Testing Joints between Walls Made of AAC Masonry Units

Abstract

Joints between walls are very important for structural analysis of each masonry building at the global and local level. This issue has often been neglected in the case of traditional joints and relatively squat walls. At present, the issue of wall joints is becoming particularly important due to the continuous drive for simplifying structures, introducing new technologies and materials. Eurocode 6 and other standards (American, Canadian, Chinese, and Japanese) recommend inspecting joints between walls, but no detailed procedures have been specified. This paper presents our own tests on joints between walls made of autoclaved aerated concrete (AAC) masonry units. Tests included reference models composed of two wall panels joined perpendicularly with a standard masonry bond (six models), with classic steel and modified connectors (twelve models). The shape and size of test models and the structure of a test stand were determined on the basis of the analysis of the current knowledge, pilot studies and numerical FEM (Finite Element Method) - based analyses. The analyses referred to the morphology and failure mechanism of models. Load-displacement relationships for different types of joints were compared and obtained results were related to results for reference models. The mechanisms of cracking and failure was found to vary, and clear differences in the behaviour and load capacity of each type of joint were observed. The individual working phases of joints were determined and defined, and an empirical approach was proposed for the determination of forces and displacement of wall joints.

Finite Element Study on the Shear Capacity of Traditional Joints between Walls Made of AAC Masonry Units

“…The FE study shown in this paper was performed on the basis of past experimental studies presented in [ 13 ]. The main aim of the past experimental study was to investigate the shear capacity of traditional, unreinforced joints between walls made of AAC masonry units.…”

“…In this paper, only major observations and conclusions were presented. Further details of the experimental set-up and test results can be found in [ 13 ].…”

“… Experimental observations: ( a ) Visible diagonal/vertical cracks in wall C; ( b ) Failure of the joint between the tested walls; ( c ) Results of digital image correlation measurements [ 13 ]. …”

“…The current research is a part of the ongoing research project on the connections of walls made of AAC connected using the most popular fittings available on the market, as well as various types of meshes, mats and other elements that would connect walls with each other in a simple and effective way. Results of the past studies can be found in [ 12 , 13 , 14 ]. So far, the obtained knowledge and results are promising and encourage further work in the field of describing the work of the joint and the use of new methods of constructing joints, using other connectors, using more steel elements in a given weld and optimising the shape of steel flat bars.…”

“…Materials 2020, 13, 4035 2 of 19 The density of AAC ranges from 300 to 1000 kg/m 3 , and the compressive strength is from 1.5 to 10 MPa. AAC has been used since the mid-1950s (in Europe, >40% of the construction market) as a material for making masonry structures, such as walls and prefabricated ceiling and lintel elements [4].…”