bluuebunny/crossref_metadata_2025_split huggingface dataset:
Robust mechanical models for shear and punching strength of concrete slabs
Authors: Broms Carl Erik 
Published: November 2024

AbstractThe mechanical models in this paper are based on the nominal concrete tensile strength that is considered to be the average strength along a 150 mm long brittle failure crack. Fracture Mechanics principles are applied for addressing the size effect of brittle failures; increasing member size leads to decreasing failure stress. The shear force is assumed to be carried by the compression chord of the slab and by aggregate interlock along part of the initial shear crack. Shear failure occurs when the aggregate interlock reaches its failure force that is assumed to be constant for effective depths larger than 1.0 m. The slab outside the initial shear crack around the column in a flat slab is assumed to be suspended into the stable inverted pyramid above the column. Punching failure occurs when the suspension force fails. These failure modes are used for validation of the provisions for shear and punching in the new version of Eurocode 2 (EC2). It is found that EC2 still underestimates the size effect and the code also incorrectly claims that punching failure is related to shear failure. Corrections of these two cases are proposed in the paper. A formula for design of shear reinforcement for flat slabs is proposed where iteration is not required. The paradox that brittle punching failure can cooperate with flexible shear reinforcement is explained. An additional formula is derived that gives a flat slab such large ductility that brittle punching failure can be considered as eliminated.
Assessment of impaired reinforced concrete dapped‐end beams: An analytical approach
Authors: Abeysingha Tharumini , Padmasiri Pawani , Yapa Hiran 
Published: November 2024

AbstractReinforced concrete dapped‐end beams (DEBs) represent a unique structural type with the presence of recessed ends. The beam configuration is ideal for structural connections. However, the recessed area is structurally a disturbed region, and is vulnerable to embedded reinforcement deterioration. This study explored the potential of strength assessment of impaired DEBs via an analytical approach. A kinematics based model (KBM) was opted, and it was subjected to significant modifications to account to suit with distinct structural defects that were common to DEBs. The extended model (EKBM) was validated using experimental results available for eight beams. Both the load and failure mode predictions from the EKBM were found to be more accurate than those from the KBM, where the EKBM prediction offset was within a fair range of −23% to 15%. Furthermore, a parametric analysis was carried out to investigate the sensitivity of shear reinforcement deficiency and of reinforcement corrosion in the joint region on the beam load capacity. It revealed that the first two shear links were the most critical links. The load reduction was linearly proportional to the area reduction of reinforcement due to corrosion, however, the trend deviated from that at some combined deficiencies. The corroded reinforcement length was rather insensitive to the resulting beam strength.
Driving the Future: Unveiling Innovative Business Models for Shared Automated Mobility Services
Authors: Berrada Jaâfar , Hassan Mahdavi S. M. , Quaranta Romina , Rodríguez Paola , Ferran Victor , Weidenauer Jenny 
Published: November 2024

AbstractAutomated vehicles are becoming more and more likely as they offer promising solutions to improve urban mobility: dispatching vehicles on roads to minimize congestion, reducing accidents, increasing savings of travel time, improving the transit level of service and reducing operating costs of public modes, thus limiting public subsidies. However, these potential positive externalities are not a sufficient condition for their deployment's success. A viable Business Model has to be developed. This paper aims to provide a better understanding of the emerging Business Models in shared Cooperative, Connected and Automated Mobility (CCAM), through analysing the experiences and lessons learned from two pilot sites within the SHOW project: Les Mureaux (France) and Monheim am Rhein (Germany). In particular, a series of interviews have been conducted with mobility experts from both sites and conditions to achieve the viability whilst, later, the scalability of Business Models were discussed. Results revealed that to make automated transport services successful, several adjustments to traditional Business Models are necessary in terms of costs structures, required resources, and key partnerships. The viability and scalability are also sensitive to the costs of vehicles and supervision as well as to the maturity of automation technology.
Remote Supervision Strategies for Automated Vehicles Fleets: Three Real-Life Operational Case Studies
Authors: Cornet Henriette , Pavlakis Sofia , Levassor William , Morael Nicolas 
Published: November 2024

