Engineering Report:

The Embedded Hybrid All-Directions Interlocking Masonry System

Document No.: EHMS-TR-2026-001
Date: June 10, 2026
Subject: Technical Evaluation of a Patented Dry-Stack Reinforced Masonry System
Innovators: Muayad Alsamaraee & Daniel Boot
Origin: Canadian Innovation Center (Samaraee & Daniel, 2021)

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1. Executive Summary

The Embedded Hybrid All-Directions Interlocking Masonry System (EHMS) represents a novel construction methodology that integrates dry-stack interlocking masonry with embedded steel reinforcement and post-tensioning. Unlike traditional masonry, which relies on wet mortar for bonding, EHMS uses precision-manufactured compressed concrete blocks with raised ridges, grooves, or tapered projections on their bearing surfaces. When stacked, these geometric features force mechanical alignment, creating a stable assembly held by friction, gravity, and interlocking geometry. The addition of vertical and horizontal reinforcement cores transforms the system into a hybrid structure capable of resisting tensile, shear, and seismic forces. This report evaluates the engineering features, structural behavior, code-compliance potential, and seismic validation requirements of EHMS.

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2. System Overview

EHMS is a dry-stack interlocking masonry system where blocks are laid without mortar. The blocks feature precision-engineered interlocking geometry on their top, bottom, and end faces. Embedded reinforcement, consisting of rebar or post-tensioning cables, is inserted through pre-formed vertical and horizontal cavities, creating composite action similar to reinforced concrete but without wet-poured formwork.

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The core innovation combines four elements. First, mortarless assembly eliminates curing time and skilled labor requirements. Second, all-directions three-dimensional interlocking provides six-degree-of-freedom constraint between adjacent blocks. Third, embedded hybrid reinforcement supplies tensile capacity that unreinforced masonry lacks. Fourth, post-tensioning capability enables self-centering seismic behavior.

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3. Engineering Features

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3.1 Mortarless Dry-Stack Assembly with Precision Interlocking

The system eliminates mortar as a structural adhesive. Each block is manufactured with raised ridges, grooves, or dovetailed projections on its bearing surfaces, including top, bottom, and ends. These features provide automatic alignment and mechanical keying during stacking. The resulting assembly relies on friction, gravity, and geometric constraint rather than chemical bonding for initial stability. This removes curing time as a critical path factor and ensures uniform load transfer without the variability inherent in field-mixed mortar.

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3.2 Embedded Hybrid Reinforcement System

Unlike conventional dry-stack masonry, EHMS integrates steel reinforcement embedded within pre-formed block cavities. Vertical cores accept reinforcing bars or post-tensioning cables, while horizontal channels may accommodate lateral ties or grouted bond beams. This hybrid configuration provides tensile strength, which is the fundamental property that unreinforced masonry lacks. The steel handles bending moments, uplift, and diagonal tension, while the masonry handles compression. The result is composite action similar to reinforced concrete but achieved without wet-poured formwork.

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3.3 Three-Dimensional All-Directions Mechanical Locking

The term "All-Directions" indicates six-degree-of-freedom constraint between adjacent blocks. Interlocking features on the top, bottom, left, right, front, and rear faces restrict translation and rotation in all axes. This three-dimensional geometry resists vertical compression, horizontal in-plane shear (racking), and horizontal out-of-plane bending (bulging or tilting). Under lateral loads, the interlocking distributes forces across the entire wall panel rather than concentrating stress at vulnerable mortar joints. This represents a fundamental departure from traditional masonry, which relies solely on bed-joint shear strength.

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3.4 Post-Tensioning or Prestressing Capability

The system can incorporate post-tensioned reinforcement as a critical engineering feature for seismic performance. After blocks are stacked dry and vertical tendons, consisting of threaded rods or cables, are inserted, the tendons are tensioned using hydraulic jacks and anchored at the top and bottom. This applies a controlled compressive preload to the entire wall assembly. The preload increases shear friction capacity, eliminates tensile cracking under service loads, and provides self-centering behavior. Consequently, after an earthquake, the compressed assembly returns to its original position rather than retaining permanent drift.

