Journal of building engineering最新文献

{"title":"Effect of geopolymer recycled brick aggregates concrete cover on enhancing shear and bending properties of CFRP/GFRP/BFRP bars after elevated temperature exposure","authors":"Zike Wang ,&nbsp;Tengyu Cheng ,&nbsp;Jun Zhao ,&nbsp;Mingrui Du ,&nbsp;Eskinder Desta Shumuye ,&nbsp;Zhaohui Yang","doi":"10.1016/j.jobe.2025.112484","DOIUrl":"10.1016/j.jobe.2025.112484","url":null,"abstract":"<div><div>To address the issue of insufficient fire resistance in geopolymer concrete structures reinforced with FRP bars, recycled brick aggregates and fly ash cenospheres can be incorporated into geopolymer concrete to enhance its thermal insulation performance, thereby improving the fire resistance of FRP bars. This study investigates the degradation of FRP bars embedded in three types of concrete covers (GC, RC and FAC) after exposure to high temperatures. A total of 765 specimens were tested-255 each for transverse shear, short beam shear, and bending strength. The tests focused on the influence of factors such as heating temperature (20–800 °C), FRP bar type (CFRP, GFRP and BFRP), and concrete cover type (GC, RC and FAC). After heating, mass loss, residual transverse shear strength, apparent shear strength, bending strength, and bending elastic modulus retention were measured. The results showed that within the temperature range of 300–500 °C, three mechanical properties of bare FRP bars declined rapidly (decreased by more than 59 % compared to their initial values at 500 °C) due to decomposition of the resin, a phenomenon confirmed by surface morphology and failure mode observation. Notably, at 400 °C, the retentions for bare FRP bars are 40.78 %–86.01 % for transverse shear strength, 22.78 %–41.66 % for apparent shear strength and 2.08 %–14.28 % for bending strength, respectively. However, when FRP bars are embedded in GC, RC, and FAC, their residual mechanical performance increases sequentially. At 550°C, the bending strength retentions of CFRP bars embedded in GC, RC, and FAC are 3.32 %, 12.13 %, and 96.05 %, respectively. This demonstrates that the thermal insulation performance of GC, RC, and FAC increases sequentially. Finally, a verified strength prediction model was applied to evaluate the residual strength and fire resistance of FRP bars under different working conditions.</div></div>","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"105 ","pages":"Article 112484"},"PeriodicalIF":6.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Artificial intelligence-driven energy optimization in smart homes using interval-valued Fermatean fuzzy Aczel-Alsina aggregation operators","authors":"Tapan Senapati ,&nbsp;Guiyun Chen ,&nbsp;Witold Pedrycz","doi":"10.1016/j.jobe.2025.112418","DOIUrl":"10.1016/j.jobe.2025.112418","url":null,"abstract":"<div><div>This research explores integrating artificial intelligence (AI) in energy optimization for smart homes and buildings, specifically focusing on using Aczel-Alsina aggregation operators within an interval-valued Fermatean fuzzy (IVFF) decision-making framework. The primary goal of this study is to develop a robust method for managing uncertainty and imprecision in energy optimization tasks. Using IVFF Aczel-Alsina operators, the proposed approach effectively aggregates decision information, making it highly adaptable to dynamic and uncertain environments. Through a series of comparative analyses, the study demonstrates that this method outperforms traditional techniques for handling complex, ambiguous data, resulting in more efficient energy consumption management and improved occupant comfort. The findings also highlight the advantages of AI-driven decision-making systems in smart buildings, offering a path to enhanced sustainability and environmental responsibility. The key contribution of this research lies in the novel application of IVFF Aczel-Alsina operators for energy optimization, which presents a more flexible and reliable solution compared to existing methods. This approach is poised to advance smart home technologies, ensuring optimal energy use while addressing uncertainties in real-time applications. Future research could focus on expanding the scope of real-time integration and exploring additional parameters for further refinement of the methodology.</div></div>","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"105 ","pages":"Article 112418"},"PeriodicalIF":6.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143724761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimating the time constant using smart thermostat data acquisition and manipulation: A whole building experimental study","authors":"Danlin Hou ,&nbsp;Lukas Allan ,&nbsp;Hadia Awad ,&nbsp;Farid Bahiraei ,&nbsp;Ralph Evins","doi":"10.1016/j.jobe.2025.112485","DOIUrl":"10.1016/j.jobe.2025.112485","url":null,"abstract":"<div><div>The Time Constant RC is a key thermal characteristic of a building, combining the thermal resistance of the envelope (R) and the thermal mass (C). It serves as a useful indicator for ranking and prioritizing building retrofits by assessing the thermal performance of the building envelope through temperature measurements. However, accurately determining RC, especially on a large scale, poses significant challenges. This study employs Newton's Law of Cooling to estimate RC values from temperature data, using a full-scale facility designed to mimic a two-story residential townhouse in a cold climate region.