Journal of Construction

Comparison of structural responses for tall buildings with varying twisting rates and core wall configurations

2024-10-29T03:01:39+00:00

This study aims to compare the structural responses of tall buildings (TBs) with different twisting rates and core wall configurations to investigate their effect under various loading conditions. The study examines three groups of TBs with varying core wall layouts: hexagonal shape for group A, circular shape for group B, and square shape for group C. Three models were constructed for each group, with twisting angles of 0°, 90°, and 180°. The study initially compares the nine different models’ natural periods of vibration and modal mass participation ratios. The towers’ wind and seismic responses for each model under wind, response spectrum (RS), and nonlinear time history (NTH) analysis are also presented. The wind, RS, and NTH analysis outcomes regarding the structural system (natural periods, drift ratios, story shear forces, and overturning moments) and members (shear forces and bending moments on columns and walls) have been compared. Finally, a multiple-criteria decision-making algorithm was used to determine the optimum model based on the investigated responses. The findings indicate that the core wall layout has a more significant influence on the response of TBs than the twisting rate. Specifically, a building with a hexagonal core wall system and 0-degree twist is identified as the optimal configuration. Although its effects are less significant than seismic forces, wind analysis reveals that twisting in buildings slightly reduces the natural period and drift ratios. This study emphasizes the impact of TBs configurations and twisting rates on both wind and seismic responses.

Key influencing factors of 6D BIM to enhance the sustainability performance of residential BIPV in China

2025-06-02T07:43:16+00:00

6D building information modeling (6D BIM) has been proposed as a sustainability dimension in BIM technology. It serves as a life-cycle sustainability assessment tool and an important method for decision makers and designers to make informed decisions in sustainable design and facility management. However, there is currently a lack of comprehensive evaluation of the key influencing factors of 6D BIM in residential Building-Integrated Photovoltaic (BIPV) systems. Previous studies have typically examined BIPV performance or BIM-based sustainability workflows in isolation, lacking a comprehensive analysis of how 6D BIM enhances BIPV sustainability throughout the building lifecycle. This study aims to identify the core influencing factors of 6D BIM in BIPV systems and analyze their impact on sustainability performance indicators. To this end, this study used a systematic literature review method to retrieve research literature related to 6D BIM and BIPV from the past decade (2014-2024) from Scopus and Web of Science databases and applied the PRISMA method to screen and analyze 111 highly relevant literature. The results show that the keywords of BIPV-related research have been continuously updated in the past decade, showing the rapid development of 6D BIM in the field of sustainable buildings and its potential in building energy management. Based on the sustainability of BIPV, the study identified five key factors that affect the application of BIPV in sustainable systems: economic and cost factors, policy and social factors, geographical and meteorological factors, design and performance factors, and operation and maintenance factors. In addition, according to the sustainable performance of BIPV, 6D BIM is used as an enhancement factor to improve the sustainability of BIPV. The results of this study provide new insights into the application of 6D BIM in the field of BIPV and provide a scientific basis for stakeholders to develop more efficient implementation strategies.

Effects of steel slag fineness and MEROS ash on GGBFS-based geopolymers

2025-09-07T21:34:31+00:00

In this study, magnetic and non-magnetic steel slag (SS) and ground granulated blast furnace slag (GGBFS) with two different fineness levels were utilized in the production of geopolymers. In the synthesis of geopolymers, a triple alkaline activator comprising MEROS® ash (MA), a by-product of the iron and steel industry, in combination with Na₂SiO_3(aq) and NaOH, was employed. Workability was conducted on fresh geopolymers, while compressive strength, water absorption, shrinkage, and microstructural analyses were performed on hardened geopolymers. The experimental findings demonstrate that the physical, mechanical, and microstructural properties of geopolymers produced with coarse (<1 mm) and fine (<125 µm) SS particles were comparable; however, the grinding process for coarse SS was approximately 9.6 times more energy-efficient than that for fine SS, thereby demonstrating a significant advantage in energy savings. The presence of magnetic and non-magnetic steel slag, with particle sizes smaller than 1 mm, has been shown to reduce shrinkage in geopolymers. The MA significantly enhances compressive strength and workability. The highest compressive strengths were obtained on the Mc2s, which was produced using magnetic steel slag with a size of less than 1 mm and 5% sintering ash, reaching 48.85 MPa at 2 day and 62.0 MPa at 28 day. The microstructure analysis indicates that geopolymer gels, such as C-S-H and C(N)-A-S-H, contain sulfur forms derived from the MA. This work differs from previous SS/GGBFS geopolymer studies by systematically comparing magnetic and non-magnetic steel slag at different fineness levels and by quantifying the energy savings achieved through the use of MEROS® ash in a ternary activator system.