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3.5 Ductile, Energy-Dissipating Seismic Response

Engineered interlocking dry-stack systems exhibit controlled rocking and sliding at block interfaces during seismic excitation. These micro-movements dissipate hysteretic energy using the same principle employed in base isolators and dampers, without sudden brittle failure. Unlike mortar joints, which crack catastrophically under tension, interlocking joints allow limited relative motion while maintaining stability. The embedded reinforcement then provides a collapse prevention mechanism, holding the assembly together even after significant displacement. This combination yields a ductility factor comparable to special reinforced concrete moment frames.

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3.6 Compression-Dominated Load Path with Tensile Continuity

The structural behavior follows a compression-strut-and-tie analogy augmented by continuous tension elements. Vertical loads transfer through direct block-to-block contact over large bearing areas. Lateral and uplift loads transfer through the interlocking geometry into the post-tensioning steel. Because the steel runs continuously from foundation to roof, any tensile force must be carried by the reinforcement, not the masonry. This creates a redundant, fail-safe load path that is explicitly engineerable using conventional reinforced masonry design codes, such as TMS 402 or Eurocode 6, with appropriate adjustments for dry-stack behavior.

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3.7 Precision Manufacturing and Dimensional Tolerances

Engineering performance depends entirely on tight manufacturing tolerances, typically plus or minus 0.5 millimeters or better for interlocking features. Blocks are produced using high-frequency vibration or hydraulic compression rather than wet-cast concrete, achieving dense, low-porosity units with compressive strengths exceeding 20 to 30 megapascals. This precision ensures that every interlocking contact surface bears uniformly, preventing point-loading or stress concentrations. This distinguishes the system from field-cast or poorly compressed masonry units, which would fail unpredictably under dry-stack conditions.

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3.8 Scalable Modular Geometry for Arbitrary Plan Forms

The system is modular and dimensionally coordinated, meaning all blocks derive from a base geometric module, for example, 200 millimeters by 200 millimeters by 400 millimeters. Larger structures use more blocks rather than different block types, though specialty corner, end, and tapered units accommodate geometry changes. Because stability derives from interlocking and post-tensioning rather than mortar, the system can theoretically form non-rectilinear, stepped, or battered walls, including pyramidal profiles, without loss of structural integrity. Each block remains in pure compression or transfers tension to the reinforcement.

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3.9 Embedded Utility Conduits as Integrated Features

Rather than requiring drilling or cutting after construction, the blocks include pre-formed vertical and horizontal chase-ways for electrical, plumbing, and communication lines. These chase-ways often coincide with or supplement the reinforcement cores. From an engineering perspective, this means the structural reinforcement and service distribution share the same volumetric envelope, maximizing net usable space and eliminating secondary wall penetration operations. However, designers must ensure that conduit placement does not reduce the effective cross-section of reinforcement or block bearing area below code-minimum requirements.

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3.10 Construction Engineering: Unskilled Labor with Quality Control

From a construction engineering perspective, the system decouples block manufacturing quality, which is off-site and controlled, from assembly skill, which is on-site and minimal. The interlocking geometry acts as a jig or fixture, forcing correct alignment regardless of worker experience. This reduces on-site variability, which is the primary source of masonry failures. The engineering implication is that structural reliability depends primarily on factory production tolerances rather than field workmanship. This enables predictable structural performance in disaster relief or developing-economy contexts where skilled supervision is unavailable.

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3.11 No Formwork, No Curing Time, Reduced Construction Schedule

The system requires no formwork, unlike cast-in-place concrete, and no curing delays, unlike mortar or grout. Once blocks are stacked and tendons are tensioned, the wall is immediately load-bearing. This compressed construction schedule is an engineering feature because it reduces time-dependent risks, such as collapse during curing, weather damage, or construction sequence delays. For multi-story buildings, floors can be placed as soon as the walls below are post-tensioned, eliminating typical waiting periods associated with masonry or concrete construction.

