of the tested specimens by modeling separately the masonry panels as homogenized material and linear beam elements representing the employed longitudinal (vertical) reinforcement. The numerically simulated behavior resembles the measured load-deformation response of the tested specimens and the observed actual damage at the end of the tests.

A new innovative clay brick unit is used for the construction of partially grouted masonry walls. This new unit aims to provide both the required mechanical properties and thermal insulating properties. The behavior of masonry specimens constructed with this unit and thin mortar method under in plane loads is discussed here. The basic mechanical properties of the examined construction system are measured by a series of material tests, prism tests under combined shear and compression and wallets under compression tests. The laboratory measurements are compared with the defined by EC6 values. Following, diagonal compression tests were conducted at the Laboratory of Strength of Materials and Structures (Aristotle University of Thessaloniki) to ungrouted and grouted masonry wallets with different reinforcing details employing horizontal reinforcing steel bars placed at the prefabricated holes of the clay unit. The effect of the reinforcing steel bars in the bearing capacity and in the post peak behavior is investigated. Apart from the experimental investigation, numerical models simulating these tests were developed utilizing all the geometrical properties of the specimens and the mechanical properties of the materials used. The numerically simulated behavior resembles the measured load-deformation response of the tested specimens and the observed actual damage at the end of the tests.

Unreinforced masonry made of stone and low strength mortar has been used for centuries in forming the structural system of old type buildings. Wooden roofs were also used as part of such structural systems. The influence of the connections of such wooden roofs with the vertical masonry walls is the objective of this study. A number of old stone-masonry buildings used as leather factories in the island of Samos-Greece are employed in this investigation. The wooden roofs of these buildings collapsed either partly or totally during the recent earthquake of October 2020. Initially, the dynamic behaviour typical forms of such buildings with wooden roofs are studied. A variation of the connections of such a wooden roof with the vertical stone masonry walls is studied in a parametric way. Next, the earthquake response of the same structural formations are also studied using again the variation of these connections as the main parameter. Towards this end earthquake design spectra are used as well as the acceleration recordings of this earthquake ground motion by an instrument located in the Samos island. Numerical simulation results are presented and discussed. Through the comparison of the obtained numerical predictions with the observed behaviour the validity of the numerical approach is discussed.