Crack detection on asphalt runway using unmanned aerial vehicle data with non-crack object removal and deep learning methods

2025-06-03T09:00:08+00:00

Unmanned aerial vehicles are extensively utilized for image acquisition in a cheap, fast, and effective way. In this study, an automatic crack detection method with non-crack object removal and deep learning-based approaches are developed and tested on images captured by unmanned aerial vehicle. The motivation of this study is to detect either a crack exists or not in the asphalt-runway. The novelty of this study lies in integrating a non-crack artifact removal process with six classical edge detectors and comparing the resulting performance with four lightweight CNN models on the same UAV-acquired runway image dataset, enabling a unified evaluation of classical and learning-based approaches. For deep learning-based approach, four lightweight CNN models, namely GoogleNet, SqueezeNet, MobileNetv2, and ShuffleNet, are trained and the best accuracy of %87.9 is obtained whenever GoogleNet model is used. For the non-crack object removal approach, exclusion of non-crack objects from the images is the first step, where crack-detection which makes use of edge-detection techniques is the latter. In the study, Sobel, Prewitt, Canny, Laplacian of Gaussian, Roberts and Zero Cross edge detection algorithms are examined and their success rates in detecting cracks are comparatively presented. With sensitivity=0.981, specificity=0.744, accuracy=0.917, precision=0.912 and F-score=0.945 values Canny algorithm performs significantly better than others in detecting the cracks. This study provides enough evidence for the practicability of automated crack detection on unprocessed digital photographs by the results of the study conducted on asphalt runway.

Practical applications of mortars using cattle bone ash as partial cement replacement

2025-02-18T18:02:59+00:00

In this study, commercially available cattle bone ash (CBA) was utilized as a partial cement replacement to evaluate its near-term and practical applicability in mortar production. CBA was incorporated into mortar by replacing Portland cement in 5% increments, up to a maximum of 30%. The research assessed both the fresh properties (such as table flow) and the hardened properties (including density, water absorption, compressive strength, drying shrinkage, and ultrasonic pulse velocity) of the mortar. The findings showed that while increasing CBA replacement rates generally led to a decline in mortar properties, replacements up to 10% had negligible effects. Specifically, mortar with a 10% CBA replacement exhibited a density only 0.1% lower than that of standard mortar, a 7-day compressive strength 2.3% higher, and a 28-day compressive strength 3.8% lower. Furthermore, even with 30% of Portland cement replaced by CBA, the mortar still met industry standards for both 7-day and 28-day compressive strengths, making it suitable for applications in brick and flooring. These findings highlight the feasibility of using CBA as a supplementary cementitious material and provide practical guidance for its rapid field application.

Investigation of creep behavior of various types of reinforced concrete haunched beams

2024-07-08T13:56:08+00:00

In this study, the influence of creep was comprehensively investigated for both prismatic and non-prismatic reinforced concrete beams using finite element analysis, while taking a prior experimental study into consideration. The research was conducted in two stages. In the first stage, the reliability and accuracy of the finite element modeling approach were assessed, and it was concluded that this method is suitable and effective for examining the creep behavior of reinforced concrete beams. In the second stage of the research, a comprehensive parametric study was conducted to determine the effect of each parameter (such as load values, load types, compressive strength, tensile reinforcement ratio, water-cement ratio, aggregate-cement ratio, relative humidity, and shear span-to-depth ratio) on the creep behavior of both prismatic and non-prismatic beams. The results indicate that creep deformation is more pronounced in non-prismatic beams, where the inclination angle notably influences the structural response. Consequently, the load-to-capacity ratios were adjusted to account for the increased creep effects.

