Search

Waste materials may be used as raw materials for interlocking masonry products in order to contribute to sustainable development and environmental protection. Rubberized concrete Interlocking Brick (RCIB) was developed by volumetric replacement of 56% of the ordinary Portland cement with fly ash and 20% of the sand with crumb rubber (CR) to reduce the production cost of conventional concrete bricks (CCB) and restrict the depletion of natural resources and contributing to solving the environmental problems associated with the accumulation of scrap tires in landfills. The mechanical and sustainability evaluation of masonry prism made of the developed brick is the aim of this research. Consequently, compressive strength, failure mechanism, stress–strain behaviour, and energy absorption of grouted and ungrouted prisms made of RCIB were measured experimentally under axial compression load. The thermal resistance, fuel consumption, CO2 emission, and cost analysis of RCIBs were estimated. The findings reveal that grout had a significant impact on the compressive strength of rubberized concrete interlocking masonry prisms where the compressive strength of grouted and ungrouted prisms was 10.99 MPa and 5.83 MPa, respectively. Web splitting and vertical cracks were the common failure modes observed in both prisms. Moreover, the rubberized concrete interlocking masonry prisms revealed greater energy absorption as well as a gradual and ductile failure mechanism. The RCIB exhibited higher thermal resistance than CCB (increased from 0.106 to 0.171 m2 K/W) which could contribute to a 62% reduction in annual fuel consumption and CO2 emission. Further, more than 25% of the material cost could be saved.

Mortar-less construction with interlocking bricks has many advantages, such as improved construction efficiency and relatively low requirements on labour skills. Nevertheless, the seismic performance of interlocking brick structures is not well understood yet. In this paper, laboratory tests and numerical modelling are carried out to investigate the seismic behaviour of interlocking brick walls. Laboratory shaking table tests are performed on a scaled reinforced mortar-less interlocking brick wall. The response and damage modes under in-plane seismic loading are investigated. A detailed numerical model is then generated and validated with the laboratory testing data. Unlike the conventional masonry wall that diagonal shear damage governs the failure, the interlocking brick wall exhibits rocking responses, whose damage is mainly at the two bottom corners of the wall. Full-scale interlocking brick walls are then modelled and compared with conventional concrete masonry unit (CMU) walls bonded by mortar. Comparisons are made between the seismic resistances and damage modes of the two walls. The influences of ground motion intensities, vertical components of seismic excitations and different seismic time histories on the seismic behaviour of the interlocking brick wall are examined. It is found that the interlocking brick wall has a higher seismic resistance capacity than the conventional CMU wall. Inter-brick friction is the main energy dissipation mechanism in the interlocking brick wall. Because of the rocking response, vertical component of the ground motion significantly influences the damage of interlocking brick wall. The interlocking brick wall is insensitive to velocity pulses of ground motions due to its relatively high natural frequency. [ABSTRACT FROM AUTHOR]

Fine aggregate and cement have been partially replaced by 10% and 56% crumb rubber and class F-fly ash, respectively, in order to manufacture rubberized concrete interlocking bricks (RCIBs). The newly developed product has been used for masonry construction without the need for mortar (mortarless), and the experimental testing under compression load was investigated by Al-Fakih et al. Therefore, in line with that, this study carried out finite element (FE) analysis for experimental result validation of masonry walls and prisms made of RCIBs. ANSYS software was utilized to implement the FE analysis, and a plasticity detailed micro-modeling approach was adopted. Parametric studies were carried out on masonry prisms to investigate the effect of the slenderness ratio and the elastic modulus of grout on the prism behavior. The results found that the adopted FE model has the ability to predict the structural response, such as compressive strength, stiffness, and failure mechanism, of the interlocking masonry prisms with about a 90% agreement with the experimental results. Based on the parametric studies, the compressive strength for a 6-course prism is approximately 68% less than a 3-course prism and 60% less than a 5-course prism, which means that the slenderness ratio plays a vital role in the behavior of the RCIB masonry prism under the vertical compression load. Moreover, the results showed that the difference between FE and experimental results of the walls was less than 16%, indicating a good match. The findings also reported that masonry walls and prisms experienced higher ductility measured by the post-failure loading under compression. The finite element model can be used for further investigation of masonry systems built with rubberized concrete interlocking bricks. [ABSTRACT FROM AUTHOR]

