HBRC Journal最新文献_第3页

The impact of densification and orientation manipulation on outdoor thermal comfort at social housing in arid regions: a sensitivity analysis 干旱地区社会住房的密度和朝向对室外热舒适度的影响：敏感性分析

HBRC Journal Pub Date : 2023-11-30 DOI: 10.1080/16874048.2023.2287776

Mariam A. Adly, Hatem Mahmoud, Omar M. Galal

{"title":"The impact of densification and orientation manipulation on outdoor thermal comfort at social housing in arid regions: a sensitivity analysis","authors":"Mariam A. Adly, Hatem Mahmoud, Omar M. Galal","doi":"10.1080/16874048.2023.2287776","DOIUrl":"https://doi.org/10.1080/16874048.2023.2287776","url":null,"abstract":"ABSTRACT Many developing countries are experiencing rapid urban growth, resulting in a high demand for social housing schemes. In Egypt, newly built communities and potential extensions are incompatible with its hot climate due to low aspect ratios, high sky view factors values (SVF) and less shaded areas, which negatively affect outdoor thermal comfort at the pedestrian level. This study aims to find a relationship between density (represented in SVF), Physiological Equivalent Temperature (PET) and orientation through a sensitivity analysis to improve the thermal comfort of outdoor spaces in new cities. The research was held on the peakiest summer day using a validated ENVI-met simulation model for a residential area in New October city. The simulation results of 36 scenarios with a total of 37,138 spatial grids were examined through sensitivity analysis to quantify the impact of densification parameters like building coverage ratio, floor area ratio, building height variation, and orientation on PET. PET was found to be more sensitive to densification in cardinal directions. With Higher mid-range densities PET at cardinal orientation reached up to 10℃ higher than in diagonal. Also, the results revealed that optimizing density and building heights could improve average PET (08:00 to 18:00) in diagonal orientation with up to 8℃ in the mid-range densities. However, orientation is insignificant in low densities. Out of the tested parameters, densification was found to be the most impactful strategy than height variation. These results can aid in developing public and private housing schemes that are more climate responsive.","PeriodicalId":502312,"journal":{"name":"HBRC Journal","volume":"250 ","pages":"523 - 541"},"PeriodicalIF":0.0,"publicationDate":"2023-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139204766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Comparative analysis of thermal performance for precast panel systems with conventional and innovative insulation materials 使用传统和创新保温材料的预制板系统保温性能对比分析

HBRC Journal Pub Date : 2023-11-29 DOI: 10.1080/16874048.2023.2283294

Aya Hamdy Said Ragab, Eman Mohamed Eid Attiah, Mohammed Adel Shebl, Amal Abdel Hady Nasser

{"title":"Comparative analysis of thermal performance for precast panel systems with conventional and innovative insulation materials","authors":"Aya Hamdy Said Ragab, Eman Mohamed Eid Attiah, Mohammed Adel Shebl, Amal Abdel Hady Nasser","doi":"10.1080/16874048.2023.2283294","DOIUrl":"https://doi.org/10.1080/16874048.2023.2283294","url":null,"abstract":"ABSTRACT Precast facades are one of the most popular technology solutions featuring high-quality implementation and installation. They consist of three layers, both the external and internal layers are concrete composite, where the core is a thermal insulation material. This study explores the thermal performance improvement of these locally manufactured panels and evaluates their effectiveness in supporting building sustainability and energy saving. The study is performed experimentally. Leca and Addipor aggregates were used as a replacement of mix aggregate to produce lightweight heat-insulating concrete. Compressive strength equals 15MPa were taken for both Leca and Addipor replacement ratio. The study simulates several sections of precast concrete panels using ANSYS. Proposed concrete models with traditional and innovative thermal insulation materials, which are Expanded Polystyrene Foam (EPS), Extruded Polystyrene Foam (XPS), Rigid polyurethane foam (PU) and Vacuum insulation panels (VIPs), were analyzed. In addition, a virtual room space was simulated thermally using the previous sections to perform thermal simulations, as rate of heat transfer and amount of energy savings. The use of polyurethane foam (PU) as a new thermal insulation material and vacuum insulation panels (VIP) as an innovative thermal insulation material helps to reduce energy consumption by a rate of 143% and 700% of conventional insulation materials (EPS), respectively. It achieves internal thermal comfort and supports building sustainability.","PeriodicalId":502312,"journal":{"name":"HBRC Journal","volume":"6 1","pages":"427 - 452"},"PeriodicalIF":0.0,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139214779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optimization and surface functionalization of carbon nanotubes using different hierarchical metal oxide nanoparticles 使用不同层次的金属氧化物纳米粒子优化碳纳米管并使其表面功能化