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3.12 Code-Compliant Design Potential

While dry-stack interlocking masonry is not yet covered by all building codes, the addition of embedded reinforcement and post-tensioning allows designers to use existing reinforced masonry provisions, including ACI 530/TMS 402 or Eurocode 6, with appropriate reduction factors for mortarless construction. The system's hybrid nature means that failure modes—block crushing, steel yielding, bond failure, and anchorage pull-out—are already understood and quantifiable using standard engineering mechanics. This provides a pathway to code compliance and professional engineering certification.

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4. Seismic Validation Methodology and Requirements

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4.1 The Gold Standard: Shake Table Experimentation

Shake table experimentation is widely recognized as the best method for studying the seismic behavior of buildings and structural systems. For a novel system such as EHMS, which claims superior seismic performance including ductile energy dissipation and self-centering behavior, validation through shake table testing is not merely recommended but essential. Such testing subjects a physical model of the structure to controlled earthquake ground motions, allowing engineers to observe failure modes, measure accelerations and displacements, and verify analytical predictions under realistic dynamic loading conditions.

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4.2 Scale Limitations and Gravity Effects

A significant technical constraint associated with shake table testing must be acknowledged. The carrying capacity of typical shaking tables is limited, which imposes restrictions on the size and weight of test specimens. For high-rise building models, the scale must often be reduced to less than one-twentieth (1/20) of full size to remain within the table's load limits. At such small scales, gravity acceleration effects cannot be accurately represented and therefore must be ignored or artificially compensated for in the test setup.

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This limitation has direct implications for EHMS. The system's interlocking and post-tensioning mechanisms rely heavily on gravity-induced friction and compression. In a highly scaled model where gravitational effects are not faithfully reproduced, the measured seismic response may not accurately reflect the behavior of a full-scale structure. Specifically, the controlled rocking and sliding behavior described in Section 3.5, as well as the self-centering capability described in Section 3.4, are gravity-dependent phenomena. A test that ignores gravity acceleration may underestimate or misrepresent these critical performance features.

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4.3 Recommended Testing Protocol for EHMS

To properly validate EHMS for seismic applications, the following testing protocol is recommended.

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• First, material-level and component-level tests should be conducted on full-scale block assemblies to characterize basic frictional and interlocking behavior under combined gravity and lateral loads. These tests can be performed using conventional universal testing machines rather than shake tables.

• Second, large-scale wall panel tests, at one-half scale or larger, should be conducted on a shake table with sufficient capacity. For low-to-medium rise buildings typical of EHMS target applications, full-scale single-story or two-story specimens are feasible and should be prioritized.

• Third, for any scaled testing below one-half scale, analytical or computational compensation methods must be developed and validated to account for the missing gravity effects. Finite element models calibrated against large-scale test data can then be used to extrapolate behavior to smaller scales or taller buildings.

• Fourth, a maximum credible earthquake scenario, such as a Richter magnitude 9.8 event, should be included in the test protocol as a demonstration of the system's ultimate resilience.

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4.4 Status of EHMS Validation

Based on available information, the specific EHMS technology described in this report has not yet been publicly documented as having undergone shake table validation at any scale. While the inventor, Muayad Alsamaraee, PE, introduced the system in 2021 at the Canadian Innovation Center, peer-reviewed publications or test reports demonstrating seismic performance under controlled shake table conditions are not cited in the available literature. This represents a gap between the claimed capabilities and empirically validated performance. Future development of EHMS should prioritize shake table testing as a prerequisite for code adoption and commercial deployment in seismic zones.

