Axial compression behavior of concrete masonry wallettes strengthened with cement mortar overlays

Abstract

This paper presents the results of a series of axial compression tests on concrete block wallettes coated with cement mortar overlays. Different types of mortars and combinations with steel welded meshes and fibers were tested. The experimental results were discussed based on different theoretical approaches: analytical and Finite Element Method models. The main conclusions are: a) the application of mortar overlays increases the wall strength, but not in a uniform manner; b) the strengthening efficiency of wallettes loaded in axial compression is not proportional to the overlay mortar strength because it can be affected by the failure mechanisms of the wall; c) steel mesh reinforced overlays in combination with high strength mortar show better efficiency, because the steel mesh mitigates the damage effects in the block wall and in the overlays themselves; d) simplified theoretical methods of analysis as described in this paper can give satisfactory predictions of masonry wall behavior up to a certain level.

Experimental and Numerical Study on Unreinforced Brick Masonry Walls Retrofitted with Sprayed Mortar under Uniaxial Compression

“…At the peak of the load, the whole separated along the crack direction, but not the interface. A similar mode of failure was observed in the masonry study [25].…”

“…Page's research [23] concluded that the typical cracking of brick walls under double-sided compression is along the vertical direction. Thamboo's study [24] on concrete blocks and Olivera's research [25] on masonry indicate that vertical cracking arises from the masonry mortar, having a greater deformation capacity in bricks. There were three typical failure modes observed from the lateral side, which are shown in Figure 9a-c.…”

Mesh reinforcement in masonry mortar coatings: a systematic literature review

“…The behavior of masonry walls depends on the relationship between its component's properties and the efforts to which they are subjected. Reinforced coatings can be used to improve the performance of these elements in rehabilitation and retrofitting or to provide higher strengths under special load conditions, such as seismic activity [11][12][13]. The mesh reinforcement is usually applied in discrete parts of the buildings and may be used as emergency repair or as a permanent strengthening method [30].…”

“…And as retrofit for historic buildings, when the use of epoxy resins is not allowed or suitable, as in stone masonry or reversible applications [3,30,47,49]. The revised documents also covered masonry rehabilitation, the increase of load capacity on structural bearing walls [11,46], retrofit due to seismic activity [3,7,10,12,13,22,30,45,47,49,50], coating influence in compressive strength [6], and reinforcement of arches and masonry vaults [51]. A recent study also covered a detailed characterization of AFG meshes for reinforcement use [51].…”

“…Masonry performance can be improved even more if reinforcing meshes are embedded in the coating layer, a technique known for its low cost, ease of execution, and high compatibility with multiple materials [8][9][10]. This procedure provides greater mechanical strength for masonries under multiple load conditions and many studies suggest it is suitable for repair, retrofitting, and reinforcement applications, as well as seismic strengthening of non-structural infill walls [7,[11][12][13].…”