Agusril Syamsir

3D-printed structures are an important direction in green construction, but layer-wise deposition forms interlayer interfaces that strongly influence the axial compressive performance of printed walls. This paper reviews interlayer bonding, anisotropy, strengthening strategies, and component-level load-bearing behavior of 3D-printed concrete walls within a “material–process–interface–component” framework and distils three main insights. First, anisotropy ranking is not universal. Although previous studies often report higher strength in the X-direction, anomalous cases and differences in direction definition indicate that this ranking is jointly affected by material systems and process parameters; therefore, simple deterministic statements should be avoided. Second, this review synthesizes the concept of an “optimal intervention zone” to explain why strengthening effectiveness does not increase monotonically with intervention intensity, but is influenced by interlayer bond strength, stress distribution, and reinforcement orientation. Beyond a reasonable range, new weak links may be introduced. Third, 3D-printed concrete walls and masonry structures both exhibit load-bearing behavior governed by horizontal weak planes. Masonry systems may therefore provide a useful design reference, although further development is required to reflect printed-interface characteristics. Overall, the key bottleneck is the lack of a cross-scale transfer chain from material interfaces to component performance. Cross-scale predictive models, interlayer bond testing and grading, and interface-performance-centered standardized design are important pathways toward engineering application.

In the pursuit of sustainable and resilient energy systems, smart energy infrastructure has emerged as a transformative model, rethinking the generation, management, and consumption of energy in urban settings. The progression is primarily driven by the development of hybrid roof panel photovoltaic (PV) cells, which incorporate several energy conversion methods, including photovoltaicthermal (PV/T), solar-wind, or solar-storage hybrids, to address the constraints of traditional PV systems. Conventional photovoltaic systems, although environmentally friendly and gaining popularity, are sometimes limited by variable environmental conditions, inadequate efficiency, and elevated installation or maintenance expenses. These limitations hinder their extensive incorporation into intelligent urban energy networks, which require systems that are efficient, adaptive, scalable, and economically viable. This paper critically examines the advancement of hybrid photovoltaic technologies, emphasising advancements in materials science, energy management algorithms, and architectural integration techniques. The paper utilises extensive datasets from recent case studies, computer models, and experimental validations to provide a consolidated understanding of the design, implementation, and performance of hybrid photovoltaic systems. Hybrid photovoltaic cells exhibit superior energy output, optimised thermal management, and greater load-matching capabilities, establishing them as crucial facilitators in the shift towards low-carbon urban energy solutions. Essential findings indicate that these hybrid systems markedly enhance the reduction of operational energy expenses, extend system longevity, and promote more efficient energy storage and distribution within smart grids. Furthermore, their integration facilitates decentralised energy frameworks and enhances grid resilience. The assessment continues by pinpointing significant research deficiencies and prospective avenues, including adaptive control systems, novel composite materials, and integrated monitoring frameworks, which could enhance the capabilities of hybrid photovoltaic technologies in future smart energy infrastructures.

Concrete-Filled Double-Skin Steel Tube (CFDST) columns are a cutting-edge structural option that blends the compressive qualities of concrete with the strength and flexibility of steel. This review study offers a thorough analysis of the body of knowledge on CFDST columns, concentrating on their applications, design factors, and structural behavior. A critical examination is conducted on significant elements, such as dynamic performance, fire resistance, local and global buckling, steel-concrete bonding, and load-bearing capacity. The report also highlights construction-related challenges, such as complex bonding and manufacturing processes—inefficiencies, while exploring alternatives, like implementing shear connections, advanced concrete materials, and optimum designs. According to the assessment, CFDST columns have several important advantages that make them appropriate for high-rise structures, bridges, and infrastructure in challenging conditions. These advantages include their high strength-to-weight ratio, enhanced seismic performance, and sustainability benefits. The knowledge gaps and areas that need more investigation, such as long-term durability and creative design approaches, are also discussed. To ensure that CFDST columns are widely used in contemporary construction, this study intends to direct future research, improve design procedures, and aid in creating engineering standards. The following points may improve the conclusion parameters commonly used in CFDST column studies: Column length-to-outer diameter ratio (L/Do), typically between 3 and 5, and spacing of shear connectors of approximately 50 mm to 200 mm.