</div><div>Although all extracted decay curves can meet common assumptions and requirements of Newton's Law of Cooling, the estimated RC values can vary substantially from 27.1 to 146.2 h. We investigated the factors influencing these variations, particularly focusing on data manipulation during the analysis of temperature drops that form distinct ‘decay curves.’ The findings emphasize the significance of the heating setpoint prior to the decay phase, as it plays a crucial role in RC estimation. Furthermore, the location of the trimmed decay curve within the entire decay period can lead to vastly different estimates, highlighting the importance of carefully selecting start and end points. The number of measurements used in the curve fitting is also critical, affecting the selection of these points. Additionally, the duration of the heating setpoint influences estimates primarily at the beginning of the thermal decay period. The proposed framework can be used as a standard method for fast, affordable, and scalable remote building energy auditing to rank order buildings and prioritize retrofit decisions.</div></div>","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"105 ","pages":"Article 112485"},"PeriodicalIF":6.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143744989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Innovative valorization of basic oxygen furnace slag in gypsum-based sustainable building blocks","authors":"Fengyi Zhang ,&nbsp;Chee Lok Yong ,&nbsp;Tee How Tan ,&nbsp;Chiu Chuen Onn ,&nbsp;Saznizam Sazmee Sinoh ,&nbsp;Chung-Chan Hung ,&nbsp;Kim Hung Mo","doi":"10.1016/j.jobe.2025.112489","DOIUrl":"10.1016/j.jobe.2025.112489","url":null,"abstract":"<div><div>Incorporating supplementary cementitious materials (SCMs) like ground granulated blast furnace slag (GGBS) into gypsum-based blocks enhances their compressive strength. However, over-reliance on GGBS is a concern due to its extensive use in the construction industry. To address this, basic oxygen furnace slag (BOFS) was introduced as a substitute for GGBS in producing gypsum-based blocks. Three mixture proportions of gypsum-based blocks were prepared with varying hemihydrate building gypsum contents and combined with 5 % ordinary Portland cement as an alkaline activator. The remaining SCM content, initially GGBS, was progressively replaced with BOFS. The results indicated that the low reactivity of BOFS, lower Al³⁺ content (5.50 %), and the presence of C₁₂A₇ led to decreased early compressive strength with increasing BOFS replacement. Nevertheless, the compressive strength development improved due to the formation of secondary hydration products. Microscopic analysis revealed that increased BOFS content enhanced the alkalinity and water content of the reaction system, thus promoting hydration reactions. In addition, the increase in BOFS content changed the morphology of C-S-H from an amorphous form to a fibrous-like structure with superior mechanical properties. In summary, gypsum-based blocks with 20 % BOFS used solely as the SCM attained a satisfactory 28-day compressive strength, which was 24 % higher than the counterpart specimens using GGBS as the SCM. These findings demonstrate the potential of BOFS as a novel SCM in gypsum-based materials.</div></div>","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"105 ","pages":"Article 112489"},"PeriodicalIF":6.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143724760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Progressive collapse risk assessment of unbonded prestressed slab-column structures under dynamic failure of bottom columns","authors":"Tao Qu ,&nbsp;Bin Zeng ,&nbsp;Chang Wu ,&nbsp;Linjie Huang ,&nbsp;Jing Wu ,&nbsp;Tianrui Geng","doi":"10.1016/j.jobe.2025.112499","DOIUrl":"10.1016/j.jobe.2025.112499","url":null,"abstract":"<div><div>Unbonded prestressed slab-column (UBPS-C) structures are prevalent in civil engineering due to their advantages, including simplified construction, reduced deformation, flexible arrangement, and cost savings. However, the absence of beams in UBPS-C structures may result in weakened resistance to progressive collapse, particularly when considering the potential negative effects of material, geometric, and loading uncertainties. Consequently, it is essential to assess the risk of progressive collapse of UBPS-C structures. In this paper, stochastic models of multi-story UBPS-C structures were developed through Latin hypercubic sampling (LHS), and incremental dynamic analysis (IDA) was performed. The vulnerability of the UBPS-C structure was analyzed based on the cumulative density function and performance level, with consideration of the bottom middle column, side column, and corner column failures. Within the range of significant damage, the exceeding probability under side and corner column failure exhibited minimal discrepancy. The lowest hazard was observed for the middle column failure scenario. Subsequently, the high-order moment method was employed to assess the reliability of the UBPS-C structure under these failure scenarios. The findings reveal that the structure exhibits the lowest reliability in the event of a corner column failure, while the risk posed by a side column failure should not be overlooked. Furthermore, uncertainty exacerbates the discrepancy in the residual structural resistance under different failure scenarios.</div></div>","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"105 ","pages":"Article 112499"},"PeriodicalIF":6.