Breaking concrete by laser

Concrete is a stubborn material to break down and remove, for example in demolition work, but its low thermal conductivity may make it susceptible to breaking by laser. The authors describe here tests with different methods, notably by thermal shock, and forecast the development of a portable carbon dioxide laser tool for site use.     

SK高强无收缩灌浆料研制与应用

SK高强无收缩灌浆料可用于配制灌浆材料 (如灌制地脚螺栓、铆固等 ) ,结构自防水 ,自流平地面 ,屋面材料的施工及结构加固等 ;它施工快速、方便 ,价格低。高强无收缩灌浆料研制、性能分析以及应用     

境由幻出——古典园林的虚实之美

园林是时空的艺术；造园处处涉及虚实。实是指物境的建造，而虚则可指情弹与意境的开拓。化实为虚，虚实相生，由触景生情到情景交融，这正是中国园林艺术的魅力之所在。该文就中国园林的虚实之美进行了论述。     

The shock Hugoniot of Tuffisitic Kimberlite Breccia

The Hugoniot of a material represents the response to high-rate loading at pressures associated with those produced by blasting charges. The shock Hugoniot curve of a kimberlite, Tuffisitic Kimberlite Breccia (TKB), has been determined between 0.3 and 8.4 GPa using plate impact experiments. The dynamic shear response of TKB is reported for impact stresses between 1.1 and 3.2 GPa. Longitudinal and lateral stress measurements were made using embedded manganin gauges and VISAR in material shocked to a state of uniaxial strain. The shock response of TKB reveals a relatively weak material with no clear Hugoniot Elastic Limit (HEL) in the longitudinal stress measurements. The lateral stress measurements suggest an HEL between 0.6 and 0.9 GPa. Inelastic deformation is observed at all stresses due to a combination of volume compaction and brittle failure. The current data have been compared with similar reports in the literature and theory in order to accurately describe the response of this inhomogeneous geological material.     

高性能复合砂浆薄层加固RC梁的耐火极限试验研究

高性能复合砂浆钢筋网薄层(简称HPFL)加固混凝土构件是一种新型的加固方法,该方法采用的高性能复合砂浆为无机材料,具有众多优良特点。为研究HPFL加固RC梁在高温-外力共同作用时剪切销钉对界面粘结性能的影响,对6根三面U形(在梁的受拉面和侧面进行加固)加固RC梁进行了高温试验,所有加固试件分为三组,第一组两根试件未植入剪切销钉,第二组两根试件植入剪切销钉,剪切销钉间距较大,第三组两根试件也植入剪切销钉,剪切销钉间距较小。试验后,比较它们的耐火极限、跨中挠度和破坏形态,分析界面在高温时的破坏机理。试验结果说明:植入剪切销钉可以非常显著地改善界面在高温时的粘结性能,试件在高温时的耐火性能得到很大的提高。     

Healthy Port Futures: Rethinking Sediments for Rivermouth Landscapes

Throughout the Great Lakes, port cities are often located on the rivermouth and where rivermouths once sorted, shaped, and moved the riverine sediment into the lake. Their current use as industrial navigation channels requires cyclical mechanical maintenance dredging. Past sediment management practices have either placed the riverine sediment nearshore in confined disposal facilities (CDFs) or out in deeper open water. Both practices remove the sediment from the nearshore system, preventing its potential use in coastal protection, habitat creation, wave attenuation, and sediment nourishment. However, novel rivermouth wetlands can draw from both strategies of containment (as in a CDF) and cost-efficiency of non-containment (open lake disposal) to allow for the processing and use of sediment. This article will describe one such attempt, conducted by the Great Lakes Protection Fund-supported Healthy Port Futures project. Through a collaborative design-research process, Healthy Port Futures used a range of tools to generate, speculate, model, visualize, and test wetland forms under a range of social, ecological, and hydrological conditions. This project, understood colloquially as “the Crescent,” proposed a semi-circular, partially open-cell wetland design as a response to the complexity of rivermouth conditions. Throughout this design-research process, the project sought to acknowledge uncertainty, assess risk, and explore a range of outcomes in order to redefine the public expectations around wetland creation and restoration, and reimagine innovation along the Great Lakes coast.     

