Journal of building engineering最新文献

{"title":"Integrated utilization of recycled waste concrete powder and waste glass power for preparation of foam ceramics","authors":"Qing Tian, Mengyue Ruan, Zhiyong Zhao, Gelong Xu, Jiwei Cai, Tiejun Zhao, Qiang Fu","doi":"10.1016/j.jobe.2024.111352","DOIUrl":"https://doi.org/10.1016/j.jobe.2024.111352","url":null,"abstract":"Using multi-solid wastes to prepare foam ceramics, it can not only recycle a large amount of solid waste, but also obtain products with excellent performance. In this study, foam ceramics were prepared by sintering method using recycled waste concrete powder and waste glass power as main raw material. The effect of foaming agent content on the physical properties and pore structure of foam ceramics were investigated. The matching relationship between the amount of flux and foaming agent was also analyzed. The results revealed that when the flux was 5 g and the foaming agent was 10 g, the foam ceramics showed the best overall performance. The compressive strength, bulk density, water absorption and porosity were 6.43 MPa, 1.10 g/cm<ce:sup loc=\"post\">3</ce:sup>, 2.03 % and 54.35 %, respectively. At this time, the pore size distribution was optimal, and mesopore occupied the vast majority. The fractal dimension and pore shape factor reached the minimum of 1.344 and 1.076. If the foaming agent was too much, the amount of flux should be appropriately increased. When Na<ce:inf loc=\"post\">2</ce:inf>CO<ce:inf loc=\"post\">3</ce:inf> content were 12 g and 14 g, the borax were at least 7 g and 9 g, respectively. The matching of flux and foaming agent can significantly improve the foaming effect. The experimental results showed that it was feasible to prepare foam ceramics by using recycled waste concrete powder and waste glass power. The prepared foam ceramics can basically reach or even exceed the current mainstream level. In addition, this foam ceramics showed great environmental and economic prospects.","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"99 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670434","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":"Ventilation strategy for particulate matter control in subway stations","authors":"Jing Song, Yongzhi Zhang, Yan Huang, Ping Wang, Bingqiang Yang","doi":"10.1016/j.jobe.2024.111323","DOIUrl":"https://doi.org/10.1016/j.jobe.2024.111323","url":null,"abstract":"Particulate matter severely affects human health, and its migration is closely related to human walking and ventilation. It is essential to select an appropriate ventilation strategy to control the particulate matter caused by cluster passengers walking. In this study, cluster passengers walk in the narrow passage of a subway station. Large eddy simulation (LES) was used to study the influence of cluster passengers walking on the transmission of particulate matter under ventilation conditions involving upper exhaust and lower exhaust. The risk of passengers exposure was analyzed by comparing the exposure levels of particulate matter at different heights under the effect of human disturbance. The results show that the amount of particulate matter near the legs is greatest during human walking. Clustered passengers disturbance airflow induces particulate matter to rise to the breathing zone, which increases the risk of human exposure. Lower-side exhaust conditions are more conducive to the discharge and control of particulate matter. The disturbance of cluster passengers enhances the continuous transmission of particulate matter in the wake flow. This study is applicable to traffic hubs and other public places where passengers gather, the ventilation of the upper side exhaust has better control effect on particulate matter caused by passengers wake flow.","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"249 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670446","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":"Microstructure-informed