Comparison Research of Bed Joints Construction and Bed Joints Reinforcement on Shear Parameters of AAC Masonry Walls

Abstract

The work presents the results of tests on the shear parameters of walls made of AAC (autoclaved aerated concrete, f b = 4.0 N/mm 2) on the system mortar for thin M5 and M10 joints (f m = 6.1 N/mm 2 and f m = 11.9 N/mm 2) and on polyurethane glue and also walls without mortar (dry masonry). The wall compression strength (on mortar M5 class) (per EN 1052-1:2000) amounted to f c,mv = 2.97 N/mm 2 (f k = 2.48 N/mm 2), elastic modulus was E cm = 2,040 N/mm 2. Various structure of bed joints and head joints were applied and the following were used as reinforcement: steel trusses of EFZ 140/Z 140 type (Z1 type) and meshes made of plastics (Z2 type). Based on the tests carried out with regard to unreinforced elements, it was shown that the filling in of head joints with mortar had an advantageous effect on the values of cracking and destruction stresses. While, with the use of reinforcement, advantageous increase of stress was obtained only when the mortar was laid twice on both bed surfaces of masonry units. The application of reinforcement in the bed joints when the mortar was laid only on one bed joints surface of the masonry units reduced the values of cracking and destruction stresses in relation to the values obtained in the unreinforced walls.