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CFRP is an alternative technique for cracking control of high-chloride reinforced concrete (RC) beams. This research, therefore, investigates the strength performance and failure mode and cracking behaviour of RC beams incorporated with sea sand bonded externally with the carbon fibre reinforced polymer (CFRP) plate. Sea sand is used as a 100% replacement of fine aggregate. Three batches of RC beams were carried out in this research, including the control beam (no sea sand neither CFRP), RC beam with normal sand bonded with CFRP plate, and RC beam with sea sand and bonded with CFRP. A four-point bending test was performed under static loading for the specimens. Finite element simulation was modelled for further comparison. The experimental findings showed that the flexural capacity of the sea sand RC beam bonded externally with CFRP plate is 5.50% greater than the flexural strength of the beam without CFRP (control beam). Besides, results demonstrated that RC beams bonded externally with CFRP were failed by plate end debonding (PED) while the control RC beam without bonding was failed at the mid-span by concrete crushing. However, the bonded RC beams were stiffer, which could lead to lower crack spacing. Finite element simulation showed very acceptable results compared to the experimental results.

The Disposal of Scrap Tires has Resulted in Major Environmental Problems Worldwide. Therefore, Utilizing Scrap Tires as Crumb Rubber is being Used in Brick Production to Improve the Properties of the Bricks as well as to Provide Feasible Waste Management of Scrap Tires. this Study Presents the Literature Research on Utilizing Crumb Rubber in Bricks Manufacturing. the Review Summarized the Manufacturing Process of Producing Crumb Rubber and then Documented the Application of Crumb Rubber in Masonry. the Results Show that the Compressive Strength of Masonry Bricks Decreases with the Increased Percentage Substitution of Crumb Rubber as a Replacement of Fine Aggregate while the Water Absorption Increased. Moreover, the Addition of Crumb Rubber in Masonry Applications Reduce the Density which Produce Lightweight Masonry Products. Generally, the Findings Confirmed that the Masonry Bricks Incorporated Crumb Rubber Exhibit Good Physical and Mechanical Properties. the Usage of Crumb Rubber in Bricks Making Helps to Solve Problems Associated with Scrap Tire Management all over the World.

The rapid growth in the construction industry has dictated the utilisation of the eco-friendly materials and recycling of wastes to produce sustainable products. In this study, rubberized concrete interlocking bricks have been developed by utilising crumb rubber (10%) and fly ash (56%) as partial replacements of sand and OPC, respectively. It is aimed to develop mean and characteristic compressive strength correlations of rubberized concrete interlocking hollow and grouted wall systems, corresponding to rubberized concrete interlocking brick and prism strengths. A systematic investigation of 20 rubberized concrete interlocking brick units, 10 hollow and grouted rubberized concrete interlocking prisms and 10 identical hollow and grouted rubberized concrete interlocking wall panels were cast, constructed and tested under compressive load. Results were statistically analysed and the design-charts for the mean and characteristic compressive strength of masonry were used. The results obtained for the strength of rubberized concrete interlocking brick, prism and wall revealed a normal distribution with 5% significant interval. Four types of regression models were proposed for statistical analysis and the best fit model was identified based on r2 (correlation coefficient). The power model for the mean and characteristic strength curves presented the best fit to the sorted data. The cracking pattern and modes of failure of the tested specimens were discussed. The relationships for characteristic strengths of rubberized concrete interlocking masonry hollow and grouted wall were derived in terms of rubberized concrete interlocking unit and prism strength and found to be fkw = 1.533fb 0.290, fkw = 2.178fb 0.337 and fkw = 1.119fp0.659, fkw = 1.023fp0.731, respectively.