基于数字图像的岩石非均匀性表征技术及初步应用

依据数字图像处理理论,研发出一种基于数字图像的岩石非均匀性表征技术。该技术描述的非均匀性更接近于岩石的真实非均匀性,并将其映射到有限元网格中,与原有的岩石破裂过程分析系统（RFPA）相结合,建立一种更能准确反映岩石细观结构的数值模型,从而弥补传统数值方法所采用统计理论表征岩石非均匀特性的不足。通过对2种常规试验（单轴压缩和单轴直接拉伸）的数值模拟,再现花岗岩试件在荷载作用下的真实破裂过程。数值模拟结果表明：岩石的细观结构对岩石的力学性能和破坏过程有重要影响。该方法为进一步研究岩石、混凝土等非均质材料的力学特性和破坏机制提供一种新的手段。     

Response: Contrasting US and European Findings on Poverty Neighbourhoods

The US literature has produced more studies and thus more data on urban poverty areas. With respect to theory, the volume edited by Lynn & McGeary (1990) and the work of Wilson (1987) has been of great influence. The latter has been the basis of much work in Europe, such as the studies by Wacquant (1993) and Friedrichs (1998a). This paper will briefly review the similarities and differences between the US and the European findings.     

Critical Practice: Protocol for a Fused Technology

Software created for architecture often presumes a certain repertoire of design intents; software appropriated from other fields does not make such presumptions but introduces translation difficulties into material logics. Aaron Sprecher, Chandler Ahrens and Eran Neuman describe how their collaborative design group, Open Source Architecture (O-S-A), has worked with structural engineers and software developers to create a computational protocol based on a stochastic evolutionary topological optimisation algorithm. This procedure allows architectural designers to work with complex geometries previously limited to the expertise of engineering. In addition to taking the form of a distributed network spanning New York, Los Angeles and Tel Aviv, O-S-A opens the possibility for various disciplines (computer science, structural engineering, architectural design) to work with a fluidity and commonality not previously possible. Like the work of RSG (also featured in this issue), here design begins with the construction of a software environment in which a project can occur, and which merges previously distinct areas of expertise. Copyright © 2006 John Wiley & Sons, Ltd.     

中西方绅士化研究进展及其对我国城市规划的启示

绅士化是1960年代产生的一种城市社会地理现象,经过几十年的发展,绅士化研究为城市发展提供了很多借鉴.本文首先时西方绅士化的概念及其发展进行了描述,指出西方绅士化的概念已经在最初的基础上有了改进,并且对西方目前存在的各种绅士化现象进行了分类;其次回顾了我国时绅士化研究的进展和所取得的成果;最后,分析了绅士化运动对我国城市建设带来的正负两方面的影响,并据此对我国城市规划建设和发展提出了建议.     

Field seaming of VLDPE

Within the past four years, a new geomembrane material has been introduced and used on a number of projects including landfill closure systems. The material, which is the subject of this paper, is very low density polyethylene (VLDPE).

This paper will describe the material and its physical/mechanical properties and make comparison to other geomembranes such as polyvinyl chloride (PVC) and high density polyethylene (HDPE). An additional focus is the method for field seaming of VLDPE. The hot wedge method is generally used in a dual track configuration. Details of this particular seaming method are described along with our expriences to date.     

Evolving Patterns: Correlated Systems of Interaction

Over the last four decades, the onset of computation has enabled architects and designers to employ generative patterns in their exploration of emergent social, material and spatial systems. Theodore Spyropoulos provides an overview of the field and discusses how it has been developed by the Design Research Lab (DRL) at the Architectural Association into an ‘Adaptive Ecologies’ agenda. In the context of parametric urbanism, the DRL has explored models of living through behavioural patterns found in nature, examining the role of the singular and the collective. Copyright © 2009 John Wiley & Sons, Ltd.     