The earthquake performance assessment of a reinforced concrete building with nonlinear static and dynamic analyses

2025-04-15T08:57:43+00:00

In this study, the earthquake performance evaluation of a 4-storey residential building was investigated. The residential building was designed according to studies on Türkiye’s building stock and the Turkish Earthquake Code 1997 (TEC-1997). The building was considered as an existing building, and its earthquake performance was evaluated according to the Turkish Earthquake Code 2007 (TEC-2007) and the Turkish Earthquake Code 2018 (TEC-2018). Pushover (POA) and nonlinear time history (NTHA) analyses, which are given in TEC-2007 and TEC-2018, were used in evaluating the earthquake performance of the building. The main purpose of the study is to compare both earthquake codes and analysis methods. The study is valuable and original because it uses a building that represents Türkiye's low-rise building stock and conducts a detailed performance evaluation according to different codes and methods. The performance of the building was evaluated under the design earthquake. The analyses of the structural system were accomplished by using SAP2000 software, incorporating inelastic material behavior for concrete and steel. The software of RESPONSE2000 was used for sectional analyses of the structural system and the moment-curvature curves. Ground motion records were taken from the PEER Ground Motion Database, and the records were edited with the help of SEISMOSIGNAL software. The numerical results were given in tables and figures comparatively and discussed. It was determined that TEC-2018 is safer than TEC-2007 in terms of determining ground motion records and damage limits of the structural system elements. Moreover, the results showed that when POA and NTHA were compared, although NTHA provided more realistic results, POA can also provide acceptable results.

Effect of thin fiber-concrete jacketing on the resilience of damaged RC columns

2024-09-23T02:08:35+00:00

This study investigates the behavior of reinforced concrete (RC) columns strengthened with RC jacketing under cyclic loading. Three full-scale specimens were tested, three of which were subjected to a constant vertical force and an alternating cyclic horizontal force until failure. The specimens were strengthened using three types of concrete: ordinary concrete (OC), steel fiber concrete (SFC), and polypropylene fiber concrete (PPFC). The bearing capacity, ductility, and failure mode of the columns were analyzed and compared. By using high-strength concrete, the thickness of the jacketing was reduced to 50 mm, which limits the negative effects of increased sections on the seismic response of the columns. The results show that the use of steel and polypropylene fibers improves the bearing capacity, delays the appearance and propagation of cracks, and extends the time to failure. This study provides valuable insights into the performance of RC columns under cyclic loading and the effectiveness of RC jacketing for their strengthening.

Laced and normal reinforced concrete beams under reverse cyclic loading: a numerical investigation and analysis

2025-02-17T15:30:26+00:00

This research uses numerical analysis to evaluate the ultimate load-carrying capacity and deflection behaviour of reinforced concrete (RC) 90 and laced reinforced concrete (LRC) 45 beams under high reverse cyclic loading conditions. Due to practical limitations, this field has not been explored experimentally. The beams were modelled using ANSYS employing sophisticated nonlinear material models, such as the Mene-trey-William model for concrete to take cyclic loading effects into account and a tangent modulus approach for reinforcing steel to predict post-yield behaviour. The analysis revealed that LRC 45 outperformed RC 90, exhibiting 30% less deformation and 18% higher maximum principal stress at 500 kN, demonstrating its enhanced stiffness and structural integrity. Additionally, LRC 45 exhibited the highest ultimate load (137 kN) and lowest deformation (12.86 mm) among the tested beams, with an average ductility factor of 2.08, making it the most suitable for dynamic and seismic applications. The systematic assessment of ductility, energy absorption, and failure mechanisms under a well-designed cyclic loading procedure and the verification of numerical findings against experimental data represent the uniqueness. The study's innovative use of cyclic and monotonic loading methods in conjunction with thorough stress-strain analysis offers insightful information on the robustness of reinforcement setups, allowing more precise forecasts of beam performance in dynamic real-world situations.