AbstractPublic Transport Operators (PTOs) are crucial actors in developing and deploying shared automated mobility services with their role of ensuring service quality, passenger safety, and cost-effectiveness. This chapter underscores the pivotal role of remote supervision in facilitating the seamless operation of automated vehicle fleets from the point of view of PTOs. Drawing from real-life deployments of the EU-project SHOW (GA No 875530) and other initiatives, it highlights the necessity of learning from everyday situations to enhance operational efficiency and safety. Additionally, the vision for scalable supervision centres tailored to higher levels of automation is outlined, along with the imperative for standardization at the regional level to be able to scale the integration of automated vehicles into future public transport systems.
Real-Life Automated Public Transport Operations at the SHOW German Mega Site—Experiences and Lessons Learned
Authors: Flötteröd Yun-Pang , Karnahl Katharina , Pavlakis Sofia , Holdermüller Anja , Ochs Sven , Zofka Marc René , Dietl Kai , Mook Mitja 
Published: November 2024

AbstractAutomated shuttles promise a solution to achieve sustainable mobility and meet the manpower issue in public transport, and are expected to extend public transport service coverage and improve riding comfort. The piloting activities at three German mega sites successfully demonstrated fixed and non-fixed mobility services and the technical possibilities to let shuttles move without a pre-defined virtual track and cope with a ride-booking application. Results show that the shuttles operated with promising performance. In total, in the EU project SHOW (GA No 875530), approximately 107,000 km and 40,000 passengers were respectively travelled and transported by twelve (12) automated shuttles. This chapter explicates the technical preparation, shares the collected experiences and proposes recommendations.
Autonomous Bus Depot Management: Operator’s Lessons Learned and Cost Analysis Perspective
Authors: Fernández César Omar Chacón , Balaguer Sergio Fernández , de la Iglesia Lucía Isasi , Espinar Borja Gorriz 
Published: November 2024

AbstractThis study delves into autonomous bus depot management at EMT Madrid, the Madrid Public Transport Company, within the Horizon 2020 SHOW project (GA No 875530). Its aim is to boost operational efficiency and optimize resource usage, particularly by addressing unproductive hours for bus drivers. It examines the technical feasibility of automating manual depot tasks like vehicle charging, cleaning, and parking through advanced sensor technology and control systems. The pilot at Carabanchel bus depot involved automated vehicles (AVs) with perception sensors, control mechanisms, and centralized decision-making units, testing services like internal transport, autoparking, and teleoperation. Over eleven months, the AV fleet performed successfully without incidents. The findings indicate automation's promises in reducing operational costs and enhancing resource utilization, though, challenges like initial investments, technical constraints, and regulations persist. Recommendations are made to foster public–private collaboration for innovation in public transport and for market development.
Field-Driven Lessons Learned for Delivery Robots Logistics Operation in Urban Environment
Authors: Malisetty Venkata Akhil Babu , Patatouka Elena , Raptis Odisseas , Antonakopoulou Anna , Amditis Angelos , Silani Enrico , Cepolina Elvezia Maria 
Published: November 2024

AbstractIn the city centre of Trikala, Greece, a real-life logistics service was operated with a fleet of 5 droids on a public route in the urban pedestrian area in the context of the SHOW project (GA No 875530). It took place from December 2022 to the end of February 2023. The droids are small automated vehicles missioned to carry out indoor and outdoor logistic services in pedestrian-centric environments. The logistics service that operated in Trikala was of two types: (a) a multi-stop parcel delivery service from the depot to the shops and (b) a parcel collection service from the shops to the depot. The current manuscript describes the solutions implemented and the challenges faced by the droids while performing last-mile deliveries. The manuscript concludes with suggestions from experience for new implementations of logistics services operated by automated vehicles. These include the advice to not underestimate the difficulty of integrating radically new vehicles into existing logistics services; the importance of having the trust and support of the population and the need for data network stability.
Effect of Mesoscopic Heterogeneity of Concrete on the Macro-mechanical Behavior
Authors: Lin Qindong , Feng Chun , Yuan Jianfei , Jiao Wenjun , Gan Yundan 
Published: November 2024

