Production arrangements by US building and non‐building contractors: an update

The paper presents the results of the first phase of a long‐term study that addresses the determinants of the production arrangements by US building (commercial and residential construction) and non‐building contractors (transportation, environmental and industrial construction). Empirical and census data are used to understand the subcontracting and self‐performance practice of the considered contractors. The significant differences in their production arrangements are explained in terms of range of technological requirements and their relative importance within undertaken projects. Building contractors tend to subcontract much of their production, because of the relatively wider range of technological inputs of building projects and liability concerns. On the contrary, non‐building contractors self‐perform much of their production, because of the relatively narrower range of technological inputs of their projects and higher fixed investments in dedicated assets.     

Multivariate evaluation of VOCs in buildings where people with non-specific building-related symptoms perceive health problems and in buildings where they do not

Volatile organic compounds (VOCs) were sampled in buildings where people with non-specific building-related symptoms perceive health problems and in buildings where they do not. In total, nine persons and 34 buildings were included in the study. The obtained VOC data was evaluated using multivariate methods, to investigate possible systematic differences in air quality of 'problem' and 'non-problem' buildings. All individual compounds were included as variables in a multivariate partial least squares (PLS) data analysis. 'Problem' and 'non-problem' buildings separated into two distinct groups, showing that air samples of the two groups of building were chemically different. PRACTICAL IMPLICATIONS: The study showed that there was an identifiable systematic difference in the collected VOC data between buildings causing and not causing problems for people with non-specific building-related symptoms (also called sick building syndrome, SBS). This is an important indication that even such volatile organic compounds that can be sampled by commonly used adsorbents are of importance for the presence of such symptoms. By coordination of procedures for sampling and analysis of VOCs in buildings between laboratories, to get large datasets and more general models, the method can become a useful diagnostic measure in evaluating indoor air and to identify chemical compounds and sources that contribute to SBS problems.     

Fragility analysis of hillside buildings designed for modern seismic design codes

The structural configurations of hillside buildings are significantly different than those observed on flat terrain. To study the effect of often observed structural configurations of hillside buildings, collapse fragility of regular “flat land (FL)” and irregular “split‐foundation (SF)” and “step‐back (SB)” buildings is studied using incremental dynamic analysis. The effects of building height, seismic zone, and near‐ and far‐field sites on collapse fragility are investigated. It is observed that SF and SB hillside buildings exhibit significant torsional effects at the storey just above the uppermost foundation level. In case of FL buildings, collapse occurs due to the flexural failure of beams and columns. On the other hand, in SF and SB buildings, the collapse occurs due to the combined effects of shear failure of short columns and flexural failure of beams and columns in the storey just above the uppermost foundation level. In general, SF buildings are observed to be the most vulnerable, whereas FL buildings are the least vulnerable. It is observed that high‐rise SF and SB buildings show unacceptably high probability of collapse at maximum considered earthquake, in Seismic Zone V and for the near‐field site in Seismic Zone IV.     

Structural design of high‐rise buildings using steel‐framed modules: A case study in Hong Kong

Steel‐framed modular buildings afford certain advantages, such as rapid and high‐quality construction. However, although steel‐framed modules have been adopted in several countries, most of them are limited to low‐to‐medium‐rise structures; modular high‐rise buildings are rare. This study proposes a feasible structural design solution for high‐rise buildings using a steel‐framed modular system. A 31‐story student hostel building in Hong Kong is redesigned as a steel‐framed modular building and used as a case study. The finite element models of the building are formulated, and the structural behaviors under wind and earthquake load scenarios are compared. Moreover, the structural design process used for the 31‐story building is applied to design a hypothetical 40‐story modular building to further examine the proposed design solution. The numerical analysis results indicate that the roof lateral displacements and interstory drift ratios of the redesigned modular building are within the allowable limits of design codes; moreover, the modular connections behave elastically under the most adverse loading scenarios. Accordingly, the proposed solution can be used to design steel‐framed modular buildings of up to 40 stories, while complying with relevant wind and seismic codes.     

Building dampness and mold in European homes in relation to climate,building characteristics and socio‐economic status: The European Community Respiratory Health Survey ECRHS II

We studied dampness and mold in homes in relation to climate, building characteristics and socio‐economic status (SES) across Europe, for 7127 homes in 22 centers. A subsample of 3118 homes was inspected. Multilevel analysis was applied, including age, gender, center, SES, climate, and building factors. Self‐reported water damage (10%), damp spots (21%), and mold (16%) in past year were similar as observed data (19% dampness and 14% mold). Ambient temperature was associated with self‐reported water damage (OR=1.63 per 10°C; 95% CI 1.02‐2.63), damp spots (OR=2.95; 95% CI 1.98‐4.39), and mold (OR=2.28; 95% CI 1.04‐4.67). Precipitation was associated with water damage (OR=1.12 per 100 mm; 95% CI 1.02‐1.23) and damp spots (OR=1.11; 95% CI 1.02‐1.20). Ambient relative air humidity was not associated with indoor dampness and mold. Older buildings had more dampness and mold (P<.001). Manual workers reported less water damage (OR=0.69; 95% CI 0.53‐0.89) but more mold (OR=1.27; 95% CI 1.03‐1.55) as compared to managerial/professional workers. There were correlations between reported and observed data at center level (Spearman rho 0.61 for dampness and 0.73 for mold). In conclusion, high ambient temperature and precipitation and high building age can be risk factors for dampness and mold in homes in Europe.     