Masonry structure is one of the most commonly used building types in developing countries due to its inexpensiveness and material availability. While masonry structure is intrinsically strong in resisting gravitational force, it is relatively weak in resisting lateral forces such as an earthquake. Therefore, reinforcement for masonry structures in earthquake-prone areas is necessary. This paper introduced an interlocking brick as one of the promising reinforcement methods for masonry structure as it does not require extra material and is easy to implement. The performance of a lego-shaped interlocking brick in resisting dynamic lateral forces was investigated through 2-dimensional dynamic finite element analysis. The created lego-shaped interlocking brick wall was analyzed under the out-of-plane dynamic loading. Its performance was compared with the performance of the rectangular brick wall. The analysis results showed that the lego-shaped interlocking brick wall had better performance in resisting out-of-plane loading than the rectangular brick wall since the blocks interlock each other. [ABSTRACT FROM AUTHOR]

This study determines the suitability of using shredded waste plastic and waste ceramic powder (WCP) to produce interlocking concrete blocks (ICB). The study adopted a concrete mix ratio of 1:2 containing 20 % partial replacement of sand with ceramic waste. The compressive strength, splitting tensile strength, and water absorption of the interlocking concrete blocks were determined, after 7, 28, and 90 days of curing. The ICBs developed include mixes containing plastic fibres in proportions 0, 0.5, 1, 1.5, and 2% by weight of concrete, and a control mix with zero ceramic waste and plastic fibres. The microstructure and mineralogy of selected samples were observed using a scanning electron microscopy (SEM) and XRD (X-ray diffraction), respectively. From the result, compressive strength and splitting tensile strength of the interlocking concrete blocks increased with an increasing plastic fibre content. Also, the microscale tests revealed good compactness, and interparticle reactions in the matrix. Thus, the study recommends 2% of plastic fibre content for the production of interlocking concrete blocks.

This paper introduces a homogenisation technique for dry-stacking interlocking masonry structures to improve the modelling and computational efficiency when such interlocking brick walls are subjected to blast loading. Based on periodic construction pattern, a representative volume element (RVE) is derived, whose equivalent material properties are determined through numerical modelling under different stress states. Nonlinear material properties and strain rate effects are both considered in the numerical simulations of the RVE. The hardening and softening behaviour of the RVE are analysed using compressive and tensile damage scalars based on the theory of continuum damage mechanics. To verify the suitability and accuracy of the obtained equivalent material properties, interlocking brick walls subjected to TNT blast loading, gas explosion loading and impact loading are modelled using the homogenised material properties. The results are compared with those obtained from detailed numerical models of the interlocking brick wall and the test data for the impact loading case. It is found that the developed homogenisation approach could significantly reduce computational resource. • Homogenised interlocking brick structure modelling considering blast loading. • Equivalent properties obtained from representative volume element. • Nonlinear material properties with strain rate effect considered. • Homogenised model saves over 90% computational time compared to detailed model. [ABSTRACT FROM AUTHOR]

This paper presents an extensive numerical study on the impact behaviour of plate-like assemblies made of interlocking concrete bricks. In the proposed 3D finite element model, a damage based concrete model is employed with considerations of strain rate effect and concrete failure criteria. Boundary conditions are appropriately defined to simulate various initial loading scenarios. The impact responses of both monolithic and assembly plates are investigated, and the numerical model is validated by comparing the predicted results with experimental data. Compared to the monolithic plate, the structural flexibility, energy absorption capacity and the tolerance to local failure are improved in the assembly plates made of interlocking bricks. A comparative study is also carried out on the assembly plates made of two types of interlocking bricks including osteomorphic brick with two curved side surfaces and newly designed interlocking brick with four curved surfaces. It is found that the plate made by the newly developed interlocking brick exhibits less deflection and absorbs more energy than the existing osteomorphic brick. [ABSTRACT FROM AUTHOR]

