Construction and Building Materials最新文献

{"title":"Green preparation and performance research of n-octadecane@silica phase change microcapsules for building energy conservation","authors":"YunYi Tan,&nbsp;PeiXuan Li,&nbsp;Yu Yao,&nbsp;HaiFeng Li,&nbsp;Jian Zhong,&nbsp;Jingwen Wu,&nbsp;Yan Zhang,&nbsp;Jifen Wang","doi":"10.1016/j.conbuildmat.2025.143847","DOIUrl":"10.1016/j.conbuildmat.2025.143847","url":null,"abstract":"<div><div>The synthesis of microencapsulated phase change materials (MPCMs) was accomplished via a green, low-temperature (45 ℃), low-shear (800–1000 rpm) interfacial sol–gel process, a method that circumvents the utilisation of strong acids and bases. These MPCMs are constituted of silica shells and <em>n-</em>octadecane cores. Utilising an optimised SDS/CTAB emulsifier system, uniform spherical microcapsules with a main diameter of 0.81 μm were obtained. The optimised MPCM2 exhibited high latent heat (ΔH_m 124.9 ± 0.8 J/g; ΔH_c 126.1 ± 1.2 J/g) with an encapsulation efficiency of 56.9 ± 0.4 %, whilst thermogravimetry showed the decomposition onset increased to 185.2 °C relative to neat <em>n-</em>octadecane (119.4 °C). Following 500 thermal cycles, enthalpy attenuation was recorded at only 1.2 %, thereby confirming excellent durability. When incorporated into cement boards at a 20 wt% loading, MPCM2 demonstrated a 41.14 % reduction in thermal conductivity and a 21.9 % decrease in temperature fluctuation when subjected to repetitive cycling between 5 and 120 °C (γ=0.781). No leakage or discernible chemical interaction with the matrix was observed, as substantiated by FT‑IR, XRD and SEM‑EDX analysis. The cementitious microstructure remained intact, with well-dispersed microcapsules, and compressive strength was maintained when 20 wt% MPCM2 was combined with 20 wt% quartz sand. The findings of this study demonstrate an environmentally benign approach to the fabrication of high-performance MPCMs, thereby validating their efficacy in thermal regulation within cement-based building components.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"497 ","pages":"Article 143847"},"PeriodicalIF":8.0,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Shear behavior and damage identification of π-shaped demountable connector for composite beam equipped with acoustic emission sensors","authors":"Jun He ,&nbsp;Yuanwang Li ,&nbsp;Hongli Li ,&nbsp;Yafei Ma ,&nbsp;Sidong Feng ,&nbsp;Zitong Wang","doi":"10.1016/j.conbuildmat.2025.143811","DOIUrl":"10.1016/j.conbuildmat.2025.143811","url":null,"abstract":"<div><div>To advance rapid assembly methodologies in steel-concrete composite bridges, this study proposes a novel demountable π-shaped shear connector and systematically investigates its structural performance. Two configurations, longitudinal (L-Conn) and transverse (T-Conn) π-shaped connectors, were designed and evaluated via standardized push-out tests to explore failure mechanisms under shear loading. Experimental results demonstrate that concrete-filled configurations achieve comparable ultimate shear capacities (T-Conn: 844 kN; L-Conn: 915 kN), yet exhibit a notable divergence in ultimate displacements (T-Conn: 5.19 mm vs. L-Conn: 8.78 mm). In contrast, unfilled connectors fail prematurely due to internal deformation localization and stress redistribution. Stiffness evolution reveals a nonlinear trend, with transverse configurations exhibiting higher initial stiffness than longitudinal counterparts. A high-precision finite element model, validated against experimental data, replicates critical failure modes and load-slip behavior within 5 % error. Complementary acoustic emission (AE) monitoring equipment captures fracture progression through energy, ring count, amplitude, rise time, and duration parameters. During elastoplastic stage, a surge of high-energy AE signals (energy &gt;10,000 aJ) correlates with bolt yielding and interfacial concrete damage. Statistical analysis identifies weak amplitude-parameter correlations but strong energy-based interdependencies, prompting the development of a cumulative damage model integrating energy-amplitude thresholds for real-time degradation assessment. Theoretical validation confirms alignment with Eurocode 4 (EC4) shear capacity predictions (error &lt;10 %). These findings establish a framework for non-destructive evaluation and structural health monitoring of demountable connectors, directly supporting the design and life-cycle management of modular composite bridges.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"497 ","pages":"Article 143811"},"PeriodicalIF":8.0,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental testing on the creep behavior of laminated veneer lumber (LVL) under various compression directions","authors":"Xijun Wang ,&nbsp;Minjuan He ,&nbsp;Pengfei Dai","doi":"10.1016/j.conbuildmat.2025.143877","DOIUrl":"10.1016/j.conbuildmat.2025.143877","url":null,"abstract":"<div><div>As an engineered wood product (EWP), laminated veneer lumber (LVL) exhibits two inherent wood characteristics: anisotropic mechanical properties and time-dependent creep behavior. Understanding the creep behavior of LVL is crucial for its applications. This paper presents an experimental investigation into the creep behavior of LVL under three compression directions: compression parallel to grain, edgewise compression perpendicular to grain, and