Utilisation of topologically-interlocking osteomorphic blocks for multi-purpose civil construction

[Truncated abstract] Interlocking block systems have gained popularity in various forms of construction, ranging from masonry to segmental retaining walls, to segmental block paving. The main attraction of the interlocking systems compared to the traditional brick and mortar construction methods are the significant labour cost and time savings, even though the manufacturing cost of interlocking blocks is higher. Currently, each commercial block system is developed for a specific construction purpose (i.e. masonry block systems cannot be used block paving, or segmental retaining wall systems cannot be used to construct load-bearing structures). A new form of interlocking block based on the concept of topological interlocking, shows potential to be used for multiple construction purposes. Topological interlocking is based on special shapes of blocks without keys or connectors as opposite to commercial interlocking block systems. Thus in the presence of the peripheral constraint each block is kept in place by kinematic constraints imposed by the neighbouring blocks. A particularly important and versatile example of topological interlocking is the system based on the osteomorphic blocks. Osteomorphic blocks have specially curved working surfaces such that they can be interlocked to form both planar structures and corners. The osteomorphic blocks also have the unique ability to assemble into various types of column elements that integrate seamlessly with planar wall elements. In this thesis, the focus is on 2 types of osteomorphic blocks, with its curved interfaces formed by either the sinusoidal/cosine (SC) or circular arc (CA) functions. Quantifying the mechanical behaviour of osteomorphic blocks and developing the concept of utilising this system for various construction purposes forms the main objective of this research.
The applications considered include load-bearing masonry structures with vibration attenuation capabilities, segmental retaining walls, and segmental block paving. A summary of the research obtained for each application is presented below. In load-bearing masonry structures based on osteomorphic blocks the key issue is the axial compression capacity. Osteomorphic blocks for masonry construction Scaled experiments coupled with Finite-element numerical modelling showed that where the blocks are dry-stacked, its axial capacity is governed by the maximum slope of the curvilinear interfaces. Under axial compression, partial interface sliding occurs and results in protrusive deformation of the interlocking crests away from the main block body. This deformation trend subsequently causes localised formation of tensile stresses within the block body, akin to driving a wedge into a rock fissure. The tensile stress formation can potentially lead to splitting failure before the block material's compressive strength can be fully mobilised...
Thesis (Ph.D.)--University of Western Australia, 2012