High-Performance Self-Compacting Concrete (HPSCC) has experienced increasing demand over the past few years due to its enhanced mechanical properties and high bonding strength. These attributes make it preferable for use in structures, such as tall multi-story buildings, where high workability, strength and bending capacity are required. The objective of the present study is to investigate the shear and flexural behavior of HPSCC beams with no coarse aggregate and compressive strength of above 100 MPa. The influence of different types of steel fibre on the mechanical properties and failure modes of reinforced HPSCC beams were studied. In addition, the influence of the beam's span to effective depth ratio (a/d), longitudinal and transverse reinforcement ratios on the behavior of the HPSCC beams was studied. The results showed that the influence of the type of steel fibre is more significant than the influence of longitudinal reinforcement ratio. Moreover, the ultimate load and deformation capacity of HPSCC beams increased considerably for the beam specimens with steel fibre. However, it was shown that the non-fibre beams with d/4 shear link spacing had a higher ductility compared to the counterpart steel fibre beams with d/2 shear link spacing and with the same amount of longitudinal reinforcement ratio.

Researchers have used crumb rubber in the manufacturing of engineered cementitious composites (ECC) as a solution for spalling, however, it reduces the mechanical and physical properties. Therefore, this research reviews the available and related literature reviews on rubberized ECC and its constituent. The role of each constituent in a rubberized ECC mix is also reviewed. It’s concluded that utilizing rubberized ECC helps to solve environmental issues relating to improper disposal of tyres. As a result, fly ash has been the most common substance utilized in rubberized ECC by scholars all over the world over the past years because of its encouraging impacts on rheology, matrix toughness control, and interactive effect between fiber and matrix. It’s also found that the rectification of the crumb rubber drawbacks in ECC is by incorporating a modern method of adopting nano-silica, Polyvinyl alcohol (PVA) fibers, graphene oxide into the rubberized ECC mixes. Therefore, rubberized ECC can be utilized for civil engineering applications, especially with the inclusion of nano-silica and graphene oxide, as a result of its high ductility and low permeability.

The concrete-filled double skin steel tube (CFDST) is a more viable option compared to a concrete-filled steel tube (CFST) due to consisting a hollow section, while degradation is enhanced simply by using carbon fiber-reinforced polymer (CFRP). Hence, the stabilization of a concrete&rsquo, s ductile strength needs high- performance fiber-reinforced cementitious conmposite. This study investigates the behavior of high-performance fiber-reinforced cementitious composite-filled double-skin steel tube (HPCFDST) beams strengthened longitudinally with various layers, lengths, and configurtion of CFRP sheets. The findings showed that, with increased CFRP layers, the moment capacity and flexural stiffness values of the retrofitted HPCFDST beams have significantly improved. For an instant, the moment capacity of HPCFDST beams improved by approximately 28.5% and 32.6% when they were wrapped partially along 100% with two and three layers, respectively, compared to the control beam. Moreover, the moment capacity of the HPCFDST beam using two partial layers of CFRP along 75% of its sufficient length was closed to the findings of the beam with two full CFRP layers. For energy absorption, the results showed a vast disparity. Only the two layers with a 100% full length and partial wrapping showed increasing performance over the control. Furthermore, the typical failure mode of HPCFDST beams was observed to be local buckling at the top surface near the point of loading and CFRP rapture at the bottom of effect length.

Deep beams are more susceptible to shear failure, and therefore reparation is a crucial for structural reinforcements. Shear failure is structural concrete failure in nature. It generally occurs without warning, however, it is acceptable for the beam to fail in bending but not in shear. The experimental study presented the structural behavior of the deep beams of reinforced concrete (RC) that reinforces the web openings with externally connected carbon fiber reinforced polymer (CFRP) composite in the shear zone. The structural behavior includes a failure mode, and cracking pattern, load deflection responses, stress concentration and the reinforcement factor were investigated. A total of nine reinforced concrete deep beams with openings strengthened with CFRP and one control beam without an opening have been cast and tested under static four-point bending load till failure. The experimental results showed that the increase the size of the opening causes an increase in the shear strength reduction by up to 30%. Therefore, the larger the openings, the lower the capability of load carriage, in addition to an increase in the number of CFRP layers that could enhance the load carrying capacity. Consequently, utilization of the CFRP layer wrapping technique strengthened the shear behavior of the reinforced concrete deep beams from about 10% to 40%. It was concluded that the most effective number of CFRP layers for the deep beam with opening sizes of 150 mm and 200 mm were two layers and three layers, respectively.