Development of a multiple regression model to identify multi-family residential buildings with a high prevalence of sick building syndrome (SBS)

The aim was to develop a multiple logistic regression model to identify multi-family houses with an increase of sick building syndrome (SBS). In Stockholm, 609 multi-family buildings with 14,235 dwellings were selected by stratified random sampling. The response rate was 77%. Multiple logistic regression analysis was applied, adjusting for ownership of the building, building age and size, age, gender, and atopy. Females, subjects with allergy, those above 65 yr, and those in new buildings reported significantly more SBS. Subjects owning their own building reported less SBS, but the relationship between ownership and building age was strong. A regression model, including factors with a high explanatory value was developed. According to the model, 5% of all buildings built before 1961, 13% of those built 1976-1984, and 15% of those built 1985-1990 would have significantly more SBS than expected. In conclusion, SBS is related to personal factors, building age, and ownership of the building. To identify multi-family buildings with more SBS than expected, it is necessary to adjust for ownership and population characteristics.     

Rhinosinusitis and mold as risk factors for asthma symptoms in occupants of a water-damaged building

Abstract Mold exposure in damp buildings is associated with both nasal symptoms and asthma development, but the progression of building-related (BR) rhinosinusitis symptoms to asthma is unstudied. We examined the risk of developing BR-asthma symptoms in relation to prior BR-rhinosinusitis symptoms and microbial exposure among occupants of a damp building. We conducted four cross-sectional health and environmental surveys among occupants of a 20-story water-damaged office building. We defined BR-rhinosinusitis symptom (N?=?131) and comparison (N?=?361) groups from participants' first questionnaire responses. We compared the odds for the development of BR-asthma symptoms between these two groups over the subsequent surveys, using logistic regression models adjusted for demographics, smoking, building tenure, and first-survey exposures to fungi, endotoxin, and ergosterol. The BR-rhinosinusitis symptom group had higher odds for developing BR-asthma symptoms [odds ratio (OR)?=?2.2; 95% confidence interval (CI)?=?1.3-3.6] in any subsequent survey compared to those without BR-rhinosinusitis symptoms. The BR-rhinosinusitis symptom group with higher fungal exposure within the building had an OR of 7.4 (95% CI?=?2.8-19.9) for developing BR-asthma symptoms, compared to the lower fungal exposure group without BR-rhinosinusitis symptoms. Our findings suggest that rhinosinusitis associated with occupancy of water-damaged buildings may be a sentinel for increased risk for asthma onset in such buildings. PRACTICAL IMPLICATIONS: Exposure to mold is associated with the development of asthma in damp building occupants, and rhinitis is known to be a risk factor for asthma. However, there is little information about the degree of risk for the progression of rhinosinusitis to asthma owing to mold exposures in damp buildings. Our study of damp building occupants demonstrates that building-related (BR) rhinosinusitis symptoms were a risk factor for the development of BR asthma symptoms and that exposure to mold (fungi) or other dampness-related agents augments risk for the development of BR asthma symptoms among those with BR rhinosinusitis symptoms. Our findings suggest that occurrence of BR upper respiratory illness in water-damaged buildings may presage future endemic asthma.     

Numerical study of the static and dynamic characteristics of reinforced concrete cassette structures for high‐rise buildings

High‐rise buildings are extensively built in China, and the structure of these buildings is composed of different types of conventional system of which framed structures are more commonly employed. A new cassette structure with advantageous performance properties is proposed. Static and dynamic numerical simulations were applied to investigate the characteristics of this new structure. First, the components and other details are presented. A comparative analysis was conducted between the cassette structure and traditional structures using eight finite models with fiber elements in three different heights. A static pushover analysis and an incremental dynamic analysis were conducted based on 18 near‐ground motion records recommended by the Federal Emergency Management Agency. The seismic characteristics, deformation curve, interstory drift, roof displacement, and fragility curve are investigated. Based on the analysis of the models with three different heights and the variety of seismic records, the economic advantage and application of cassette structures for building industrialization are also discussed.     