flatwise compression perpendicular to grain. Short-term compression tests were first conducted on LVL along the three directions, providing basic data to determine the stress magnitude for long-term compression tests. The long-term tests were performed for 220 days in an uncontrolled indoor environment, considering the three compression directions and different stress levels. The long-term behavior of the LVL specimens was assessed across time-dependent moisture contents, strain, and creep. Creep models were then calibrated against the experimental data, further characterizing the compressive creep behavior of LVL. The experimental results show that the moisture content and environmental strain exhibited a strong but slightly lagged correlation with relative humidity. The maximum creep coefficients at 77.9 % average humidity were 1.87–3.25 times as large as those at 61.7 % humidity. Creep effect in LVL under parallel-to-grain compression was significantly lower than that subjected to compression perpendicular to grain. The flatwise-compression-perpendicular-to-grain LVL exhibited larger creep coefficients compared to that in edgewise compression configuration. The low-stress LVL had lower creep coefficients compared to that in high-stress scenarios.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"497 ","pages":"Article 143877"},"PeriodicalIF":8.0,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantifying the self-healing phenomenon in cement-based materials: Insights from ultrasound tests and optical microscopy","authors":"Deividi Maurente-Silva ,&nbsp;João Vitor Bitencourt Borowski ,&nbsp;Angela Borges Masuero ,&nbsp;Denise Carpena Coitinho Dal Molin","doi":"10.1016/j.conbuildmat.2025.143899","DOIUrl":"10.1016/j.conbuildmat.2025.143899","url":null,"abstract":"<div><div>The self-healing phenomenon is gaining significant attention in the scientific community, both for its potential to reduce high maintenance costs over a structure's lifespan and to gradually decrease the resources required for concrete production. The performance evaluation of various agents influencing the self-healing behavior of cementitious matrices can be conducted through direct or indirect methods. This study assessed three-day cracked concretes containing silica fume, crystalline admixture, or superabsorbent polymer using optical microscopy and ultrasound tests. Image analysis was performed at magnifications of 80x and 160x, processed and quantified by three distinct methodologies. In determining Ultrasonic Pulse Velocity (UPV), the variables included reading position, transducer frequency, and moisture content. Key parameters identified in the image analysis were lighting conditions, sample saturation, magnification, and the automation of cracked area quantification. The 54 kHz exponential transducers statistically distinguished themselves from the other frequencies analyzed, as did the influence of moisture on UPV.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"497 ","pages":"Article 143899"},"PeriodicalIF":8.0,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of 3D porous graphene on the mechanical properties and microstructure of ultra-high ductility concrete","authors":"Meiyan Bai ,&nbsp;Long Song ,&nbsp;Feng Xie ,&nbsp;Zhenyuan Lv ,&nbsp;Haoran Liu","doi":"10.1016/j.conbuildmat.2025.143871","DOIUrl":"10.1016/j.conbuildmat.2025.143871","url":null,"abstract":"<div><div>To enhance the mechanical and microstructural properties of ultra-high ductility concrete (UHDC), this study introduced three-dimensional porous graphene (3DG) as a nano-reinforcement and systematically investigated its effects on the workability, mechanical properties, pore structure, and hydration behavior of UHDC. Results showed that 0.03 wt% 3DG yielded optimal improvements. Compressive strength increased by 18.8 % and tensile strain capacity rose by 71.75 % compared to the control. At this dosage, after measuring the actual elongation of the tensile specimens and counting the number of cracks, it was found that the average crack width decreased from 267 micrometers to 185 micrometers, while the number of cracks within an 80-millimeter gauge length increased from 21 to 39. MIP analysis revealed that 3DG refined the pore structure by reducing harmful pores (&gt;100 μm) and increasing medium-sized pores (60–100 μm), despite a slight rise in overall porosity. XRD and TGA results indicated that 3DG promoted the formation of dense C–S–H gels and enhanced hydration, resulting in higher crystallinity and thermal stability. SEM images confirmed the formation of a dense fiber–matrix interface and complex C–S–H networks surrounding 3DG particles. These improvements stem from 3DG's bridging, nucleation, and internal curing functions, offering a multiscale reinforcement effect that significantly boosts toughness and crack resistance.