Engineered cementitious composite (ECC) was discovered as a new substitute of conventional concrete as it provides better results in terms of tensile strain, reaching beyond 3%. From then, more studies were done to partially replace crumb rubber with sand to achieve a more sustainable and eco-friendlier composite from the original ECC. However, the elastic modulus of ECC was noticeably degraded. This could bring potential unseen dangerous consequences as the fatigue might happen at any time without any sign. The replacement of crumb rubber was then found to not only bring a more sustainable and eco-friendlier result but also increase the ductility and the durability of the composite, with lighter specific gravity compared to conventional concrete. This study investigated the effects of crumb rubber (CR) and graphene oxide (GO) toward the deformable properties of rubberized ECC, including the compressive strength, elastic modulus, Poisson&rsquo, s ratio, and drying shrinkage. Central composite design (CCD) was utilized to provide 13 reasonable trial mixtures with the ranging level of CR replacement from 0&ndash, 30% and that of GO from 0.01&ndash, 0.08%. The results show that GO increased the strength of the developed GO-RECC. It was also found that the addition of CR and GO to ECC brought a notable improvement in mechanical and deformable properties. The predicted model that was developed using response surface methodology (RSM) shows that the variables (compression strength, elastic modulus, Poisson&rsquo, s ratio, and drying shrinkage) rely on the independent (CR and GO) variables and are highly correlated.

Multi-layers of carbon fibre reinforced polymer (CFRP) were used to strengthen engineered cementitious composites (ECC) to study their effects on flexural and tensile strengths. Response Surface Methodology RSM was used to obtain the number of trial mixes. A total of 13 mix designs were suggested with two variables: polyvinyl alcohol (PVA) fibre (0.5 %, 1.25 % and 2.0 %) and number of CFRP (1, 3 and 5 layers). The result showed that the flexural strength of specimens with 0.5 % and 2.0 % PVA fibre was enhanced by more than 40 % and 55 %, respectively, when the CFRP layers were increased to 3 and 5 layers, which subsequently increased the absorption energy of the specimens by more than 20 %. Moreover, the tensile strength of the specimens with 1.25 % and 2.0 % PVA fibre improved by 31 % and 61 %, respectively, after these have been strengthened with 3 and 5 CFRP layers. To validate these results, the experimental responses were analysed and optimised using RSM. The coefficient of determination R2 yielded high values at 0.9647 and 0.9747, which indicated the good agreement of the proposed model to the experimental responses. Consequently, a quadratic model and a 2FI (two-factor interaction) model were developed to estimate the bond behaviour of CFRP-strengthened ECC. Based on these models, the best solution of CFRP strengthening with respect to the present study is to use 2 % PVA fibre and 5 layers of CFRP.

Conventional bricks are made off from clay with high firing temperature or from cement concrete, but these consume and emit high energy and have environment shortcoming like carbon footprint and raw materials depletion. Researchers have utilized various types of waste materials in the production of bricks to protect the environment and contribute towards sustainable development. This study presents the latest research updates on utilizing waste materials in bricks manufacturing. The study categorized into two groups based on manufacturing method: fired and unfired methods. The review of literature exhibited an obvious potential of the waste materials as partial or total replacement of conventional raw materials where the produced bricks fulfilled the standards requirements. Additional research work is required, not just in the properties and economical parts but also on educating and aware the public about the advantages of utilizing waste materials in bricks manufacturing as well as on developing codes of practices and standards. © 2018 Elsevier Ltd

