Comparative flexural performance of steel fibre reinforced self-compacting concrete (SCFRC) ribbed slab with different fibre provision area

The flexural performance of three SCFRC ribbed slabs with different fibre provision area were investigated in this paper; in both ribs and flange (SFWS), ribs only with additional welded mesh in flange (SFT) and in ribs only (SFR). Short hooked end fibres of 35 mm length of 1% volume fraction was blended with the flowable self-compacting concrete (SCC) were used as the material for the slabs. Slab samples of 2.8 × 1.2 × 0.2 m were constructed and loaded until failure under four- point bending. Investigation was carried out in view of the load bearing capacity, deflection, energy absorption capacity as well as the failure modes. The influence of the steel fibre provision on the strain distribution was also examined

Bending strength of steel fibre reinforced concrete ribbed slab panel / Amir Syafiq Samsudin … [et al.].

Nowadays, demands in the application of fibre in concrete increase gradually as an engineering material. Rapid cost increment of material causes the increase in demand of new technology that provides safe, efficient and economical design for the present and future application. The introduction ofribbed slab reduces concrete materials and thusthe cost, but the strength of the structure also reduces due to the reducing of material. Steel fibre reinforced concrete (SFRC) has the ability to maintain a part of its tensile strength prior to crack in order to resist more loading compared to conventional concrete. Meanwhile, the ribbed slab can help in material reduction. This research investigated on the bending strength of 2-ribbed and 3-ribbed concrete slab with steel fibre reinforcement under static loading with a span of 1500 mm and 1000 mm x 75 mm in cross section. An amount of 40 kg/m steel fibre of all total concrete volume was used as reinforcement instead of conventional bars with concrete grade 30 N/mm2 . The slab wastested underthree-point bending. Load versus deflection curve was plotted to illustrate the result and to compare the deflection between control and ribbed slab. Thisresearch showsthat SFRCRibbed Slab capable to withstand the same amount of load as normal slab structure, although the concrete volume reduces up to 20%

Preliminary investigation on the flexural behaviour of steel fibre reinforced self-compacting concrete ribbed slab / Nur Aiman Suparlan … [et al.]

A ribbed slab structure has the advantage in the reduction of concrete volume in between the ribs resulting in a lower structural self-weight. In order to overcome the drawbacks in the construction process, the application of steel fibre self-compacting concrete (SCFRC) is seen as an alternative material to be used in the slab. This preliminary investigation was carried out to investigate the flexural behaviour of steel fibre selfcompacting concrete (SCFRC) as the main material in ribbed slab omitting the conventional reinforcements. Two samples of ribbed slab were prepared for this preliminary study; 2-ribbed and 3-ribbed in 1 m width to identify the effect of the geometry to the slab’s flexural behaviour. The dimension of both samples is 2.5 m x 1 m with 150 mm thickness. The compressive strength of the mix is 48.6 MPa based on the cubes tested at 28 days. Load was applied to failure by using the four point bending test set-up with simple support condition. The result of the experiment recorded ultimate load carrying capacity at 30.68 kN for the 2-ribbed slab and 25.52 kN for 3-ribbed slab. From the results, the ultimate load of the 2-ribbed sample exceeds 3-ribbed by approximately 20%. This proved that even with lower concrete volume, the sample can still withstand an almost similar ultimate load. Cracks was also observed and recorded with the maximum crack width of 2 mm. It can be concluded that the steel fibres do have the potential to withstand flexural loadings. Steel fibre reduces macro-crack forming into micro-cracks and improves concrete ductility, as well as improvement in deflection. This shows that steel fibre reinforced self-compacting concrete is practical as it offers good concrete properties as well as it can be mixed, placed easier without compaction

Durability and performance of carbon fibre reinforced polymer-concrete bonding system under tropical climates

The existing reinforced concrete structures may require rehabilitation and strengthening to overcome defect and environmental deterioration. Fibre Reinforced Polymer (FRP)-concrete bonding systems can provide solution for the deficiencies, but the durability of the bonded joint needs to be investigated for structural reliability. This research studies the flexural performance of reinforced concrete beams strengthened with Carbon FRP and the interfacial bonding behaviour of CFRP-concrete system under tropical climate exposure. A 300 mm concrete prisms were bonded with CFRP plate and exposed for 3, 6, and 9 months to continuous natural weather, laboratory environment, and wet-dry exposure in 3.5% saltwater solution at room and 40 °C temperature. The prisms were subjected to tension and compression load under bonding test to determine the strain, stress distribution and shear stress transfer behaviour. The flexural performance was studied on 2400 mm length reinforced concrete beams strengthened with CFRP plate and fabric and exposed for six months to similar conditions as the concrete prisms without the higher temperature. The results of the bonding test showed that load transfer was fairly linear and uniform at lower load level and changed to non-linear and nonuniform at higher load level. The force transfers affected and shifted the shear stress distribution along the bonded length. The flexural capacity of the reinforced concrete beams increased between 32% and 37% and for CFRP plate and between 10% and 12% for CFRP fabrics. High interfacial stress developed near the cut-off point and decreased towards the centre of the beam. Plate-end debonding dominated the failure pattern of the beam. The combination of climate effects may have provided better curing of the bonded joints, but longer duration of exposure may be required to weaken the bond strength. Nevertheless, the tropical climate and salt solution did not yield significant bad effect on the CFRP-concrete bonding system