HBRC Journal Pub Date : 2023-11-28 DOI: 10.1080/16874048.2023.2287768

Mohamed Morsy, I. Gomaa, Walaa M. Taha, A. Elhamid, Hamada Shoukry, M. Mokhtar

{"title":"Optimization and surface functionalization of carbon nanotubes using different hierarchical metal oxide nanoparticles","authors":"Mohamed Morsy, I. Gomaa, Walaa M. Taha, A. Elhamid, Hamada Shoukry, M. Mokhtar","doi":"10.1080/16874048.2023.2287768","DOIUrl":"https://doi.org/10.1080/16874048.2023.2287768","url":null,"abstract":"ABSTRACT The metal oxide surface-functionalized CNTs have attracted the interest of many researchers worldwide because of their different and feast important applications. In this investigation, two different hierarchical metal oxide nanoparticles Zinc oxide (ZnO) and Cobalt oxide (Co3O4) have been loaded on the external surface of multi-walled carbon nano tubes (MWCNTs) following the hydrothermal process by using the cetyltrimethylammonium bromide (CTAB) surfactant. To assess the quality of preparation, the prepared nano composites were verified by utilizing various techniques, including scanning electron microscopy (SEM), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy. It was proven by the obtained results that, ZnO and Co3O4 are uniformly and homogenously loaded on the surface of MWCNTs, as presented in the SEM and HR-TEM images. Also, The FTIR confirms the presence of absorption bands related to the presence of CNTs, ZnO and Co3O4 nano materials. in addition, The HRTEM imgaes and corresponding SAED demonstrate the presence of nano particles (ZnO and Co3O4) on the external surface of MWCNTs. furthermore, ZnO particles have a hexagonal platelet structure, and their thickness increases as the amount of CTAB increases. Moreover, the XRD diffraction pattern confirms the crystalline structure of the loaded nanoparticles.","PeriodicalId":502312,"journal":{"name":"HBRC Journal","volume":"29 1","pages":"509 - 521"},"PeriodicalIF":0.0,"publicationDate":"2023-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139219116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

3D FE modeling of a complex multi-stage foundation underpinning for a high-rise building 高层建筑复杂多级地基基础的 3D FE 建模

HBRC Journal Pub Date : 2023-11-27 DOI: 10.1080/16874048.2023.2283277

Amr A. Hemada

{"title":"3D FE modeling of a complex multi-stage foundation underpinning for a high-rise building","authors":"Amr A. Hemada","doi":"10.1080/16874048.2023.2283277","DOIUrl":"https://doi.org/10.1080/16874048.2023.2283277","url":null,"abstract":"ABSTRACT The piled foundation of an existing high-rise building in Cairo was assessed as inadequate. The building foundation consists of 370 piles arranged below the columns and walls. The building was constructed in 1977, and up to the start of this investigation in 2014, it was just a concrete skeleton without finishing. The existing foundation was subjected to underpinning in 1985 using micropiles to support new lateral load-resisting elements proposed by the project structural consultant. According to the new Egyptian codes of practice, underpinned foundations are still considered inadequate and it was proposed to add additional micropiles with a raft connecting the different pile groups. This paper presents the 3D FE modeling for this complex multi-stage foundation underpinning considering the construction sequence and the different interactions between the original piles, existing and proposed groups of micropiles, supporting soil and the capping raft. The load transferred by direct contact between the raft and the soil is also investigated. Available detailed geotechnical investigation and evaluation of the available micropiles loading tests were used to estimate the parameters of soil and pile−soil interface. The advanced 3D FE model is used to ensure that the proposed number of additional micropiles satisfies the required safety and stability. The outcome of the analysis proved to conservatively satisfy safety requirements. The raft transferred a considerable part of the total load directly to the soil, hence increasing the capacity of the combined piled raft foundation system.","PeriodicalId":502312,"journal":{"name":"HBRC Journal","volume":"357 1","pages":"393 - 407"},"PeriodicalIF":0.0,"publicationDate":"2023-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139230516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Behavior of unbonded pre-stressing concrete beams with thermal insulation coating 带隔热涂层的无粘结预应力混凝土梁的性能