deep learning model for accurate prediction of multiple concrete properties","authors":"Ye Li, Yiming Ma, Kang Hai Tan, Hanjie Qian, Tiejun Liu","doi":"10.1016/j.jobe.2024.111339","DOIUrl":"https://doi.org/10.1016/j.jobe.2024.111339","url":null,"abstract":"Predicting multiple properties of concrete using empirical models has become increasingly challenging due to the complexity of modern concrete formulations and the nonlinear behavior of their constituents. This study introduces a sequential model that integrates mix proportions with microstructural information of concrete. The model addresses the limitations of small datasets and the inherent variability in concrete's raw materials and production processes. A novel dataset comprising concrete mix proportions, 56,160 scanning electron microscope images, and their corresponding macroscopic properties was constructed for training and validation. We developed a sequential model integrating a Swin Transformer (Swin-T) with a Back Propagation Neural Network (BPNN), achieving superior accuracy in predicting compressive strength and permeability. Comprehensive evaluations using SHAP and GradCAM reveal the critical role of hydration products in these predictions, underscoring the enhanced interpretability and efficacy of our approach. This work advocates for the integration of microstructural insights to improve the reliability and precision of concrete assessments.","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"249 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670430","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":"The energy and exergy examination of a thermoelectric ventilation system powered by photovoltaic/thermoelectric for space cooling and heating in a residential building","authors":"Yejiong Xing, Suqi Wang","doi":"10.1016/j.jobe.2024.111305","DOIUrl":"https://doi.org/10.1016/j.jobe.2024.111305","url":null,"abstract":"In the present study, the thermoelectric ventilation (TEV) system, whose electricity is supplied by a system consisting of concentrating photovoltaic (CPV) panels cooled with thermoelectric generators (TEGs), is used to supply the heating and cooling loads of a building located in Huaian city (Jiangsu, China). Two new parameters named Energy Proficiency Indicator (&lt;mml:math altimg=\"si1.svg\"&gt;&lt;mml:mrow&gt;&lt;mml:msub&gt;&lt;mml:mrow&gt;&lt;mml:mi&gt;P&lt;/mml:mi&gt;&lt;mml:mi&gt;I&lt;/mml:mi&gt;&lt;/mml:mrow&gt;&lt;mml:mrow&gt;&lt;mml:mi&gt;e&lt;/mml:mi&gt;&lt;mml:mi&gt;n&lt;/mml:mi&gt;&lt;/mml:mrow&gt;&lt;/mml:msub&gt;&lt;/mml:mrow&gt;&lt;/mml:math&gt;) and Exergy Proficiency Indicator (&lt;mml:math altimg=\"si2.svg\"&gt;&lt;mml:mrow&gt;&lt;mml:msub&gt;&lt;mml:mrow&gt;&lt;mml:mi&gt;P&lt;/mml:mi&gt;&lt;mml:mi&gt;I&lt;/mml:mi&gt;&lt;/mml:mrow&gt;&lt;mml:mrow&gt;&lt;mml:mi&gt;e&lt;/mml:mi&gt;&lt;mml:mi&gt;x&lt;/mml:mi&gt;&lt;/mml:mrow&gt;&lt;/mml:msub&gt;&lt;/mml:mrow&gt;&lt;/mml:math&gt;) are defined to determine the contribution of the CPV/TEG-TEV system in supplying the heating and cooling loads of the building. The value of these parameters is calculated for a base case. Then, the effect of concentration ratio, mass flow rate of supply air, area of PV module, number of TEGs, and number of thermoelectric coolers on the annual average of these parameters (i.e., &lt;mml:math altimg=\"si3.svg\"&gt;&lt;mml:mrow&gt;&lt;mml:msub&gt;&lt;mml:mrow&gt;&lt;mml:mi&gt;P&lt;/mml:mi&gt;&lt;mml:mi&gt;I&lt;/mml:mi&gt;&lt;/mml:mrow&gt;&lt;mml:mrow&gt;&lt;mml:mi&gt;e&lt;/mml:mi&gt;&lt;mml:mi&gt;n&lt;/mml:mi&gt;&lt;mml:mo&gt;,&lt;/mml:mo&gt;&lt;mml:mi&gt;y&lt;/mml:mi&gt;&lt;mml:mi&gt;a&lt;/mml:mi&gt;&lt;/mml:mrow&gt;&lt;/mml:msub&gt;&lt;/mml:mrow&gt;&lt;/mml:math&gt; and &lt;mml:math