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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 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.

Severe damage or collapse of reinforced concrete dapped-end beams (RC-DEBs) may occur during the service life. The collapse of the Concorde overpass structure in Laval, Quebec, Canada, in 2006 revealed the causes of collapse, i.e., insufficient shear strength (no stirrups), misplacement of hanger reinforcement, etc. In addition, the inspection report of RC half-joint bridges in England until 2018 expressed that damages or failures of half-joint structures can be attributed to the poor condition of structures or non-compliant reinforcement detailing. These conditions exhibited how important it is to understand the proper detailing of dapped-end reinforcement. To date, some studies have performed investigations on the effect of inadequate dapped-end reinforcement on the structural behavior of DEBs. However, the results of the research to date were not yet complete enough to disclose the role of each group of dapped-end reinforcement in resisting the working load. Therefore, this study was carried out to investigate the main role of each group of dapped-end reinforcement separately on the structural performance of RC-DEBs. Eight large-scaled RC-DEBs (with sizes of 1800 mm length, 120 mm width and 250 mm height) were prepared, cast and cured. All DEB specimens were tested under the three-point loading up to failure. To localize the effect of shear failure, the shear span-depth ratio (av⁄d) of 1.43 was set. Test results exhibited that arrangement of a specific group of dapped-end reinforcement separately affects the structural performance of DEBs significantly. The diagonal reinforcement (DR) group was found to be more effective than the vertical hanger reinforcement (HR) group. The failure load capacity of the DR group (DEB-18) achieved 0.29 times that of the control beam (DEB-3). Meantime, the nib flexure reinforcement (NFR) group demonstrated the most important role in the structural performance of DEBs compared to other dapped-end reinforcement groups. The failure load capacity of the NFR group (DEB-39) reached 0.62 times that of the control beam, while rupture deflection of the NFR group also exhibited the highest value than other groups, i.e., 0.62 times that of the control beam. In addition, analysis results of rosette strain gages (RSGs) data indicated that regions near to re-entrant corner and its vicinity experienced the highest stress concentration factor (SCF) compared to other places of the beams. These regions were more susceptible to experiencing the first crack, progressive crack, damage or failure first than other regions of DEBs. The greater the value of SCF, the greater the probability of collapse occurring in the related structural elements, which is also followed by a lower failure load capacity. DEB-1 (without dapped-end reinforcement) has the highest SCF (205.68), and the lowest failure load capacity (12.58 kN), whilst DEB-3 (with the complete dapped-end reinforcement) has the lowest SCF (79.62), but the highest failure load capacity (105.26 kN). Obviously, DEB-3 can withstand the working load properly. Its adequate dapped-end reinforcement is able to accommodate and distribute the high stress flows in the dapped-end region properly, which causes the SCF value to decrease.

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.

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 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.

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.