Experimental study of across‐wind aerodynamic damping of super high‐rise buildings with aerodynamically modified square cross‐sections

Across‐wind aerodynamic damping ratios are determined from the wind‐induced acceleration responses of 10 aeroelastic models of square super high‐rise buildings in an urban flow condition (exposure category C in the Chinese code) using the random decrement technique. Moreover, the influences of amplitude‐dependent structural damping ratio on the estimation of aerodynamic damping ratio are discussed. The validity of estimated damping is examined through a comparison with previous research achievements. On the basis of the estimated results, the characteristics of the across‐wind aerodynamic damping ratios of modified square high‐rise buildings are studied. The effects of aerodynamically modified cross‐sections, such as chamfered, slotted and tapered cross‐section, on the across‐wind aerodynamic damping ratio are investigated. The results indicate that modifications of cross‐sections are not always effective in suppressing the aeroelastic effects of super high‐rise buildings. Low corner‐cut ratios (chamfer ratios from 5% to 20% and slot ratios from 5% to 10%) and low taper ratio (1%) significantly decrease the magnitudes of absolute aerodynamic damping ratios. However, large modifications of cross‐sections (slot ratio of 20% and taper ratios from 3% to 5%) increase wind‐induced responses by changing the aerodynamic damping ratios. According to the database, empirical aerodynamic damping function parameters are fitted for high‐rise buildings with aerodynamically modified square cross‐sections. Copyright © 2013 John Wiley & Sons, Ltd.     

浅谈绿色建筑

当今社会,为了解决人类生存和可持续发展这两大问题,绿色建筑应运而生。将绿色建筑的设计理念融入其中,是新时代建筑应该具备的能力。本文浅议了绿色建筑概念、内涵,并例举了一些绿色建筑实例。     

谈湖南地区居住建筑节能技术措施

分析当前湖南地区的建筑能耗状况,强调建筑节能的重要意义;针对湖南的气候特点,论述墙体、门窗、屋顶等各部分节能技术措施问题。     

Protein profiles of nasal lavage fluid from individuals with work‐related upper airway symptoms associated with moldy and damp buildings

Upper airway irritation is common among individuals working in moldy and damp buildings. The aim of this study was to investigate effects on the protein composition of the nasal lining fluid. The prevalence of symptoms in relation to work environment was examined in 37 individuals working in two damp buildings. Microbial growth was confirmed in one of the buildings. Nasal lavage fluid was collected from 29 of the exposed subjects and 13 controls, not working in a damp building. Protein profiles were investigated with a proteomic approach and evaluated by multivariate statistical models. Subjects from both workplaces reported upper airway and ocular symptoms. Based on protein profiles, symptomatic subjects in the two workplaces were discriminated from each other and separated from healthy controls. The groups differed in proteins involved in inflammation and host defense. Measurements of innate immunity proteins showed a significant increase in protein S100‐A8 and decrease in SPLUNC1 in subjects from one workplace, while alpha‐1‐antitrypsin was elevated in subjects from the other workplace, compared with healthy controls. The results show that protein profiles in nasal lavage fluid can be used to monitor airway mucosal effects in personnel working in damp buildings and indicate that the profile may be separated when the dampness is associated with the presence of molds.     

谈高层建筑的一些问题

论述了高层建筑的发展和问题以及对目前高层建筑存在的结构、材料、工艺方面的创新与技术的现况和问题进行了分析,提出了一定的建议,并在今后建筑的发展上进一步提出了智能建筑、节能建筑、安全建筑等方向,给出了每种方向发展的概况和前景分析,以促进我国建筑划时代的发展。     

中国建筑节能现状分析

本文根据住宅建筑和公共建筑二方面的能耗数据,分析了中国建筑能源消费水平低、能源浪费严重、用能效率不高、能耗增长潜力大的总体形势,并提出了对策.     

污水处理厂中建筑设计的协调统一

介绍了某污水处理厂的建筑设计,阐述了该污水厂的污水处理区、污泥处理区和生产辅助区的布置,分析了污水处理工艺对建筑的影响,探讨了该厂区的规划建筑特色,积累了污水处理厂的建筑设计经验。     

Calculating extreme surface temperatures

Professor Höglund, of the Division of Building Technology, Royal Institute of Technology, Stockholm, submits a theoretical method of calculating extreme temperatures on the outer surfaces of buildings under non-stationary conditions, taking into account both heat tansfer by convection and exchange of short-wave and long-wave radiation with the surroundings.     

绿色建筑设计分析

文章在阐述绿色建筑的概念、特点的基础上,简要介绍了我国绿色建筑的发展现状和评价标准,最后从节地、节能、节材和节水等4个方面对绿色建筑的设计进行了系统说明。     

绿色智能建筑新技术发展应用

阐述了绿色建筑和智能建筑的概念、特点、以及国内外绿色智能建筑技术现状和研究成果，从社会、经济与环境效益等方面探索绿色智能建筑新技术的发展和应用。旨在推进全社会关注并支持绿色智能建筑的应用，促进可持续发展。     

生态高技建筑浅析

结合生态高技建筑的产生背景,阐述了生态高技建筑的基本特征,介绍了生态高技建筑的发展和实际情况,指出中国建筑师应开拓思路,汲取各种有益的经验,重视设计中的科技含量,积极实践,将理性思考认真的付诸实施,履行好自己的职责。     

非常规突发情况下安置点内围合式临时教育建筑设计

安置点临时教育设施应具备结构坚固、功能合理、形式美观等特点,教授知识的同时,为其提供足够的安全庇护。结合中国现行教育类建筑相关规范及文献,对临时安置点内幼儿园及中小学功能流线、平面布局和空间形态进行分析研究,构建适宜的围合式建筑模型与参数,为完善灾民临时安置点的整体功能配置提供条件。