With the increasing exploration of oil and gas into deep waters, the necessity for material development increases for lighter conduits such as composite marine risers, in the oil and gas industry. To understand the research knowledge on this novel area, there is a need to have a bibliometric analysis on composite marine risers. A research methodology was developed whereby the data retrieval was from SCOPUS database from 1977-2023. Then, VOSviewer was used to visualize the knowledge maps. This study focuses on the progress made by conducting knowledge mapping and scientometric review on composite marine risers. This scientometric analysis on the subject shows current advances, geographical activities by countries, authorship records, collaborations, funders, affiliations, co-occurrences, and future research areas. It was observed that the research trends recorded the highest publication volume in the U.S.A., but less cluster affiliated, as it was followed by countries like the U.K., China, Nigeria, Australia and Singapore. Also, this field has more conference papers than journal papers due to the challenge of adaptability, acceptance, qualification, and application of composite marine risers in the marine industry. Hence, there is a need for more collaborations on composite marine risers and more funding to enhance the research trend.

Pultruded glass fiber-reinforced polymer (GFRP) materials are increasingly recognized in civil engineering for their exceptional properties, including a high strength-to-weight ratio, corrosion resistance, and ease of fabrication, making them ideal for composite structural applications. The use of concrete infill enhances the structural integrity of thin-walled GFRP sections and compensates for the low elastic modulus of hollow profiles. Despite the widespread adoption of concrete-filled pultruded GFRP tubes in composite beams, critical gaps remain in understanding their flexural behavior and failure mechanisms, particularly concerning design optimization and manufacturing strategies to mitigate failure modes. This paper provides a comprehensive review of experimental and numerical studies that investigate the impact of key parameters, such as concrete infill types, reinforcement strategies, bonding levels, and GFRP tube geometries, on the flexural performance and failure behavior of concrete-filled pultruded GFRP tubular members in composite beam applications. The analysis includes full-scale GFRP beam studies, offering a thorough comparison of documented flexural responses, failure modes, and structural performance outcomes. The findings are synthesized to highlight current trends, identify research gaps, and propose strategies to advance the understanding and application of these composite systems. The paper concludes with actionable recommendations for future research, emphasizing the development of innovative material combinations, optimization of structural designs, and refinement of numerical modeling techniques.

Hybrid kenaf/glass fiber reinforced polymer composites have emerged as promising structural materials, garnering significant attention due to their unique blend of natural kenaf fibers and synthetic glass fibers. However, despite their potential, there remains a gap in the comprehensive understanding of their quasi‐static mechanical behavior, creep resistance, and fatigue performance. This paper addresses this gap by presenting recent advancements in studying these key properties of hybrid composites. Studies reveal that the combination of kenaf and glass fibers results in enhanced tensile, flexural, and impact strengths compared to individual fiber composites. Additionally, the hybridization offers improved creep resistance, with the glass fibers reinforcing the polymer matrix against deformation under sustained loads. Furthermore, investigations into fatigue properties demonstrate the resilience of hybrid composites to cyclic loading, contributing to prolonged service life in high‐stress environments. By elucidating the interplay between kenaf and glass fibers, this review underscores the potential of hybrid composites in various structural applications. The synergistic effects between natural and synthetic fibers offer a balance between sustainability, performance, and durability, making hybrid kenaf/glass fiber reinforced polymer composites a compelling choice for industries seeking lightweight, high‐performance materials in which aligns with the sustainable development goals (SDGs) especially on Goal 12. Highlights: In composite engineering, combining glass and kenaf fibers could cut production costs, yield high‐performance materials, and promote green technology. Substituting part of the glass fiber with kenaf can enhance the strength‐to‐weight ratio and promote greater biodegradability in current synthetic composites. Quasi‐mechanical properties of hybrid kenaf/glass‐based composites was enhanced by optimal stacking sequences, filler addition, and fiber treatment. Failures due to fatigue and creep can be reduced by hybridizing kenaf/glass fiber composites can prevent in polymer composite due to enhance elastic modulus. Enhanced tribological performance of hybrid kenaf/glass‐based composites due to less damage in microstructure via good interlocking of kenaf and glass in matrix.

The use of recycled concrete aggregate (RAC) in creating new concrete has gained significant attention for environmental and financial reasons. However, the compressive strength of the product concrete is hard to predict due to many variables. In this study, the compressive strength of recycled aggregate concrete was predicted using eight well-known machine learning algorithms, including support vector machine (SVM), artificial neural network (ANN), XGboost, Tree, Random Forest, Gradient Boosting, CatBoost, and AdaBoost. Every machine learning algorithm's general methodology entails gathering and analyzing input data, training the algorithm, testing the algorithm, and producing an output. A total of 419 data samples (experimental tests) were used in training and testing all the machine learning models. The results show that the best models for estimating RAC compressive strength are Neural Network, AdaBoost, and XGBoost. The other algorithms, random forest, gradient boosting, and Catboost, performed well in predicting the compressive strength of RAC, however, tree decision and SVM performed badly. The primary evaluation metrics used in this study were Mean Squared Error (MSE) and R-squared (R²), which helped determine the accuracy and reliability of the predictive models.