AbstractConcrete is a typical heterogeneous and multiscale material, and the macro-mechanical response is affected by the meso-scale geometric structure and mechanical parameters. Based on the continuum-discontinuum element method, this study conducts the numerical simulation and quantitively studies the change trend of macro-mechanical response with the different mesoscopic heterogeneity. First, a full-time numerical simulation is conducted, and the elastic modulus and cohesive strength at the meso-scale are assumed to obey the Weibull distribution. Then, the change trend of macro-mechanical parameters is studied. Finally, the change trend of crack evolution characteristic is studied. The results show that the macro-elastic modulus and macro-peak stress gradually increase with the increase of shape parameter k, and the growth rate of macro-mechanical parameters gradually decays. The difference in the shape parameter k causes the value of crack ratio to change, while the change trend of crack ratio-strain curve is similar. As the shape parameter k increases, the final value of crack ratio first decreases and then increases, and the final value of crack ratio when k = 15 is the smallest.
Experimental Study on Splitting Strength of Nano-active Powder Concrete
Authors: Bao Hailing , Ji Xiaofeng , Xu Peibao 
Published: November 2024

AbstractAiming at the problem of weakening mechanical properties of conventional concrete due to damage, the present paper studies the effect of nano-active powder on the splitting strength of concrete before and after damage. The nano-active powder concrete was prepared by adding 1.5%, 2.0% and 2.5% nano-silica (NS) and nano-zirconia (NZ) respectively. Through the splitting test before and after the damage of the sample, the self-healing performance of the sample was studied with the recovery rate of the splitting strength as the index. The results show that nano-active powders NS and NZ can increase the splitting strength and its recovery rate. Compared with the control group concrete, the addition of nano-active powder effectively improved the recovery rate of concrete splitting strength, and the optimal content of nano-active powders NS and NZ are 1.5% and 2.0%, respectively. This study deepens the understanding of mechanical properties of nano-concrete.
Dynamic Characteristics Test and Microstructure Analysis of Silt Soil Improved by Curing Agent
Authors: Lu Qi , Ma Yongzhen , Liu Ganbin , Ni Fuxin 
Published: November 2024

AbstractWith the acceleration of urbanization, the output of construction sludge and waste mud is increasing. Its transportation cost is high and there are potential safety hazards. Therefore, it is necessary to seek effective disposal and utilization methods. Aiming at the silt soil with high water content, the developed YB100 powder curing agent was used to improve the properties of silt soil, and the effects of dynamic properties and water stability of the cured soil were studied by curing agent dosing, surrounding pressure, and dynamic stress ratio. The microstructure of the cured soil was analyzed by SEM scanning electron microscopy to reveal the curing mechanism. The results showed that: the dynamic elastic modulus of the cured soil specimens increased from about 60 MPa to about 150 MPa when the amount of curing agent was increased by 0, 2, 4 and 6%; with the increase of curing agent content, the damping ratio changed less during vibration and the curve was flatter; after 24 h of water immersion, the dynamic elastic modulus of the specimens decreased by about 15–20% and the damping ratio had some growth, and with the dynamic stress ratio. With the growth of dynamic stress ratio, the weakening of dynamic elastic modulus of the specimen is not obvious, and the change of damping ratio weakly decreases less; SEM photos show that the cured soil particles are agglomerated, and the pore space is greatly reduced, because the curing agent produces hydration reaction with water in the silt soil, and the resulting gelling material improves the strength of the soil, and at the same time the complexes generated by the reaction with the soil strengthen the stability of the soil.
Numerical Analysis of Soil-Rock Mixture Subgrade Based on High Density Resistivity Surveys
Authors: Chen Jiangong , Lou Diming 
Published: November 2024