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143706427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prediction of interlaminar shear strength retention of FRP bars in marine concrete environments using XGBoost model","authors":"Xuan Zhao ,&nbsp;Pei-Fu Zhang ,&nbsp;Daxu Zhang ,&nbsp;Qi Zhao ,&nbsp;Yiliyaer Tuerxunmaimaiti","doi":"10.1016/j.jobe.2025.112466","DOIUrl":"10.1016/j.jobe.2025.112466","url":null,"abstract":"<div><div>The degradation of interlaminar shear strength (ILSS) of fiber-reinforced polymer (FRP) bars exhibits highly nonlinear characteristics when exposed to marine concrete environments. To address this phenomenon, a novel machine learning approach utilizing XGBoost algorithm was developed to predict ILSS retention (ILSSR). A comprehensive dataset was compiled from experimental results and existing literature. The constructed XGBoost model successfully captured the nonlinear degradation of ILSS and demonstrated excellent performance in terms of accuracy and generalization, achieving a testing R² value of 0.93 and a mean absolute error (MAE) of 3.78. The model represents a reliable and efficient tool for forecasting ILSSR of FRP bars in marine concrete environments. The coupling effects of FRP bar properties, exposure conditions and test parameters on ILSS degradation was further investigated through SHapley Additive exPlanations (SHAP), which offered a data-driven perspective that corroborated previous experimental findings. Utilizing the developed model, environmental reduction factors for ILSS under seawater sea-sand concrete (SWSSC) environment were quantified, taking into account the influence of fiber and matrix composition. The analysis revealed distinct environmental reduction factors: 0.71 for epoxy-based GFRP, 0.62 for epoxy-based BFRP, and 0.87 for vinyl-based GFRP bars. These findings underscore the substantial impact of matrix and fiber types on ILSSR, with the matrix type exerting a more dominant influence. The XGBoost-based predictive model developed in this study offers an effective and efficient method for assessing the long-term durability of FRP bars in marine concrete environments.</div></div>","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"105 ","pages":"Article 112466"},"PeriodicalIF":6.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143724758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling the thermal conductivity of the ground granulated blast furnace slag-based foam geopolymer based on its multi-scale pore structure","authors":"Suxi Wang ,&nbsp;Zhihao Zhang ,&nbsp;Jiaxi Mao ,&nbsp;Jialong Lin ,&nbsp;Fangduo Xiao ,&nbsp;Shikun Chen ,&nbsp;Yi Liu ,&nbsp;Hao Qian ,&nbsp;Dongming Yan","doi":"10.1016/j.jobe.2025.112487","DOIUrl":"10.1016/j.jobe.2025.112487","url":null,"abstract":"<div><div>The pore structure plays a crucial role in the thermal conductivity of porous materials. Foam geopolymers, with their inherently low thermal conductivity, show strong potential for building insulation. However, a quantitative model correlating their multi-scale pore structure with thermal conductivity is still lacking. This study prepared six types of ground granulated blast furnace slag-based foam geopolymers to investigate this relationship. The results confirm their effectiveness as thermal insulators, achieving a minimum thermal conductivity of 0.094 W/m·K. A detailed analysis of their multi-scale pore structure was conducted, treating micropores and macropores separately to capture their distinct effects. Based on experimental data and theoretical derivation, a thermal conductivity model was developed, introducing macropore shape as an innovative variable. The model demonstrated high accuracy in predicting thermal conductivity.</div></div>","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"105 ","pages":"Article 112487"},"PeriodicalIF":6.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143724759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 bar diameter and cover thickness on bond behavior of steel bar in high-strength SHCC under pull-out condition: Experimental study and efficient finite element modeling","authors":"Haroon Younas ,&nbsp;Jing Yu ,&nbsp;Christopher K.Y. Leung","doi":"10.1016/j.jobe.2025.112471","DOIUrl":"10.1016/j.jobe.2025.112471","url":null,"abstract":"<div><div>Engineered/Strain-Hardening Cementitious Composites (ECC/SHCC) are highly attractive for tensile/shear-critical regions in reinforced concrete structures due to their high tensile ductility and excellent crack control capacity. To ensure effective stress transfer, a sufficient bond between steel bars and SHCC is crucial, particularly for high-strength SHCC. This study experimentally and numerically investigates the bond behavior between deformed steel reinforcing bars and high-strength SHCC through a direct pull-out approach. Steel bars with different diameters (D = 20/25/32 mm) and cover thicknesses (1D, 1.5D and 2D) were examined, with a fixed bond length of 4D. The block materials included conventional concrete and high-strength SHCC with compressive strength of 112 MPa, tensile strength of 8.6 MPa and tensile strain capacity &gt;5 %. The findings demonstrated that SHCC can prevent the propagation of cracks, thereby maintaining the integrity of the bond. The bar diameter itself does not significantly affect the bond strength, while increasing the cover thickness from 1D to 2D effectively increases the peak loads and bond strength. A relatively simple but efficient finite element model was established, and the simulation showed good agreement with test results. These findings improve the understanding of bond characteristics of deformed steel bars with high-strength SHCC and facilitate the design of reinforced SHCC members.