Unanticipated Bond Failure over Supporting Band Beams in Grouted Post-Tensioned Slab Tendons with Little or No Initial Prestress

After grouting the ducts in a large band beam and one-way slab post-tensioned floor system in a large shopping mall （in excess of 1.5 km2 in plan）, doubts arose concerning the level of initial prestress and the strength and serviceability of the slabs was questioned. To assess the strength of the slabs, it was assumed, as a worst case scenario, that some spans may have been constructed with zero initial prestress. Load tests on prototype specimens, with similar dimensions and reinforcement quantities as the floor slabs, were performed to assess the stress development in initially unstressed, but fully grouted, tendons. Unexpected bond failures occurred at the junctions of slab and band beam where the abrupt change in section depth caused a sudden change in tendon stress. The maximum stress that was developed in the initially unstressed tendons at these locations was about 60% of the strength of the tendons.     

Critical Factors in Financing and Management of Light Rail Transit Systems： Delphi Methodology Approach

In recent years, a large number of LRT （light rail transit） networks and tramways have been built in Spain using the tender system. The rhythm of construction has been such that very few analyses have been carried out and those that have were only partially done because the main participants involved had ulterior motives which impeded their having a critical and independent opinion of the projects carried out. Within this framework, the Delphi methodology presents itself as a very useful instrument, as the intrinsic advantages that it has added to the characteristic that the experts who participate in the project can remain anonymous without detracting value from the conclusions obtained as these are grouped together according to their worth.     

Flexible Pavement Design Simulation Using Mechanistic-Empirical Pavement Design Guide

The KDOT （Kansas Department of Transportation） is currently adopting MEPDG （mechanistic-empirical pavement design guide） to replace the 1993 AASHTO （American Association of State Highway and Transportation Officials） design method. The main objective of this study was to compare flexible pavement design using 1993 AASHTO design guide and MEPDG. Five newly built Superior PERforming Asphalt PAVEments （Superpave）, designed using the 1993 AASHTO Design Guide, were selected as test sections for the design simulation study. Deflection data were collected approximately 8 to 10 weeks after construction using FWD （falling weight deflectometer）. The FWD deflection data were used to back-calculate the pavement layer moduli using three different back-calculation programs. The existing pavement structures were analyzed for a 10-year analysis period. The maximum numbers of years the existing pavement structures will be in a serviceable condition as well as the minimum thicknesses of different layers to serve for 10-years were also determined. Effects of changing subgrade modulus, target distress, and reliability were also investigated. The MEPDG design analysis shows that the 1993 AASHTO Guide-designed flexible pavements do not show the distresses currently observed in Kansas for the 10-year design period. The MEPDG design simulation shows that the thinner the pavement sections, the higher the permanent deformation. The existing pavement structures can serve for more than 20 years as per the MEPDG design analysis if the default failure criteria and nationally-calibrated models are used.     

Infilled Reinforced Concrete Beams for Sustainable Construction

This paper presents a study carried out on infilled reinforced concrete beams for sustainable construction. In reinforced concrete beams, less stressed concrete below neutral axis can be replaced by some light weight material to reduce the weight of the structure and also achieve the economy. The used infilled material is brick. Sustainability can be achieved by replacing the partially used concrete. By saving concrete, the authors save cement, which reduces the green house gases emissions. So it is considered as environment friendly. Since infilled beam acts like a layered member, there needs a theory to analyze it. Method of initial functions is used for the analysis of the infilled RC （reinforced concrete） beams. This method is successfully applied on infilled beam. Results show that physical conditions are verified for infilled beam.     

Economy of RHA （Rice Husk Ash） in Concrete for Low-Cost Housing Delivery in Nigeria

Delivery of housing units in adequate quantity and quality has been the pursuits of individuals and successive governments in Nigeria. Still, the gap between demand and supply is becoming wider on daily basis due to exorbitant cost of building materials that is beyond the reach of average Nigerians. Concrete being the most acceptable construction material is expensive due to high cost of cement. Efforts made to reduce the cost of cement were to no avail, thus there is need to look elsewhere. Past researches showed that substituting cement with 15% of RHA （rice husk ash） in concrete improves the performance of concrete and reduces global warming as a result of emissions from cement production. This paper looks into the effect of using RHA as partial substitute of cement on the cost of a low-cost housing unit. Results showed that cement based construction materials are responsible for 82.58% of the total cost in which cement is responsible for 42%. When 15% RHA was used to substitute cement over N90,000 was saved, amounting to about 7% of the total cost of the building. In addition, depletion of natural resources was reduced.     