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5. Comparative Analysis

• When compared to traditional masonry, EHMS eliminates the requirement for mortar and curing time while adding tensile capacity and seismic self-centering behavior. Traditional masonry relies on bed-joint shear strength alone and exhibits brittle failure under tension, whereas EHMS provides three-dimensional interlocking and continuous reinforcement.

• When compared to reinforced concrete, EHMS eliminates the need for formwork and reduces skilled labor requirements. Reinforced concrete requires wet-poured formwork, curing delays, and high levels of on-site supervision, while EHMS achieves composite action through dry-stack assembly with post-tensioning.

• The system distinguishes itself from conventional dry-stack interlocking masonry by adding embedded reinforcement and post-tensioning. Basic dry-stack systems rely solely on friction and interlocking geometry, providing no tensile capacity and limited seismic performance. EHMS, by contrast, offers tensile continuity, collapse prevention, and self-centering behavior.

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However, unlike all of these established systems, EHMS lacks a validated body of shake table test data at appropriate scales. Traditional masonry and reinforced concrete have decades of empirical seismic testing supporting their code provisions. EHMS currently relies on theoretical claims and small-scale demonstrations, which, as discussed in Section 4, may not capture gravity-dependent behavior accurately.

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6. Limitations and Considerations

Several limitations must be acknowledged. Code acceptance remains incomplete, as the system is not yet universally covered by building codes and requires engineering judgment with appropriate reduction factors. Manufacturing precision demands tolerances of plus or minus 0.5 millimeters, necessitating specialized block-making equipment that may not be available in all regions. Post-tensioning expertise requires access to hydraulic tensioning equipment and trained operators for the final locking procedure. Material constraints dictate that blocks must be manufactured from compressed concrete or equivalent high-strength materials; conventional soft mud bricks are not suitable. Height limitations currently restrict the system to low-to-medium rise buildings, as high-rise applications require additional validation through full-scale testing and peer-reviewed research.

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Additionally, a critical limitation specific to seismic validation must be highlighted. As identified in shake table testing best practices, gravity acceleration effects cannot be accurately represented in highly scaled models, such as those at one-twentieth scale or smaller. Any existing or future validation of EHMS that relies on such small-scale models must be interpreted with caution, as the interlocking friction and post-tensioning compression that provide the system's seismic resistance are gravity-dependent. Full-scale or large-scale shake table testing is required to definitively validate the claimed seismic performance, particularly for Richter magnitude events approaching 9.8.

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7. Conclusions

The Embedded Hybrid All-Directions Interlocking Masonry System (EHMS) is a technically innovative concept that bridges the gap between traditional masonry, which is simple but weak, and reinforced concrete, which is strong but requires skilled labor and formwork. By combining dry-stack interlocking geometry with embedded reinforcement and post-tensioning, EHMS theoretically achieves seismic resilience through ductile, energy-dissipating behavior and self-centering capability. It enables rapid construction via mortarless assembly, no curing, and no formwork. It reduces skill dependency by using interlocking geometry as a built-in alignment jig. It provides structural redundancy with compression-dominated load paths and continuous tensile elements. Finally, it offers code-compliant potential through existing reinforced masonry frameworks.

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8. References

• Alsamaraee, M. & Daniel, D. (2021). Embedded Hybrid All-Directions Interlocking Masonry System. Canadian Innovation Center.

• TMS 402/ACI 530/ASCE 5 – Building Code Requirements for Masonry Structures.

• Eurocode 6 – Design of Masonry Structures.

• Kyoto University Studies on Wave-Shaped Interlocking Blocks: Seismic Performance Evaluation.

• Shaking table experiment is the best method to study the seismic behavior of buildings. 

• *Note: The referenced video specifically notes that for high-rise building models, scale must be less than 1/20 due to shaking table capacity limitations, and that gravity acceleration must therefore be ignored in such scaled tests.*

• Prepared by: Muayad S. Dawood Al-Samaraee

• Reviewed by: SAMANSIC Coalition - Innovation Hub   www.samansic.com

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End of Report