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"497 ","pages":"Article 143871"},"PeriodicalIF":8.0,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145218989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bond strength of steel rebar and concrete after different cooling methods: Experimental study and theoretical modeling","authors":"Caiwei Liu ,&nbsp;Kexin Zhao ,&nbsp;Lizheng Liu ,&nbsp;Liangtai Yan ,&nbsp;Jijun Miao","doi":"10.1016/j.conbuildmat.2025.143851","DOIUrl":"10.1016/j.conbuildmat.2025.143851","url":null,"abstract":"<div><div>Water spray cooling is a commonly used method to cool structures after fire exposure. However, existing studies have largely overlooked the impact of factors such as cooling methods, concrete cover thickness, and stirrup ratio on the bond failure mode between steel rebar and concrete, and have rarely examined the bond failure mechanism in detail. To address these issues, this study conducted pull-out tests on 126 specimens, considering the influence of various parameters. The failure modes and bond slip responses under different conditions were recorded and analyzed, leading to the establishment of preliminary criteria for identifying bond failure modes. Digital Image Correlation (DIC) was employed to monitor the strain field during and after cooling, providing insights into the dynamic evolution of cracks in the concrete. An improved bond strength prediction model was developed to account for different failure modes, incorporating the interaction between longitudinal-radial and radial-circumferential stress planes. The model enables comprehensive prediction, from test input parameters to failure mode identification and bond strength evaluation. This method provides a more accurate mechanical basis for assessing bond deterioration after fire exposure. It also offers practical guidance for repairing fire-damaged concrete structures.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"497 ","pages":"Article 143851"},"PeriodicalIF":8.0,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145218990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding rutting susceptibility of polymer modified asphalt mixes for different traffic loading conditions using binder characterization and simple performance tests","authors":"Gavadakatla Vamsikrishna,&nbsp;Dharamveer Singh","doi":"10.1016/j.conbuildmat.2025.143887","DOIUrl":"10.1016/j.conbuildmat.2025.143887","url":null,"abstract":"<div><div>The present study investigated the rutting performance of plant produced polymer modified asphalt mixes using binder characterization and simple performance tests. The asphalt binder rutting properties were estimated in terms of non-recoverable creep compliance (J_nr), Superpave rutting factor (|G*|/Sinδ), failure temperature, and softening point. The rutting resistance of asphalt mixes was evaluated using high temperature indirect tensile strength (HT-IDT) test, ideal rutting test (IDEAL-RT), and Marshall rutting test (Marshall-RT). Six different plant-produced SBS (elastomeric) modified asphalt mixtures and binders having a performance grade (PG) of 76-XX or higher were evaluated. The findings showed strong correlations between the asphalt mixtures and asphalt binder rutting parameters. Moreover, preliminary threshold acceptance criteria were established for the simple performance tests at 50°C corresponding to binder J_{[email protected]} for different traffic loading categories. These threshold values can be helpful in production of rut-resistant asphalt mixtures during the mix design and plant-production stages for quality control (QC) and quality assurance (QA) purposes. Moreover, the study established preliminary threshold criteria for asphalt binder parameters which aids in selecting high-quality binders to enhance the performance of asphalt mixtures. Overall, this study provides a practical framework to highway agencies and practitioners to accurately evaluate the rutting resistance of polymer modified asphalt mixtures, highlighting the critical role of binder properties in producing high-performance asphalt mixtures.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"497 ","pages":"Article 143887"},"PeriodicalIF":8.0,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145204238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deformation of underlying shield tunnel caused by adjacent excavation considering the consolidation effect","authors":"LinHai Lv ,&nbsp;Shaokang Zhu ,&nbsp;Cheng Dong ,&nbsp;Zhonghui Huang ,&nbsp;BingHua Wang ,&nbsp;ShiZheng Qiu ,&nbsp;MingJie Jiang ,&nbsp;Liang Xiao ,&nbsp;Guoxiong Mei","doi":"10.1016/j.conbuildmat.2025.143841","DOIUrl":"10.1016/j.conbuildmat.2025.143841","url":null,"abstract":"<div><div>Excavation above existing tunnels induces vertical deformation due to unloading effects, with the underlying tunnel deformation exhibiting time-dependent behavior caused by soil consolidation. However, prevailing theoretical frameworks often neglect the consolidation process and the influence of the complete excavation sequence, resulting in an inability to predict time-evolving deformation. This study establishes a consolidation model tailored for foundation pit excavation, deriving a theoretical solution for excess pore water pressure. Vertical soil deformation induced by excavation is determined using the effective stress principle coupled with generalized Hooke's law. A consolidation model for internally loaded foundations is then formulated to obtain a flexibility matrix incorporating consolidation effects. By simplifying the tunnel as an Euler-Bernoulli beam and applying soil-tunnel displacement coupling conditions, a time-dependent solution for vertical deformation is derived and validated against physical model tests. Meanwhile, the results of data comparison further indicate that the time-dependent characteristics of the