AbstractA new method to obtain the distribution of rock stone in RSM subgrade by high density resistivity surveys is proposed. Using image processing technology, the true resistivity image could be transformed to a vector format which can imported into finite element software. The finite models of RSM subgrade are established based on the vector image. The RSM subgrade bearing capacity and differential settlement under foundation’s load are analyzed. Numerical analysis result shows that the bearing capacity of RSM subgrade is bigger than the soil subgrade. The differential settlement is effected mainly by subgrade stiffness under two corners of the foundation and the location of the interface of rock and soil.
Safety Analysis of Concrete Arch Dam Considering the Shear Action of Contraction Joints
Authors: Miao Zhichao , Liu Guohua 
Published: November 2024

AbstractIn this paper, taking an extra-high arch dam as an example, the simulation of the stress, deformation and overload failure of arch dam is carried out to investigate the effect of the shear strength of contraction joints on the safety of the arch dam based on the nonlinear trial load method. The numerical simulation results show that the overload safety factor of the arch dam decreases significantly with the decrease in shear strength of contraction joints. The maximum tensile stress of the arch dam is reduced when the shear strength of the contraction joints is reduced by 30% compared to the strength of the dam material. The results provide a reference for the design of the mechanical properties of the contraction joints.
The Mix Proportion Optimization Design of Coal Gangue Pervious Concrete
Authors: Xia Junwu , Luo Chao , Xu Enlai 
Published: November 2024

AbstractIn order to improve the strength and permeability of coal gangue pervious concrete, an optimized mix design was conducted. An orthogonal experiment was employed to study the variations of compressive strength and permeability coefficient of coal gangue pervious concrete under the influence of aggregate particle size, water-cement ratio, designed porosity, and dosage of permeable admixture. After obtaining a relatively optimal mix proportion, further discussions were carried out by restricting the values of compressive strength and permeability coefficient to determine the appropriate range for the excess paste content ratio, total porosity, and effective porosity, resulting in the determination of the optimal mix design. Results indicated that the compressive strength reached its maximum at an aggregate particle size of 9.5–16 mm, with minimal impact on the permeability coefficient. As the water-cement ratio increased, the compressive strength gradually increased, while the permeability coefficient slightly decreased within the range of 0.25–0.29, and decreased by 60% within the range of 0.29–0.31. With the increase of designed porosity, the compressive strength gradually decreased, while the permeability performance gradually enhanced.
Research on Axial Tensile Mechanical Properties of Early-Strength High Ductility Cementitious Composites
Authors: Duan Wenhong , Yuan Jiaquan , Xiong Li , Jiang Weihong , Li Huimei , Mou Lin , Yang Xiaohua , Huang Xiaomin , Xu Weibing , Yang Kun 
Published: November 2024

AbstractCement concrete is widely used in pavement, bridge decks and expansion joint anchorage zones. It is prone to cracking, potholes, spalling and other diseases during use. Cement-based repair materials generally have problems such as a long curing period, low bonding strength with existing concrete, and insufficient mechanical properties. Given this, this paper proposes an early-strength high-ductility cement composite material with the goal of short curing age, excellent tensile mechanical properties and relatively low price. The tensile mechanical properties of the composite material at different ages were tested, and the tensile constitutive model of the composite material was proposed. The results show that when the fly ash content is about 50 wt.%, the PVA fiber content is about 2%, and the sand-binder ratio is 0.36–0.50, the tensile properties of the early strength high ductility cement composite material at each age are better. Under the condition of optimum mix ratio, the tensile strength of 1, 3 and 28 d of early strength high ductility cement-based composites reached 4.58 MPa, 4.67 MPa and 4.64 MPa respectively, and the strain corresponding to 0.8 times of peak stress in softening section could reach 2%.
Investigation of Dynamic Response of Concrete Slab Under Air Blast Loading
Authors: Lin Qindong , Feng Chun , Gan Yundan , Yuan Jianfei , Yang Ying 
Published: November 2024