Waste tires contribute badly to the environment on a huge scale as they are bulky, non-biodegradable, and prone to fire and being a shelter for mosquitos and other insects. This paper reports on a novel approach towards the development of rubberized brick by utilizing crumb rubber as the sole fine aggregate in the production of geopolymer interlocking bricks. The response surface methodology (RSM) from Design Experts software has been used to determine the numbers of trial mixes and their corresponding ingredients. A total of thirteen trial mixes were carried out and tested for compressive strength and the RSM model was developed to predict the design mix based on the targeted compressive strength. The mix design was obtained to be an 18 M for NaOH and 0.8 solution to fly ash ratio. The geopolymer interlocking rubberized bricks were then produced and tested for compressive strength, dimension, modulus of rupture, water absorption, initial rate of absorption, and efflorescence. The geopolymer interlocking rubberised bricks presented a low compressive and flexural strength and a high-water absorption capacity. The bricks were rated as non-effloresced and classified as 3rd class bricks which can be used as non-load bearing material. It is recommended to utilize nano silica in order to increase the strength of the brick. Keywords: Rubberized bricks, Crumb rubber, Interlocking bricks, Geopolymer, Response surface methodology

This paper proposes a new type of lightweight concrete called bubble concrete, which was developed by mixing concrete with high-strength hollow bodies. In the present study, concave and spherical steel hollow bodies were used not only to form multiple cavities in the concrete but also to transfer internal stresses. Through compression tests, the shape effects and distribution effects of the hollow bodies on the strength and Young’s modulus of concrete were investigated. In addition, the mechanical characteristics of the bubble concrete were simulated by nonlinear elastoplastic finite element analysis to study the stress distribution and failure mechanism. The results indicate that with the proper combination, bubble concrete can reduce its density to 1.971–2.003 g/cm3 (83.3–84.7%, compared to control concrete) and its strength reaches 27.536–28.954 N/mm2.

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.

Most Malaysian rural houses are categorized as non-engineered buildings and vulnerable to damage during events such as windstorms due to the fact that these houses lack engineering considerations. These houses are characterized by having an attached kitchen house, and many of these houses were previously damaged by thunderstorms. The current research investigated the air flow characteristics changes surrounding these houses as a result of the presence of the kitchen. The roof pitch, position, gap height, and overhang were investigated using computational fluid dynamics (CFD) simulations. The results showed that the kitchen position at the center resulted in a slight increase in the suction on the ridge of the roof; however, it significantly altered the flow pattern in the windward and leeward directions. The results also showed that the roof overhang, roof pitch, and kitchen position contributed severely to the damage of the rural house. Moreover, the highest suction occurred at the roof ridge when the kitchen was located at the center of the rural house (Cp = −2.28). Therefore, the authors believe that it is more advantageous to have a kitchen connected to the core as it reduces the pressure on the roof of the core during thunderstorm events.

This paper reports the findings of the effect of elevated temperature on the compressive strength and durability properties of crumb rubber engineered cementitious composite (CR-ECC). The CR-ECC has been tested for its compressive strength and chemical resistance test against acid and sulphate attack. Different proportions of crumb rubber (CR) in partial replacement to the fine aggregate and polyvinyl alcohol (PVA) fiber have been utilized from 0 to 5% and 0 to 2%. The experiments were designed based on a central composite design (CCD) technique of response surface methodology (RSM). After 28 days curing, the samples were preconditioned and exposed to high temperatures of 100 &deg, C, 200 &deg, C, 300 &deg, C, 400 &deg, C, 500 &deg, C, 600 &deg, C, 700 &deg, C, 800 &deg, C, 900 &deg, C, and 1000 &deg, C for one hour. Although the residual compressive strength of CR-ECC was negatively affected by elevated temperature, no explosive spalling was noticed for all mixes, even at 1000 &deg, C. Results indicated that CR-ECC experiences slight weight gain and a reduction in strength when exposed to the acidic environment. Due to the reduced permeability, CR-ECC experienced less effect when in sulphate environment. The response models were generated and validated by analysis of variance (ANOVA). The difference between adjusted R-squared and predicted R-squared values for each model was less than 0.2, and they possess at least a 95% level of confidence.