tunnel's vertical deformation are closely related to the dissipation of excess pore water pressure (i.e., the soil's consolidation characteristics). Parametric analysis shows that: Lowering the soil permeability coefficient reduces the tunnel’s deformation rate but also extends the time required for the deformation to stabilize, resulting in a smaller vertical displacement at the completion of excavation. An increase in the resilient modulus not only enhances the soil's ability to resist deformation but also weakens the soil's consolidation effect, thereby inhibiting the development of vertical displacement of the tunnel. The tunnel stiffness only affects the deformation magnitude, but not the time required to reach stability. Introducing an intermittent excavation schedule tends to increase the deformation of the tunnel by the end of excavation while attenuating the subsequent time-dependent deformation. The theory in this paper is of guiding significance for engineering practice.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"497 ","pages":"Article 143841"},"PeriodicalIF":8.0,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145218987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on the characteristics and performance of nano-silica/unsaturated polyester resin composite modified asphalt waterproof adhesive layer","authors":"Ruixiang Wang ,&nbsp;Hongliang Zhang ,&nbsp;Longfei Yang ,&nbsp;Kongfa Zhu","doi":"10.1016/j.conbuildmat.2025.143868","DOIUrl":"10.1016/j.conbuildmat.2025.143868","url":null,"abstract":"<div><div>The waterproof adhesive layer (WAL) is a critical structure that effects the service life of bridge deck pavement. However, ordinary asphalt-based WAL materials commonly suffer from significant degradation of bond strength at high temperatures, leading to functional failure. To address this issue, this paper developed a novel WAL material by compositely modifying asphalt with nano-silica (NS) and unsaturated polyester resin (UPR). Subsequently, a comprehensive analysis of the composite modification effects of NS/UPR and the performance of composite modified asphalt as a WAL material was conducted through a series of experimental tests. The results indicated that the optimal mass ratio for the NS/UPR composite modified asphalt was coupling agent: NS: UPR: initiator: asphalt: compatibilizer = 3:3:100:4:282:4. The incorporation of NS promoted the uniform dispersion of UPR within the asphalt matrix, enhancing the toughness and high-temperature stability of the modified asphalt while mitigating the adverse impact of UPR on low-temperature cracking resistance. In terms of adhesion performance, the pull-off strength of the NS/UPR composite modified asphalt was 1.59 and 1.48 times that of the matrix asphalt and SBS modified asphalt, respectively. Durability tests further confirmed its superior weather resistance and ability to endure a greater number of load cycles. Overall, the novel WAL material developed in this paper demonstrated excellent adhesion performance at elevated temperatures together with favorable comprehensive properties, which expanding the potential applications of UPR in road engineering.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"497 ","pages":"Article 143868"},"PeriodicalIF":8.0,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding the transparent to cloudy transition of silicate interlayers in fire-resistant glass","authors":"Kai Ye ,&nbsp;Pio J.S. Buenconsejo ,&nbsp;Kai Xue ,&nbsp;Aravind Dasari","doi":"10.1016/j.conbuildmat.2025.143832","DOIUrl":"10.1016/j.conbuildmat.2025.143832","url":null,"abstract":"<div><div>Alkali silicate systems have been widely used to improve the fire resistance of glass, wood, steel and polymers. However, a key durability challenge with these materials as interlayers in fire-resistant glass is their transparent to cloudy transition. Though several empirical measures were reported for mitigation, the lack of clarity of the underlying mechanism has limited their effectiveness. In this work, the structural transformations of alkali silicate systems of varying molar ratios at different length and time scales are investigated with the aid of multiple characterization techniques, including ²⁹Si magic angle spinning nuclear magnetic resonance (MAS NMR), small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). It is found that the distribution state of particles and the interparticle distance significantly contribute to the transition. Specifically, the formation of interparticle networks and aggregates can lead to light scattering, resulting in irreversible loss of transparency. Additionally, heat treatment can induce the coalescence of particles, resulting in a matrix-dominated structure devoid of scattering features. This transformation can lead to an opaque to transparent reversal. The fundamental insights gained from this research are crucial for developing durable silicate systems suitable for fire-resistant glass and other potential applications. The novel research protocol presented here can be further applied to future research on similar material systems and their associated behaviors.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"497 ","pages":"Article 143832"},"PeriodicalIF":8.0,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145204361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}