Behaviour of reinforced mortarless concrete masonry panels under axial compression: An experimental and analytical study: Fid-Bau Portal

Behaviour of reinforced mortarless concrete masonry panels under axial compression: An experimental and analytical study

Zahra, Tatheer / Dorji, Jigme / Thamboo, Julian / Cameron, Nathanael / Asad, Mohammad / Kasinski, Wojtek / Nardone, Arlene

Abstract

Highlights • Compression behaviour of RMM with changing block types, steel bars and panel heights is presented through experiments and analytical investigation. • Steel bars did not yield and did not contribute significantly to the compression capacity of RMM panels. • Grout played major role in the compression capacity improvement and bonding of mortarless blocks. • Analytical equations for compression capacity prediction and stress–strain behaviour of RMM are proposed.

Abstract Mortarless masonry can facilitate faster construction of walls over conventional mortared masonry due to the absence of a mortar laying process and availability of interlocking features on the blocks. The structural performance of mortarless masonry can be improved by grouting and providing reinforcement in hollow cores of the interlocking blocks. In this study, axial compression behaviour of the reinforced mortarless masonry (RMM) panels was investigated. The influence of mortarless block types (single and double webbed), grouting and vertical reinforcement ratios were examined to comprehend the axial compression and displacement characteristics of RMM assemblies. In total, 44 RMM panels were constructed and tested under concentric axial compression. Failure patterns, load–displacement responses and compression capacities of the RMM panels were assessed and presented in this paper. The experimental results revealed that grouting significantly improved the axial capacities of RMM panels by bonding the interlocking blocks and reducing the initial settlement in the mortarless block interfaces. The single webbed blocks had higher compressive strength as compared to double webbed blocks, however in RMM panels, early cracking and spalling of face-shells of single webbed blocks resulted in lower compression capacities and stress ratios as compared to double webbed RMM assemblies. Prediction of compression capacities of the tested RMM panels using the current design provisions of Australian Masonry Standards (AS 3700) were found conservative with a safety ratios of 1.1 (for single webbed RMM panels) and 1.4 (for double webbed RMM panels). Subsequently, an analytical stress–strain model was proposed for the RMM under axial compression by calibrating the experimental data obtained through this study.