altimg=\"si4.svg\"&gt;&lt;mml:mrow&gt;&lt;mml:msub&gt;&lt;mml:mrow&gt;&lt;mml:mi&gt;P&lt;/mml:mi&gt;&lt;mml:mi&gt;I&lt;/mml:mi&gt;&lt;/mml:mrow&gt;&lt;mml:mrow&gt;&lt;mml:mi&gt;e&lt;/mml:mi&gt;&lt;mml:mi&gt;x&lt;/mml:mi&gt;&lt;mml:mo&gt;,&lt;/mml:mo&gt;&lt;mml:mi&gt;y&lt;/mml:mi&gt;&lt;mml:mi&gt;a&lt;/mml:mi&gt;&lt;/mml:mrow&gt;&lt;/mml:msub&gt;&lt;/mml:mrow&gt;&lt;/mml:math&gt;) is investigated. The results indicated that the &lt;mml:math altimg=\"si1.svg\"&gt;&lt;mml:mrow&gt;&lt;mml:msub&gt;&lt;mml:mrow&gt;&lt;mml:mi&gt;P&lt;/mml:mi&gt;&lt;mml:mi&gt;I&lt;/mml:mi&gt;&lt;/mml:mrow&gt;&lt;mml:mrow&gt;&lt;mml:mi&gt;e&lt;/mml:mi&gt;&lt;mml:mi&gt;n&lt;/mml:mi&gt;&lt;/mml:mrow&gt;&lt;/mml:msub&gt;&lt;/mml:mrow&gt;&lt;/mml:math&gt; for September was obtained as the highest value (1.68) among the other months followed by February, March, and April. Moreover, April, May, and September exhibited the highest &lt;mml:math altimg=\"si2.svg\"&gt;&lt;mml:mrow&gt;&lt;mml:msub&gt;&lt;mml:mrow&gt;&lt;mml:mi&gt;P&lt;/mml:mi&gt;&lt;mml:mi&gt;I&lt;/mml:mi&gt;&lt;/mml:mrow&gt;&lt;mml:mrow&gt;&lt;mml:mi&gt;e&lt;/mml:mi&gt;&lt;mml:mi&gt;x&lt;/mml:mi&gt;&lt;/mml:mrow&gt;&lt;/mml:msub&gt;&lt;/mml:mrow&gt;&lt;/mml:math&gt;; 26.4, 21.71, and 21.38, respectively. Furthermore, it was revealed that both the &lt;mml:math altimg=\"si3.svg\"&gt;&lt;mml:mrow&gt;&lt;mml:msub&gt;&lt;mml:mrow&gt;&lt;mml:mi&gt;P&lt;/mml:mi&gt;&lt;mml:mi&gt;I&lt;/mml:mi&gt;&lt;/mml:mrow&gt;&lt;mml:mrow&gt;&lt;mml:mi&gt;e&lt;/mml:mi&gt;&lt;mml:mi&gt;n&lt;/mml:mi&gt;&lt;mml:mo&gt;,&lt;/mml:mo&gt;&lt;mml:mi&gt;y&lt;/mml:mi&gt;&lt;mml:mi&gt;a&lt;/mml:mi&gt;&lt;/mml:mrow&gt;&lt;/mml:msub&gt;&lt;/mml:mrow&gt;&lt;/mml:math&gt; and &lt;mml:math altimg=\"si4.svg\"&gt;&lt;mml:mrow&gt;&lt;mml:msub&gt;&lt;mml:mrow&gt;&lt;mml:mi&gt;P&lt;/mml:mi&gt;&lt;mml:mi&gt;I&lt;/mml:mi&gt;&lt;/mml:mrow&gt;&lt;mml:mrow&gt;&lt;mml:mi&gt;e&lt;/mml:mi&gt;&lt;mml:mi&gt;x&lt;/mml:mi&gt;&lt;mml:mo&gt;,&lt;/mml:mo&gt;&lt;mml:mi&gt;y&lt;/mml:mi&gt;&lt;mml:mi&gt;a&lt;/mml:mi&gt;&lt;/mml:mrow&gt;&lt;/mml:msub&gt;&lt;/mml:mrow&gt;&lt;/mml:math&gt; are improved by boosting the mass flow rate of supply air, area of PV module, number of TEGs, and number of thermoelectric co","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"22 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670437","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":"Optimization design of layout dimension for residential buildings weighing up daylighting, thermal comfort, and indoor air quality with a low-carbon decision-making","authors":"Sheng Yao, Min Li, Jingyu Yuan, Qiao Huo, Shiya Zhao, Ying Wu","doi":"10.1016/j.jobe.2024.111328","DOIUrl":"https://doi.org/10.1016/j.jobe.2024.111328","url":null,"abstract":"In response to the growing demand for living environment, enhancing the physical environment of residential buildings has become an imperative priority. This study proposes an optimization and low-carbon decision-making framework. Interestingly, a multi-objective optimization model was developed by integrating a backpropagation neural network with the NSGA-II algorithm, and a carbon emission model was incorporated into the decision-making process to obtain optimal design parameters. To substantiate the applicability of this methodology, it will be applied to a prototypical model of residential buildings, which consists of multiple physical environmental units. Five types of design variables were identified, including layout dimension, window-to-wall ratio, building orientation, building envelope, and openable window area ratio. And the correlation analysis was conducted on three optimization objectives of useful daylight illuminance, percentage of predicted dissatisfaction and indoor CO<ce:inf loc=\"post\">2</ce:inf> concentration. The results indicate that all design variables have been retained as key design variables, and the three objectives meet the necessity of multi-objective optimization. Moreover, the constructed neural network prediction model has high accuracy. Compared with the prototypical model, layout dimensions of the optimal