Probabilistic Seismic Hazard Assessment for Bridgetown-Barbados,Employing Subduction Interface Characteristic Earthquakes

A new probabilistic seismic hazard analysis was performed for the city of Bridgetown, Barbados, West Indies. Hazard computations have been performed using the standard Cornell-McGuire approach based on the definition of appropriate seismogenic sources and expected maximum magnitudes, the authors take into consideration the possibility of large subduction interface earthquakes of magnitude 8.0-9.0 beneath the Barbados accretionary prism via application of a characteristic model and slip rates. The analysis has been conducted using a standard logic-tree approach. Uniform hazard spectra have been calculated for the 5% of critical damping and the horizontal component of ground motion for rock site conditions setting 5 return periods （95, 475, 975, 2,475 and 4,975 years） and spectral accelerations for 34 structural periods ranging from 0 to 3 s. The disaggregation results suggest that the magnitude-distance pair that dominates the hazard yields M 7.4 and 8.6 and a distance of 42.5 km in the Interface Subduction Zone beneath Barbados for the 475 and 975 years RP （return period）, respectively. An event with an M 8.0 at a distance of 107.5 km in the Intraplate Subduction Zone is the second scenario that dominates the hazard for both 475 and 975 years RP.     

Sustainable Methods and Techniques in Old and New Public Constructions

This article is about the methods and techniques used in the building ＂retrofit＂ in modernist style designed by the architect Affonso Eduardo Reidy in the fifties, and also about the project of the new Rio de Janeiro MIS （Museum of Image and Sound）, under construction, by The North-American office Diller Scofidio ＋ Renfro, both located in the city of Rio de Janeiro. These constructions present a wide view of the concept of sustainability, not commonly used in public buildings in Brazil. In the building designed by Reidy, which belongs to the State of Rio de Janeiro, the regeneration to host the new headquarters of the State Department of Taxation and Finance respected its original characteristics and used smart and sustainable design techniques, as well as recyclable materials. On the other hand, the project of the new museum at Copacabana Beach was entirely planned on sustainable bases and it includes the application of building techniques concerning that purpose. This article presents a study of these two cases and evaluates the techniques and materials used in one another. Observing the principles of sustainability in construction is a pioneering initiative of the State Government. This article aims at making the scientific community aware of the needs of immediate adoption of sustainability techniques in Civil Engineering, not only in the construction of new buildings, but also in the regeneration of the existing ones, as well as the need of imperious adoption of sustainable techniques when it comes to maintainability.     

Use of Geophysical Techniques for the Localization of the Restricting Zones of Permeability in the Bottom of Basin： Forecasting the Zones of Clogging

Measurements of dielectric parameters followed by permeability tests are performed on soil samples of infiltration basin. The dielectric parameters are obtained by TDR （time domain reflectrometry） measurements from which it is found that the measurement of the permittivity, the electrical conductivity and the relaxation time of compacted soil allows the mapping of the values of the coefficient of permeability at the surface of an infiltration basin. With the distribution of the coefficient of permeability, the areas of water stagnation can be detected before the basin filling. The study proves that the TDR measurements for the detection of these zones can be used for the management of infiltration basins for sustainable working and their remediation can be undertaken before the rainy seasons.     

Social Participation in the Context of the Urban Public Space Renewal： The Case of Lagarteiro Neighborhood in Oporto

In 1980, Giancarlo de Carlo wrote in the Perspecta： Yale Journal, ＂An Architecture of the Participation＂. Carlo, proposed a sequence of procedures： the problem definition, the solution and the results evaluation, in all the three steps, the social communities should be integrated in as part of a share and dynamic process. This text corresponds to a new way of understanding the importance of the social communities in the architecture definition. From de Carlo＇s text, the main goal of this paper is to present the results of an intervention in public space renewal of the Lagarteiro neighborhood （in Oporto city） and the relation of this process with the participation of the resident population. The urban context of Lagarteiro＇s neighborhood presented before the intervention the typical and classic signs of disqualification of environmental and urban peripheral areas of resettlement. The term ＂disadvantaged areas＂ is associated with these areas in urban or peri-urban case, was framed in a specific Portuguese policy, called Initiative Critical Neighborhoods. Being a recent intervention, the renewal of the public space in Lagarteiro is a complete case study that allows comprehending the participation phenomenon in nowadays, at the same time that seduces a reflexion about technical and architectural solutions for ＂critical＂ neighborhood.     

A Computer Modeling of the China Central Television Headquarters in Beijing

This paper deals with the computer modeling of structures starting from a point cloud. The CCTV （China Central Television） tower headquarters is the case for study because the shape of this building is non-stellar, concave and multi-connected. It is composed of sowns and chains. The sown is the representation of a horizontal plane formed by dense points. The chain is a planar path modeled by rare points. The CCTV structure is defined only by the three orthogonal Cartesian coordinates of the points. The proposed computer modeling uses a sequence of procedures and the desired outputted 3D model is consistent. The first procedure is devoted to attributing points to their voxel and to estimating three values needed afterwards. The second procedure is devoted to analyzing clusters vertically and horizontally, to preliminarily distinguishing chains from sowns and to generating relational matching. The third procedure is devoted to building closed paths between all chains and all their projections on sowns. The fourth procedure is devoted to connecting points with triangles. The fifth procedure, still being implemented, is devoted to interpolating triangles with triangular splines. The results show it is possible to achieve the 3D model using the above mentioned procedures. These procedures are written, implemented and tested and they form a library of people＇s own software. The code is written using Matlab. It is not possible to obtain the required 3D model if the procedures are applied in the wrong order or one step is skipped. To conclude, it is possible to obtain the computer model of the CCTV using the provided sequence of procedures.     

