Cracking in autoclaved aerated concrete: Experimental investigation and XFEM modeling

Mechanical characterization of autoclaved aerated concrete masonry subjected to in-plane loading: Experimental investigation and FE modeling

“…Poisson coefficient was instead evaluated as the ratio between horizontal and vertical strains (e h /e v ), obtaining an average value almost equal to m ffi 0.30 in both the two main directions. It can be observed that the so determined elastic properties are similar, even if not identical, to those previously derived on homogeneous panels, which were respectively equal to E = 1352 MPa and m = 0.38, as reported in [35]. Table 2 also summarizes the strains values corresponding to peak stresses, which were respectively equal, on average, to e px = 1.8‰ and e py = 2.2‰.…”

“…The first ones, characterized by a 40 mm square basis and 80 mm height, provided indeed an average uniaxial compressive strength approximately equal to f AAC = 2.8 MPa, while for 40 mm side cubes a value of f AAC,cube = 3.1 MPa was found. These values were almost coincident with those provided from standard tests previously carried out on the adopted raw material (see [35] for further details), as well as with those available in the technical literature for a material with similar density and moisture content [5,6]. Anyway, it should be kept in mind that AAC compressive strength depends on the geometry and dimensions of tested blocks.…”

“…In this way, it has been possible to keep the specimen size small, while having at the same time an adequate number of head and bed joints, so emphasizing their influence on masonry global behavior and increasing possible anisotropic effects. Therefore, the behavior of structural elements realized with larger units and a more limited number of joints should lie between the two ''limit cases" of homogeneous material (previously investigated by the same Authors in [35]) and the here investigated masonry formed by small units. In any case, experimental evidences have shown that the use of scaled bricks does not seem to alter substantially the results, as will be discussed in more details in the forthcoming Sections.…”

“…A deep characterization of the raw autoclaved aerated concrete adopted for the realization of units can be found in [35]. Its main mechanical characteristics were: average density q b = 550 kg/m 3 , average compressive strength f b = 3.1 MPa (as determined on cubes with an edge length of 100 mm), average modulus of rupture f t,b = 0.6 MPa, and elastic modulus E b = 1320 MPa.…”

“…In homogeneous samples, failure was instead mainly localized near the weaker edge, related to the expansion process. Moreover, at time of test execution, masonry samples were characterized by a slightly lower moisture content with respect to homogeneous ones ( [35]). …”