Performance of externally bonded reinforced concrete structures using carbon fibre reinforced polymer in tropical climate

Strengthening of existing concrete structures may be necessary in order to overcome the increase in loading capacity and also environmental effect. Durability and ductility are essential to the long-term sustainable service life of FRP material and concrete structural members with FRP reinforcement. Structural reliability and durability implies good performance of material that are able to resist degradation and capable to avoid structural damage. The strengthening of concrete structures through the use of externally bonded FRP composite system raises concern on the durability of the FRP materials at two locations. The first ones is the durability of the FRP material itself and the other one the durability between FRP material and the concrete substrate. The renewal of structural inventory is best summarized into (i) rehabilitation that include the application to repair, strengthening and retrofit structures and (ii) new construction with all FRP or new (Van Den Einde et al., 2003). Tropical climate of countries which experience high average annual temperature, humidity, rainfall and relatively constant ultra violet ray (UV) may have detrimental effect on the usage of FRP composite either externally or internally retrofitted. The rainy season or the most rainfall is experienced by East Malaysia in the October through February with annual rainfall of 5080 mm compared to 2500 mm of annual rainfall for the Peninsular Malaysia. Even tough, the temperature is quite consistent throughout the year, the temperature records in Malaysia for the last fifty years has shown a warming trend (Zhao et al., 2005). The amount of information on the durability of FRP subjected to environmental condition especially in the tropical climate environment is still very limited in the literature. Concluded researches show inconsistencies in the results on the degradation effect. It is crucial to study the tropical climate effect of using FRP and its matrix material in structures element in order to gain acceptance in a country which is experiencing tremendous wet and dry cycle through rain, moisture and dry season. This is essential because many of the applications of FRP as strengthening or repair materials are for outdoor environment. However, there is another concern of using FRP as external strengthening materials which is interfacial fracture along the bonded joints that can limit the strengthening performance of FRP materials. It is essential for the long term behavior of the structural bonded joints in civil engineering structures be guaranteed between 50 to 100 years for the acceptance of this bonded system in the construction industry (Täljsten, 2006)

Flexural behavior of externally bonded CFRP - reinforced concrete beam exposed to natural weather

The current research concerns with the effect of natural tropical climate on the flexural and interfacial bonding behavior of an externally bonded reinforced concrete beams by using carbon FRP. The various components of tropical climate combines with saltwater exposure may influence the structural and durability performance of FRP-epoxy-concrete system over long period of time. The results of FRP strengthened and conditioned beams demonstrated significant flexural improvement compared to control beams. The failure and the development interfacial stress in the bonded system were also evaluated

Flexural behaviour and punching shear of selfcompacting concrete ribbed slab reinforced with steel fibres

This paper investigates the effects of steel fibres as a replacement to the conventional reinforcement under flexural behaviour and punching shear in self-compacting (SCC) ribbed slab reinforced with steel fibres. Four ribbed slabs with similar dimensions of 2.8 m length × 1.2 m width and 0.2m thickness were constructed. Two of the samples were considered as control samples (conventionally reinforced with reinforcement bars and welded mesh) while another two samples were fully reinforced with 1% (80 kg/m3) volume of steel fibres incorporated to the SCC mix. For the flexural behaviour study, the ribbed slab samples were subjected to two line loads under four point bending. Meanwhile, for the punching shear analysis, the ribbed slab samples were subjected to a point load to simulate loading from the column. The analysis of the experimental results displayed that steel fibres incorporation had been found to effectively delay the first crack occurrence under both flexural and punching shear. The steel fibre replacement has been proven to be able to sustain up to 80% and 73% of the ultimate load resistance for flexural and punching shear, respectively, in comparison to conventionally reinforced ribbed slab structure. The visual observation carried out during the experiment exhibited similar failure mode for both steel fibre reinforced and control samples. This was observed for both flexural and punching shear samples. Overall, it can be concluded that the steel fibres had displayed a promising potential to effectively replace the conventional reinforcements

A bibliometric analysis on the relevancies of artificial neural networks (ANN) techniques in offshore engineering

AbstractRecently, the use of artificial neural networks (ANN) in the offshore exploration and production industry to optimize decision-making and reduce costs and non-productive time have been increasing. Despite this trend, there have been only 11 reviews of ANN in offshore engineering published on the Scopus database. Therefore, this article aims to provide an update on the relevance of ANN in offshore engineering over the past 18 years (2005–2023) through a bibliometric analysis using Excel and VOS Viewer software. This analysis highlights the yearly increase in publications related to ANN implementations in offshore engineering and identifies the most cited publications, citation network analysis, authors, keywords, journals, institutions, and leading countries. The objective of this bibliometric analysis is to assist subsequent research and collaboration in this field by shedding light on ANN’s potential and identifying areas for further application. The identified cluster area publications encompass a range of topics, including drilling systems and the assessment of pipes. Furthermore, the significant fourfold increase in publications since 2005 indicates a growing interest among researchers in adapting ANN for various applications within this field. This could lead to further advancements, innovations, and improved solutions to promote collaboration and knowledge-sharing among researchers in this domain