局部等电位联结常见问题及处理

在建筑电气工程施工中,等电位联结是十分重要的环节,但目前一些不规范做法,难以保证人身安全。建筑物等电位联结分为总等电位联结、局部等电位联结及辅助等电位联结。在建筑物内做等电位联结的目的,是在一定程度上降低建筑内或局部空间内间     

长距离曲线大直径混凝土顶管顶力控制的关键技术研究

地下顶管的顶力控制是制约长距离顶管顶进的重要因素.结合目前国内最大直径且同直径最长距离的顶管工程——上海市污水治理白龙港2.2标顶管工程实践,对顶力控制中的一些关键技术措施,如后靠背制作技术、中继环施工和注浆减阻等进行了研究和探讨,为相关顶管工程积累了经验.     

框架填充墙裂缝控制技术

<正>广州国际体育演艺中心主体育馆为框架-剪力墙结构,停车楼采用框架结构,地下室采用普通混凝土砌块,地下室以上采用MU5加气混凝土砌块,用Mb5砂浆(干拌砂浆)砌筑,砌块干密度为1 200 kg/m3,墙体厚200mm。考虑到根据近年新型墙体填充墙开裂已成为质量通病,造成墙面抹灰饰面裂缝,成为影响工程质量的重要因素,施工前针对填充墙特点,分析裂缝原因,并采取了一系列的预控措施。     

仿砖弹性质感涂料施工工艺及注意事项

仿砖弹性质感涂料是一种装饰效果酷似面砖的水性建筑涂料,以天然级配颗粒彩砂为骨料,进口耐候丙烯酸树脂为胶凝材料,专用助剂为辅料经加工而成,具有天然色泽,高雅庄重。因弹性质感涂料施工简便省时,成本低,具有耐碱、耐污染、防火、防水、无毒、无味、粘结力强、抗冻融性能良好等优点。     

Determination of the Scale of Damage in the Wastewater Tunnels Due to Earthquake： A Case Study

The pre-determination of the effect of earthquake in subsurface structures is gaining importance increasingly. One of the main factors in determination of the damages due to earthquakes in subsurface structures, especially tunnels are horizontal acceleration value. The aim of the study is to put forward the scale of damage due to earthquake in a wastewater tunnel in Istanbul, the most populated city of Turkey, under construction. Possible damage caused by earthquake will be determined by utilizing the information about the route of the wastewater tunnel analyzed in the study.     

厂房预制预应力檩条断落事故原因分析与处理

某新建牛仔布厂由织布车间、浆染车间、锅炉房、配电房、仓库及办公生活用房组成,所有屋盖均采用预制三角形混凝土屋架、预应力混凝土檩条、椽子和平瓦屋面结构。由专业单位设计,外购专业厂家生产的预制屋架、预应力檩条,由业主自行组织施工和构件安装,该厂房于2002年建成投产后未检查保养,2009年9月12日夜间,在正常生产的浆染车间纱缸屋盖处,发生一根预应力檩条突然折断掉落到浆染纱缸内,造成一缸纱损失。整条单机流水线停机的事故。     

地下室外墙型钢三角架单侧支模施工技术

北京金融街E10项目地下4层(地下四层~地下二层层高均为3.7 m,地下一层层高为5.1 m),地上10层,结构形式为框架-剪力墙结构;建筑面积25992 m2,基坑深17.760m,建筑檐高45.000m。本工程场地狭小,地下室东侧外墙距红线1.15~1.7m,南侧外墙距红线0.6~0.7 m,西侧外墙距红线0.56~6.7 m,北侧围墙距红线     

Analyzing Methods of Using Sustainable Development Indicators

Sustainable development indicators, aim to measure sustainable development over longer periods of time. The sustainable development indicators are grouped into 10 subject categories： socioeconomic development, sustainable consumption and production, social inclusion, demographic changes, public health, climate change and energy, sustainable transport, natural resources, global partnership and finally good governance. In this paper, the authors examined a number of researches and compared the methods they used in order to determine the advantages and disadvantages of each method. The methods used a large number of different indicators. The comparison of the indicators could be made through mathematical models and also through theoretical approach.     

广州国际体育演艺中心屋面节能工程施工

<正>广州国际体育演艺中心主体育馆柔性屋面结构层次(从上至下)为:浅灰色TPO卷材防水层,无纺布隔离层,9 mm厚FC高强纤维水泥加强板,200 mm厚酚醛保温板,0.3 mm厚PE材料,9 mm厚FC高强纤维水泥加强     

“居家养老”政策下的老年社区的新发展

摘要：数据显示我国上世纪末已经步入了老龄化社会,而传统的“居家养老”和现代的“机构养老”在满足“安老”需求时都有明显的不足之处。如何寻求新途径以满足大量人口的养老需求已经成为了亟待解决的社会问题。本文针对我国近年来提倡的“居家养老”政策以及现实国情进行了深入剖析,提出将“居家养老”与“老年社区”相结合建设新型老年社区的模式,并对其优势与发展策略进行了分析,为我国养老地产所面临的机遇与挑战提出了切实可行的解决方案。