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Lightweight fibre-reinforced concrete integrates the advantages of lightweight aggregates with the strength-enhancing properties of fibres, resulting in a lighter composite with enhanced impact and mechanical performance. However, achieving an optimal balance between structural weight, and performance remains a challenging endeavour. This study investigates the mechanical properties, impact energy absorptions, flexural toughness, and crack resistance of lightweight fibre-reinforced concrete with the coarse aggregate entirely replaced with lightweight expanded clay aggregate (LECA). Concrete mixes containing 0 %, 0.5 %, 0.75 %, and 1.0 % Polypropylene fibre (PPF) and 10 % micro-silica were experimentally investigated. Predictions for concrete mixes with up to 2 % PPF were made using regression models developed from experimental data. The experimental and predicted results were analysed using response surface methodology. The findings reveal significant enhancements of up to 300 % and 570 % in toughness indices I5 and I10 at 1 % PPF, coupled with a 55.4 % increase in residual strength. Furthermore, an optimised slab thickness of 47 mm containing 1.73 % PPF yielded optimal impact energy absorption of 680 J and 2384 J and crack resistance of 3823 MPa and 16279 MPa at service and ultimate loading, respectively. These metrics represent improvements of 4.8, 15.2, 37, and 56 times, respectively, compared to the control samples. These substantial advancements highlight the potential of lightweight fibre-reinforced LECA concrete in engineering applications where balancing impact energy absorption, crack resistance, and structural weight is crucial. This innovative approach promises a transformative impact on the construction industry, paving the way for more efficient and resilient infrastructure.

For over three (3) decades, there has been an increase in research on energy sources from the production of oil using flexible marine risers, such as marine hoses. Marine hoses are conduits for special use as rubberized structures with hybrid polymer composites for offshore platforms in the oil and gas industry. This scientometric study uses qualitative, quantitative, and computational approaches. Data were retrieved using a research methodology that was created for this study using the SCOPUS and Web of Science (WoS) databases. This study provides a bibliometric literature review on marine hoses with an emphasis on the advancements made in the field from recent developments, geographical activity by countries, authorship histories, partnerships, funding sources, affiliations, co-occurrences, and potential research areas. The study found that the USA had the most publications, but there were fewer co-occurrences with connections outside the cluster. Due to the difficulty of adaptation, acceptability, qualification, and deployment of marine hoses in the offshore marine industry, this topic contains more conference papers than journal papers. Therefore, more funding sources and collaborations on marine hoses are required to advance the research. This study makes a contribution to scholarship on advances made in petroleum exploration and production for (un)loading hoses.

The increasing energy demand has led to more explorations in the oil and gas industry. To achieve this, marine risers and pipelines are used to convey fluid and other resources to meet the increasing demand. In recent years, hybrid flexible composite risers have become more adaptable. Flexible risers have already proven to be a popular riser solution for various floating production systems in shallow to deepwater in many parts of the world due to their good dynamic behaviour and dependability. The hybrid flexible composite riser is made up of numerous layers of plastics, flexible pipes, composites, and steel. Some innovative monitoring methods, such as Fiber Optics Bragg Gratings (FBG), are based on a clamped composite structure with embedded optical fibre. This study presents characteristics of the monitoring techniques of composite flexible riser technology. The advantages of the monitoring techniques include aiding composite riser measurements, recording data from riser deformation, improving integrity assurance, and dependability of design from stable readings. It also proposes some design approaches as guidelines that are advised, with some policy implications.

Following the rising technological advancements on composite marine structures, there is a corresponding surge in the demand for its deployment as ocean engineering applications. The push for exploration activities in deep waters necessitates the need for composite marine structures to reduce structural payload and lessen weights/loads on platform decks. This gain is achieved by its high strength–stiffness modulus and light-in-weight attributes, enabling easier marine/offshore operations. Thus, the development of composite marine risers considers critical composite characteristics to optimize marine risers’ design. Hence, an in-depth study on composite production risers (CPR) is quite pertinent in applying composite materials to deep water applications. Two riser sections of 3 m and 5 m were investigated under a 2030 m water depth environment to minimise structural weight. ANSYS Composites ACP was utilized for the CPR’s finite element model (FEM) under different load conditions. The choice of the material, the fibre orientation, and the lay-up configurations utilised in the modelling technique have been reported. In addition, the behaviour of the composite risers’ layers under four loadings has been investigated under marine conditions. Recommendations were made for the composite tubular structure. Results on stresses and weight savings were obtained from different composite riser configurations. The recommended composite riser design that showed the best performance is AS4/PEEK utilising PEEK liner, however more work is suggested using global design loadings on the CPR.

In recent times, the utilisation of marine composites in tubular structures has grown in popularity. These applications include composite risers and related SURF (subsea umbilicals, risers and flowlines) units. The composite industry has evolved in the development of advanced composites, such as thermoplastic composite pipes (TCP) and hybrid composite structures. However, there are gaps in the understanding of its performance in composite risers, hence the need for this review on the design, hydrodynamics and mechanics of composite risers. The review covers both the structure of the composite production riser (CPR) and its end-fittings for offshore marine applications. It also reviews the mechanical behaviour of composite risers, their microstructure and strength/stress profiles. In principle, designers now have a greater grasp of composite materials. It was concluded that composites differ from standard materials such as steel. Basically, composites have weight savings and a comparative stiffness-to-strength ratio, which are advantageous in marine composites. Also, the offshore sector has grown in response to newer innovations in composite structures such as composite risers, thereby providing new cost-effective techniques. This comprehensive review shows the necessity of optimising existing designs of composite risers. Conclusions drawn portray issues facing composite riser research. Recommendations were made to encourage composite riser developments, including elaboration of necessary standards and specifications.