solution exhibited the greatest changes in the width and depth of kitchen, with respective increases by 25.38 % and 21.46 %. The unit modules of the residential buildings with the worst performance have been effectively optimized, the useful daylight illuminance has increased by 2.23 %, the percentage of predicted dissatisfaction has decreased by 11.5 %, the indoor CO<ce:inf loc=\"post\">2</ce:inf> concentration has decreased by 48 %, and the operational carbon emissions per unit area has decreased by 14 %.","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"62 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670438","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":"Alkali activation of rock wool furnace slag: Effects of water glass modulus, Na2O content, and nano-TiO2","authors":"Jiaqi Zhu, Chang Chen, Xufu Wang, Shaowu Jiu, Yanxin Chen, Yan Liu","doi":"10.1016/j.jobe.2024.111338","DOIUrl":"https://doi.org/10.1016/j.jobe.2024.111338","url":null,"abstract":"Rock wool, as an external wall insulation material, is crucial in improving the energy efficiency of structures. However, a large amount of rock wool furnace slag (RWFS) generated during the production of rock wool panels manufacturing causes environmental problems. To address these issues, this study focuses on the use of waste RWFS as a precursor in alkali-activated cementitious materials. In addition, the effect of anatase nano-TiO<ce:inf loc=\"post\">2</ce:inf> (ANT) and rutile nano-TiO<ce:inf loc=\"post\">2</ce:inf> (RNT) as an additive to the alkali-activated rock wool furnace slag cementitious materials (AARWFSCMs) was evaluated and quantified. Scanning Electronic Microscope (SEM), Isothermal Conduction Calorimetry (ICC), Fourier-Transform Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD) analysis were used to identify the effects of modulus 1.0–1.8 water glass modulus (Ms; SiO<ce:inf loc=\"post\">2</ce:inf>/Na<ce:inf loc=\"post\">2</ce:inf>O), 3%–7% Na<ce:inf loc=\"post\">2</ce:inf>O content on AARWFSCMs. Experimental tests was conducted to quantify the properties such as the setting time, the fluidity, the compressive strength of AARWFSCMs after hardening. Results found that the optimal content of Ms, Na<ce:inf loc=\"post\">2</ce:inf>O content in preparing AARWFSCM were 1.4, 5 % for obtaining 28-d compressive strength of 96.36 MPa. The atomic percentage of Ca/Si of the hydration products in the AARWFSCMs fluctuated within 0.94–1.50. The hydration products were a mixture of C–S–H and C–A–S–H. Moreover, the experimental results illustrated that the nano-TiO<ce:inf loc=\"post\">2</ce:inf>, which highly beneficial in improving the compressive strength of AARWFSCMs. The additions of 0.50 % ANT and 0.75 % RNT resulted in increments of 5.9 % and 12.8 % in the 28-d compressive strength of AARWFSCMs, respectively. The obtained results provide a new method of utilization of RWFS and improving the sustainability of the construction industry.","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"17 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670435","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":"Mesostructure-induced uncertainty of chloride transport in concrete","authors":"Dingshi Chen, Wenhua Guo, Liujun Guo, Tongjie Ye, Wentao Yin","doi":"10.1016/j.jobe.2024.111337","DOIUrl":"https://doi.org/10.1016/j.jobe.2024.111337","url":null,"abstract":"Chloride-induced corrosion is a primary cause of performance degradation and lifespan attenuation in reinforced concrete (RC) structures in marine and de-icing salt environments. This paper focuses on identifying and modeling the uncertainty of chloride transport induced by the mesoscopic structure of concrete. Utilizing mesoscopic statistics conducted on random concrete specimens with different volume fractions, this investigation elucidates the probabilistic characteristics and the spatial and temporal variation of chloride concentration and diffusion