Simple tests and mechanical model for masonry materials at high temperatures

An experimental procedure for tests on specimens made of several materials is performed to detect the mechanical properties depending from temperature. About 200 cylindrical specimens of several materials (clay, lightweight concrete, aerate autoclaved concrete, mortar) are tested from 20°C to 700°C. The free thermal strain and the decay of axial strength are determined; proposals for the stress-strain curves and the secant modulus of elasticity in function of temperature are illustrated. The data base from tests are able to calculate the collapse domains (bending moment - axial force - time of exposure to nominal fire) which represent a simple model for the assessment of masonry panel sections subjected to fire action