Increasing amount of nonbiodegradable wastes has postured major natural concern particularly in developing nations. The impacts of pulverized wastes, such as glass bottles (cullet), as halfway constitution of fine aggregates within the characteristics of hot blend asphalt was studied to move forward such challenge. The perspective direction of utilization of household glass wastes (cullet) is its use in structures of bituminous mineral compositions for paving. Rational structures of fine-grained bituminous mineral compositions with the inclusion of a cullet of 15−5 mm fractions are developed. The application of cullet significantly reduces the bitumen content of bituminous mineral compositions. The rational limits of cullet maintenance in fine-grained bituminous mineral compositions are set in 28–36 % wt. The shear and crack resistance of bituminous mineral compositions with the rational maintenance of cullet in the mixture meets the requirements of Russian State Standards. The high frost resistance of the developed structures (more than 100 freeze–thaw cycles) is established. The analysis of stress and strain state at various operational temperatures shows the increased deformation stability and high deformation resistance of the developed compositions.

The behavior of rubberized interlocking masonry walls is substantially influenced by the properties of the waste materials used, which makes them behave differently from conventional interlocking masonry systems. Ten each of hollow and grouted walls were constructed using rubberized interlocking bricks and then tested under compressive loading. Rubberized interlocking bricks are made using 10% crumb rubber and 56% fly ash as a partial replacement for fine aggregates and cement by volume, respectively. The structural behavior, including strength, load-deformation performance, stress-strain relations, and failure mechanisms of the tested load-bearing walls have been investigated. The results reveal the ability of rubberized interlocking masonry walls to withstand axial compressive of 3.87 MPa for hollow and 5.75 MPa for grouted specimens, which is approximately 15–20% lower than in conventional interlocking masonry walls. Web splitting, vertical cracking and face spalling were common failure modes for hollow and grouted rubberized interlocking masonry walls. In contrast to conventional interlocking walls under compressive loading, rubberized interlocking walls show increased ductility and undergo measurable post-failure loads with significant displacement due to the presence of crumb rubber, which permits a large expansion of microcracks inside the specimens after failure. Rubberized interlocking walls also tend to have large initial deflections as the bricks settle and the gaps caused by dry joints close.

An experimental study is conducted to determine the influence of secondary reinforcement on the behaviour of corbels fabricated with three different types of high-performance fiber-reinforced cementitious composites, including engineered cementitious concrete (ECC), high-performance steel fiber-reinforced composite (HPSFRC), and hybrid fiber-reinforced composite (HyFRC). Two shear span-to-depth ratios (a/d = 0.75 and 1.0) are explored. The mechanical properties of the composites in terms of tensile, compressive, and flexural strengths are investigated. Next, the structural behaviour of the high-performance cementitious composite corbels in terms of ultimate load capacity, ductility, and failure modes under the three-point bending test are investigated. The secondary reinforcement is proven to significantly affect stiffness and ultimately load capacity of all three high-performance composite corbels with an aspect ratio of 0.75. However, the secondary reinforcement was more impactful for the HPSFRC corbels, with 51% increase of ultimate strength. Moreover, in terms of damage, fewer cracks occurred in ECC corbels. HPSFRC corbels displayed the highest level of ductility and deformation capacity compared to the other specimens. The results were comparatively analyzed against the predicted results using truss and plastic truss models which provided relatively reliable shear strength.

Conventional bricks are the most elementary building materials for houses construction. However, the rapid growth in today's construction industry has obliged the civil engineers in searching for a new building technique that may result in even greater economy, more efficient and durable as an alternative for the conventional brick. Moreover, the high demands for having a speedy and less labour and cost building systems is one of the factor that cause the changes of the masonry conventional systems. These changes have led to improved constructability, performance, and cost as well. Several interlocking bricks has been developed and implemented in building constructions and a number of researches had studied the manufacturing of interlocking brick and its structural behaviour as load bearing and non-load bearing element. This technical paper aims to review the development of interlocking brick and its structural behaviour. In conclusion, the concept of interlocking system has been widely used as a replacement of the conventional system where it has been utilized either as load bearing or non-load bearing masonry system.