coefficients. Building on the quantitative relationships and Spearman correlations between aggregate characteristic parameters and chloride diffusion coefficients derived from mesoscopic statistics, a prediction model for chloride diffusion coefficients incorporating aggregate volume fractions and particle sizes was developed and validated. On this basis, a mesoscopic probabilistic framework for chloride diffusion coefficients was proposed. The findings reveal the spatial and temporal variability in chloride concentration and diffusion coefficient. The chloride concentration approximates a normal or log-normal distribution, whereas the diffusion coefficient approximates a log-normal distribution. The chloride diffusion coefficient generally shows a noticeable positive Spearman correlation with the maximum and average aggregate sizes and a negative correlation with the aggregate particle number. The research is beneficial for probabilistic chloride transport and lifespan estimation in RC structures.","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"70 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670436","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":"Ten questions on the generation of Typical Solar Radiation Years for daylight simulations: A systematic review","authors":"Mohammed Ayoub","doi":"10.1016/j.jobe.2024.111325","DOIUrl":"https://doi.org/10.1016/j.jobe.2024.111325","url":null,"abstract":"Daylighting studies always bring new requirements of growing sophistications, following almost identical simulation procedure that yields spatiotemporal luminous results. While these simulations require defining a complex set of input variables, architects can easily fine-tune the precision of internal inputs, but external inputs, especially Typical Weather Datasets (TWDs), remain beyond their direct control. The implications of adopting weather data in simulation tools, particularly solar radiation, have thereby been acknowledged, especially when initial approximations of daylighting performance are required during the early stages of design. This gave rise to two distinct, yet related, active areas of research: (i) comparing the capabilities of different TWDs under various daylighting situations, and (ii) generating a specific type of TWDs that depends mainly on solar radiation data, known as Typical Solar Radiation Years (TSRYs). Within the context of daylight simulations, this work represents an unprecedented contribution that systematically investigates the growing directions on the comparison of TWDs (84 comparisons over 11 studies, published between 2013 and 2021) and generation of TSRYs (183 generation attempts over 27 studies, published between 1994 and 2023). Building upon ten established questions, this work puts a particular focus on three hierarchal review scopes: original long-term data, generation process and limitations. This review is conducted with the architects’ nature in mind to clarify nuances of weather datasets and their generation procedures, uncovering knowledge gaps in the related research domain, while sketching future perspectives and missing opportunities. Ultimately, this shall improve the reliability of adopting these datasets in daylight simulations, making them more comprehensible for architects with diverse expertise and backgrounds.","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"74 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670439","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":"Natural fibers as reinforcement of mortar and concrete: A systematic review from Central and South American regions","authors":"Gilberto García, René Cabrera, Julio Rolón, Roberto Pichardo, Carlos Thomas","doi":"10.1016/j.jobe.2024.111267","DOIUrl":"https://doi.org/10.1016/j.jobe.2024.111267","url":null,"abstract":"This study examines recent research on mortar and concrete reinforced with natural fibers (NF). NF are a