HBRC Journal Pub Date : 2023-11-27 DOI: 10.1080/16874048.2023.2285111

Mohamed Talaat, Ayman Moustafa, M. Kohail, Ayman Khalil

{"title":"Behavior of unbonded pre-stressing concrete beams with thermal insulation coating","authors":"Mohamed Talaat, Ayman Moustafa, M. Kohail, Ayman Khalil","doi":"10.1080/16874048.2023.2285111","DOIUrl":"https://doi.org/10.1080/16874048.2023.2285111","url":null,"abstract":"ABSTRACT Pre-stressing concrete is commonly used in construction. One of the challenges that pre-stressing concrete (PC) faces is that fire exposure reduces the strength and serviceability of PC elements, which requires unique design considerations. The pre-stressing strands are more sensitive to high-temperature, deform larger than mild steel, and break quicker. This research investigates the thermal and structural response of totally unbonded pre-stressing T-beams subjected to increased temperatures and continuous service loads. Thermal coating was proposed to avoid damage and load carrying capacity reduction under fire loading. Seven medium-sized post-tensioned concrete beams were tested in a fire exposure (600°C for 3 h) in order to examine the effect of the following variables: presence of thermal coating, the use of different pre-stressing ratios, increasing the concrete cover, and studying the fire effect at the end anchor, which represents the weakest point at the unbonded system. The proposed insulating technique improved pre-stressing beam behavior during fire exposure by improving crack distribution and lowering strength loss. The thermally insulated beam with a high pre-stressing ratio attained 99.3% of the control specimen load carrying capacity, compared to 86% for the unprotected beam. The deflection of the thermally isolated beam was 7.8 mm, compared to 22.7 mm for the unprotected specimen after 180 min of fire exposure. The use of low pre-stressing ratio caused the insulated pre-stressing strands to rapidly deform with low increases in temperature, which caused rapid crack formation.","PeriodicalId":502312,"journal":{"name":"HBRC Journal","volume":"102 1","pages":"409 - 425"},"PeriodicalIF":0.0,"publicationDate":"2023-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139229859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Determining the levels of urban agriculture to meet the desired goals of urban development 确定城市农业的水平，以实现城市发展的预期目标

HBRC Journal Pub Date : 2023-11-16 DOI: 10.1080/16874048.2023.2275060

Mai Mahmoud Mourad, Rowida Mohamed Kamel, Raghad Mofeed Ibrahim

{"title":"Determining the levels of urban agriculture to meet the desired goals of urban development","authors":"Mai Mahmoud Mourad, Rowida Mohamed Kamel, Raghad Mofeed Ibrahim","doi":"10.1080/16874048.2023.2275060","DOIUrl":"https://doi.org/10.1080/16874048.2023.2275060","url":null,"abstract":"ABSTRACT Urban agriculture is essential to support sustainable urban development by achieving the urban agriculture goals (UAGs), which are economic, environmental, social, agricultural, esthetic and humanitarian goals. Urban agriculture includes three main levels, starting with precision urban agriculture, followed by the level of small urban agriculture, and then gradually moving to medium and large urban agriculture. These different levels are tightly connected to what UAGs aims to achievement. The research aims to providing a framework for selecting the appropriate level of urban agriculture according to the urban agriculture required goals, through finding the interrelationship between urban agriculture levels (UALs) and the related urban agriculture goals (UAGs) for each level. The research depends on experts’ questionnaires to conclude the varying relationships of the impacts of urban agriculture levels which are micro, small, and medium levels on the urban agriculture goals, which have been classified into groups, according to the most and the least affected by the UALs. Where the small scale of urban agriculture levels came in the lead of supporting the achievement of the social, environmental, and urban esthetic urban agriculture goals, however the medium- to large urban agriculture level came in the lead of supporting the achievement of agricultural and economic urban agriculture goals. This result will be beneficial to decision-makers in distributions of urban agriculture in deferent levels to determine the most appropriate level of urban agriculture in cities and residential complexes, according to the desired urban agriculture goals, according to the experts’ results.","PeriodicalId":502312,"journal":{"name":"HBRC Journal","volume":"201 1","pages":"373 - 391"},"PeriodicalIF":0.0,"publicationDate":"2023-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139270527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0