Diagonal Tensile Strength of AAC Blocks Masonry with Thin Joints Superficially Strengthened by Reinforced Using GFRP Net Plastering

Abstract

In recent years, the autoclaved aerated concrete has become as one of the most popular material used in erecting of small housings as well as multi-apartment residential buildings. Recommended construction technology involves the use of the ACC blocks arranged on thin bed joints, with the head joints left unfilled. Practice has shown that this type of construction is characterised by low crack resistance, which was also confirmed during experimental investigation [1]. One of the solutions to this problem, proposed by the staff of the Silesian University of Technology, was the superficial strengthening of such type of masonry walls. Strengthening materials tested so far (glass and carbon fibre mesh used in FRP system solutions) gave very promising results but a relatively high cost of the material itself constituted the main drawback. This prompted a further search for new and relatively inexpensive materials that would allow improving the use of the existing structures made of AAC blocks. The goal of the laboratory test results presented in this paper was to determine the influence of wall surface strengthening made of not expensive GRFP mesh (dedicated as reinforcement of thin external plastering in thermal insulation systems) on the behaviour and mechanical properties of masonry wallettes made of AAC blocks with thin joints. Three series of masonry specimens were tested: not strengthened wallettes (as reference members), walls with superficial strengthening only on one side and walls with both sides strengthened. A total of 18 specimens subjected to diagonally compressive loading were tested (6 in each series). The results turned out to be highly promising. Increasing of shear capacity of both types of superficially strengthened masonry in comparison with reference members was observed. The tests also allowed determining a positive effect of external reinforcement on the type of cracking and failure mode of such walls.