sustainable, eco-friendly alternative to conventional fibers, offering a way to reduce waste that would otherwise end up in landfills. The diversity of environments across continents provides a wide range of NF to study, and examining representative regions advances the knowledge obtained by enabling comparisons among varied global conditions. A key challenge with NF is their susceptibility to aggressive environments, thus necessitating pretreatment, with alkaline treatment being the most common method to enhance NF properties. As it has been reported, the workability of concrete and mortar decreases as NF content increases, yet this can be mitigated by adding more water or superplasticizers. Despite their benefits, it is advised not to use more than 0.5 % vol. of NF, as higher amounts typically lead to a reduction in the mechanical properties of the result. The durability and microstructure of NF-reinforced materials varies in accordance with test conditions and fiber types, moreover, testing in saline or accelerated aging environments often yields poor results. Further research on NF durability, particularly regarding dry-wet cycles and chloride penetration, is crucial. Environmental analyses show that concrete with NF offers lower energy requirements and reduces carbon footprints. Given the global complexities of NF, systematic studies in other regions are needed for comparative analysis. Nonetheless, using NF as reinforcement helps reduce agricultural waste by diverting it from landfills, aligning with circular economy principles, and promoting sustainability.","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"54 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670455","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":"Experimental analysis on the prototype of decentralised air handling unit with ball-packed regenerator","authors":"Juozas Bielskus, Giedrė Streckienė, Dovydas Rimdžius, Kęstutis Valančius, Violeta Misevičiūtė, Igor Katin","doi":"10.1016/j.jobe.2024.111304","DOIUrl":"https://doi.org/10.1016/j.jobe.2024.111304","url":null,"abstract":"Decentralised, wall mounted ventilation is one of alternative to typical – cross flow or “heat wheel” recovery air handling units (AHU) system when it is not possible to install it. It solves problems such as the need for more space, power consumption of fans, and investment costs. This experimental study aims to analyse the performance of the unique constructed decentralised air handling unit (DAHU) prototype that has a special balls-packed regenerative heat exchanger. The development of the DAHU also aimed to simplify the operation and production of the unit to make it more affordable and easier to manufacture. As the DAHU is constructed from individually sized components, the pressure losses of the diffuser, the regenerator, the screens to hold the balls, the filter and the fan were measured and the actual DAHU airflow was determined. The general operation of the DAHU was tested in a climatic chamber to determine the appropriate cycle times for this type of device, as well as the heat recovery efficiency at different outdoor air temperatures. Five different DAHU operating cycles were analysed. It was found that the duration of supply air must be longer than the duration of extract air to achieve higher efficiency. Therefore, DAHU's subsequent heat exchanger studies were performed for four airflows. The highest DAHU heat recovery efficiency was achieved (above 70 %) with a supply and extract duration of 150 s. It has been found that the efficiency of this DAHU increases with decreasing outdoor air temperature because of the storage properties of the balls. The analysis showed that this type of DAHU could be suitable for use in cooler and colder climates.","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"22 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670447","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}