AbstractThe dynamic response of concrete components under blast loading is of great military and social importance. Based on the continuum-discontinuum element method and fluid–structure coupling algorithm, the dynamic response of concrete slab is simulated and analyzed. First, a full-time numerical simulation is conducted. Then, the displacement and crack characteristics of concrete slab are analyzed quantitatively. The result indicates that the displacement is distributed in a circular pattern, and the maximum value is located at the center of concrete slab. The crack ratio increases gradually with the growth of time, while the growth rate is not a constant value. The fracture type of concrete slab includes tensile fracture and shear fracture, the interface at the center mainly undergoes shear fracture, and a small number of interface on the outside of cracked region suffers tensile fracture.
Research on Cumulative Damage of Quasi-Static Reinforced Concrete Short Columns with Low Cycle Fatigue
Authors: Zhou Hongyu , Guo Juxin , Tang Qi , Wang Haoda 
Published: November 2024

AbstractColumns are the main load-bearing elements in many structures, but with the advancement of service time, damage to reinforced concrete columns before reaching their design service life occurs from time to time. In this experiment, the cumulative damage of reinforced concrete short columns is investigated by using the research method of proposed static structural test. Through the low-week fatigue proposed static test of reinforced concrete short columns, the changes in the process are analyzed, and the changes in physical quantities such as cracks, strains, and deflections are recorded to study the shear damage characteristics of fatigue of reinforced concrete short columns, the damage mechanism, and the mechanical properties of the members such as the load carrying capacity after the damage.
Study on the Damage Evolution Law of Railway High Pier of New Replaceable Components Under Near-Fault Ground Motion
Authors: Zhang Xudong , Xia Xiushen , Zhang Heng 
Published: November 2024

AbstractIn order to improve the energy dissipation effect of the connection components of steel truss joints and optimize the arrangement of the components, a new replaceable component railway pier structure was proposed, referring to the transmission tower structure. The new pier consists of four pier columns and the steel truss connection system between the columns. Based on the OpenSees platform, a dynamic analysis model of the new railway pier was established. 56 seismic records were input, and incremental dynamic analysis (IDA) was carried out to investigate the damage evolution law of the connection components and the influence of component yielding on the stress of the rebar in the middle and bottom of the pier. The results show that the steel truss connection system yields in a row and consumes energy in a graded manner. The yielding order of the second and third rows of the steel truss connection system is always in the forefront. The second and third rows are the main energy-consuming rows, followed by the fourth, fifth, and sixth rows, and finally the seventh, eighth, and first rows, with the first and eighth rows being less likely to yield. The outer chord members in each row yield first, followed by the inner chord members, and the vertical and diagonal members are less likely to yield. The yielding of the pier columns occurs after the yielding of the chord members of the steel truss. The yielding of the outer chord members in the steel truss connection system has a certain inhibitory effect on the stress increase of the rebar in the pier columns and at the bottom of the pier, and the inhibitory effect on the bottom of the pier is better than that in the middle.
Experimental Study on Mechanical Properties of Permeated Crystalline Concrete
Authors: He Jingjing , Lu Haodan , Wang Haiting , Hu Wei , Wu Wenbo , Zhao Kunlong 
Published: November 2024

AbstractPerformance tests were conducted on concrete with different infiltration crystallization dosages. The influence of the dosage of permeable crystallization on the mechanical properties and durability of concrete is analyzed. The results show that infiltration crystallization has a significant improvement effect on the mechanical properties and durability of concrete. When the infiltration crystallization dosage is 1.2%, the increase in compressive strength, tensile strength, and compressive tensile elastic modulus of concrete reaches its maximum. When the infiltration crystallization dosage is 0.6%, the increase in the ultimate tensile strain value of concrete reaches its maximum. When the infiltration crystallization dosage increases within the range of 0–1.2%, the water seepage height and quality loss rate of concrete decrease to varying degrees, and there is a different degree of improvement compared to the dynamic modulus. The research results can provide reference for the mix design and engineering application of permeable crystalline concrete.