论项目团队的构建

项目团队作为施工企业的主要组织形式,已经广泛应用于各施工项目中。本文阐明了项目团队的基本特征,探讨了项目团队的构建框架及团队精神的培育,为项目团队建设提供了依据和启示。     

氯离子在火灾后混凝土中的扩散模型

研究了火灾后混凝土结构中的氟离子分布及其随时间的扩散机理，建立了相应的数学模型，并采用现有的有关资料对模型的合理性进行验证，分析了该模型参数的灵敏度，从而为火灾后混凝土结构的耐久性评估提供了理论依据．     

DNA disPLAY: Programmable Bioactive Materials Using CNC Patterning

2D, 3D and 4D printing are fertile areas for design and material experimentation, and thus the architectural detail in the future. Here Skylar Tibbits , along with his collaborators - Lina Kara'in (MIT Self-Assembly Lab) , Jose Gomez-Marquez, Anna Young and Joaquin Navarro (Little Devices Lab, MIT), Lee Gehrke, Helena de Puig and Justina Tam (Gehrke Lab, MIT), and Joseph Schaeffer and Carlos Olguin (Autodesk Inc) - describe the development of DNAdisPLAY: a project that created a physical prototype and design workflow for 2D bioprinting, resulting in the development of software, hardware and printed DNA patterns on paper.     

Evaluating a mass transfer model for the dissolution of organics from oil films into water

A mass-transfer model analogous to one used to describe the volatilization of organics from natural waters was used to describe the dissolution of constituent organics from a floating oil film into the underlying water. The mass flux of a material across the oil-water interface was depicted using an oil-phase mass-transfer coefficient, k_o a water-phase mass-transfer coefficient, k_w, a partition coefficient, P, describing the equilibrium partitioning of a substance between oil and water, and the concentrations of the substance in the oil and water, C_o and C_w, in the following expression: Rates of dissoltion were observed to vary with properties of the solute, P, the oil (viscosity, P, oil depth) and the environment (oil and water mixing, water depth). The observed rates of dissolution of chemicals from a low-viscosity oil (heptane) varied by a factor of 10⁴ between the most rapidly and most slowly dissolving materials.     

Management for engineers: the contribution of distance learning

These days, more engineers (and their employers) are seeing the need for a continuing programme of development of their management skills, as they assume increasing management responsibilities in their organisations. Here, the authors describe the IEE's Distance Learning Programme which has been tailored to respond to this need by providing a wide range of relevant and up-to-date learning material     

Q460高强角钢单边连接压杆有限元分析

随着我国电力工业的发展,使用高强度钢材已成为一种现实需求,为研究Q460高强角钢力学性能,进行了48根Q460高强角钢单边连接压杆试验,并建立有限元分析模型,有限元分析考虑了几何大变形、材料非线性和接触非线性。有限元采用的构件几何尺寸、材料特性等参数和加载过程均与试验相同,对比显示有限元分析结果和试验结果吻合较好。研究表明,Q460高强角钢单边连接压杆的极限承载力不只跟构件的长细比、截面规格有关系,还受连接板厚度、宽厚比的影响。     

Research and Development in Methods of Soakaway Design

Soakaways have been a traditional method of disposal of stormwater for decades, and their usage has mainly been determined by the absence of a convenient watercourse, drain, or sewer into which to discharge runoff arising from roofs and paved surfaces. Today, soakaways are still being installed at a rate of tens of thousands per annum, despite the extensive storm-sewer systems in the UK. It is therefore surprising that little systematic research and development has been undertaken into their design and performance, or into the appropriate forms of maintenance to be conducted to extend operational life.
The paper briefly describes the recent research into, and design approaches for, the sizing of soakaways. An example is given of the use of Building Research Establishment Digest 365 to review alternative soakaway designs and to assess the cost implications. Some field data are reported which (a) illustrate the seasonal variability and difficulties of determination of the soil infiltration rate, and (b) provide some insight into the pollution issues from the use of soakaways.