In this paper we study a new type of interlocking brick recently proposed by the authors. The brick has a symmetrical geometry with four concavo-convex side surfaces for the interlocking purpose. Drop weight tests have been conducted to investigate the mechanical response of interlocking assembly plates by applying different levels of impact force and lateral confining load. The results show that, compared with monolithic plates, the new interlocking assembly plates have significantly improved flexural performance in terms of impact energy absorption capacity. The fracture of individual bricks during the impact always occurs along a load transmission path that is determined by the geometrical constraints of the interlocking bricks. Most importantly, the interlocking design of the plate-like assembly can effectively prevent the propagation and spread of the cracks, so that the damage to a single brick will not lead to a catastrophic failure of the entire structure. [ABSTRACT FROM AUTHOR]

• The studied interlocking brick wall exhibits a considerable deformation capacity. • The wall strength keeps increasing after the formation of major diagonal cracks. • The equivalent damping ratio decreases with the imposed displacement. • DIC analysis reveals the subtle inter-brick movements. Interlocking brick masonry has gained much attention due to its high construction efficiency and low labour skill requirement. Most designs of interlocking bricks only use interlocking keys to provide alignment for easy construction, and most previous studies of interlocking masonry structures concentrate on their static loading capacities. This study examines the behaviour of reinforced mortarless interlocking brick walls under cyclic loading. Interlocking brick wall made of a specific type of interlocking bricks with large keys that provide not only alignment in construction but also shear resistance is constructed and tested under in-plane cyclic loading. A detailed numerical model is generated and validated with the testing data, which is then used to assist the analysis of wall responses. The damage mode, hysteresis response and energy dissipation characteristics are analysed. The test results are compared with conventional masonry wall from literature to demonstrate the superior performance of interlocking masonry wall in resisting seismic loading and dissipating seismic energy. The influences of axial precompression and shear span-to-length ratio are investigated via numerical modelling. [ABSTRACT FROM AUTHOR]

Abstract: A series of laboratory tests have been conducted to investigate the fatigue behaviour of interlocking grouted stabilized mud-fly ash brick masonry. Three cases of loading at 0°, 45° and 90° to the bed joints are considered. The brick units and masonry system developed by Sinha is used in present investigation. Eighteen specimens of size 500mm×700mm×100mm and nine specimens of size 500mm×500mm×100mm are tested. For each of three levels of minimum stress, the number of cycles to failure is determined for each of various maximum stress levels considered. The fatigue study presented here is limited to approximately 8000 load cycles. For the range of tests considered, it is found that the effect of repeated compressive loading can cause reduction in the compressive strength of brick masonry as high as 25%. [Copyright &y& Elsevier]

• Optimal mix for making rubberized interlocking brick (RIB) was reported. • Experimental results for flexural strength of RIB masonry walls were presented. • RIB units were not induced any influence on the lateral load resistance. • Flexural strength was increased with an increase in pre-compression load. • Flexural load was closely predicted using theoretical analysis. Waste and industrial by-products, such as crumb rubber and fly ash, are being utilized as raw materials for making various masonry products. Rubberized concrete interlocking brick (RIB) is a newly developed product incorporated 10% crumb rubber, as a partial replacement for sand, and 56% fly ash, as a partial replacement for cement. The study experimentally emphasized understanding the behavior of masonry walls made of the developed rubberized interlocking bricks under out-of-plane load, with and without precompression load. The compressive strength of the developed loadbearing RIB was 18.4 MPa. The results of flexural strength, moment–curvature relationship, displacement responses, joint opening, and failure modes for masonry walls made of the developed RIB under lateral load parallel to the dry bed joints are discussed. An analytical analysis to predict the cracking flexural load is presented and compared with the experimental results. The results show that by increasing the pre-compression load, flexural strength, and moment capacity of the rubberized interlocking masonry walls increased linearly. The lateral displacement was 10.82, 24.99, and 29.69 mm for masonry walls subjected to a 0, 56, and 112 kN pre-compression loads, respectively. Flexural failure along the width of masonry walls with a course opening at mid-height was the dominant failure mode. It can also be concluded that the theoretical cracking flexural load closely matches the laboratory load. [ABSTRACT FROM AUTHOR]