</div></div>","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"105 ","pages":"Article 112471"},"PeriodicalIF":6.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143715827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Harnessing biochar for green construction: A review of its applications in cement and concrete","authors":"Valluru Usha Rani ,&nbsp;P. Rathish Kumar ,&nbsp;R. Ramesh Nayaka","doi":"10.1016/j.jobe.2025.112462","DOIUrl":"10.1016/j.jobe.2025.112462","url":null,"abstract":"<div><div>The growing demand for concrete, driven by population and infrastructure growth, contributes significantly to environmental degradation, as each ton of cement produced releases about one ton of carbon dioxide. Sustainable solutions are crucial, and biochar, derived from carbon-rich biomass through pyrolysis, offers a promising approach. Its carbon sequestration potential helps reduce emissions while improving concrete's mechanical properties and durability. This review explores the use of Agro and Non-Agro biochar in cement-concrete composites, focusing on their effects on physical, mechanical, and durability properties, as well as CO₂ emissions. It also highlights optimal biochar percentages for sustainable concrete practices. The addition of biochar to mortar and concrete significantly influences hydration and rheological properties, enhancing strength development and resistance to plastic shrinkage cracking. Biochar improves mechanical strengths at lower dosages, increasing the overall density and cohesion of the mixture, which leads to enhanced compressive and flexural strength. However, excessive biochar amounts may negatively impact the mechanical properties of concrete. It is evident from the previous studies that the optimal biochar dosage as a binder replacement ranges from 2 % to 5 % for both Agro and Non-Agro biochar, while for fine aggregates, the recommended replacement is 10 %–15 %. Additionally, incorporating 2–3 % biochar in conventional cement or cement with supplementary cementitious materials reduce the CO₂ emissions by 15–30 % compared to samples without biochar. This paper also highlights, that the minimum biochar content for conventional mixes is 0.5 %–1 % by weight of the binder, true for both Agro-based and Nano Agro-based biochar. The maximum biochar content is identified as 10 % by weight of the binder. Thus, addition of biochar in cement products led to a sustainable solution with enhanced performance at optimum dosages.</div></div>","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"105 ","pages":"Article 112462"},"PeriodicalIF":6.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143715828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vertical coherence function model of along-wind fluctuating aerodynamic force on rectangular high-rise buildings with different side ratios","authors":"Kanghui Han ,&nbsp;Guohui Shen ,&nbsp;Yonghan Jiang ,&nbsp;Lin Zheng ,&nbsp;Yong Chen","doi":"10.1016/j.jobe.2025.112494","DOIUrl":"10.1016/j.jobe.2025.112494","url":null,"abstract":"<div><div>In order to investigate the vertical coherence of the along-wind aerodynamic fluctuating force on rectangular high-rise buildings with different side ratios, synchronized pressure tests were conducted for rectangular models with thirteen side ratios (1/8-8) under two turbulent boundary layer flows in the wind tunnel. The spatial correlation of along-wind fluctuating wind loads was investigated. Results showed that the correlation coefficients of wind pressure on windward and leeward walls were lower than the drag coefficients. The coherence function of the along-wind aerodynamic fluctuating force on rectangular high-rise buildings exhibits an exponential decrease as the frequency increases, and it has a value less than 1 when the frequency is equal to 0. As the vertical distance increases, the coherence function gradually decreases. In addition, an increase in the ratio of building breadth to the turbulence integral length scale leads to a decrease in the decay parameter of the coherence function. The existing coherence function models have difficulty accurately capturing the variation of the coherence function with side ratio, especially for the side ratios less than 1/4 and more than 4, and these models differ significantly from the coherence function calculated by experimental results when the vertical distance is large. Therefore, to fulfill the requirements in engineering, a new generalized coherence function model was developed, incorporating the influence of side ratio, wind velocity, turbulence integral length scale, and vertical distance, and it agrees well with the experimental results across side ratios from 1/8 to 8. The wind-induced displacement and acceleration calculated by the proposed coherence function model agree better with those calculated by experimental values than the empirical models proposed by Davenport and GB 50009-2012.</div></div>","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"105 ","pages":"Article 112494"},"PeriodicalIF":6.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143715903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}