谈对混凝土拌和物工作性的认识

对混凝土拌和物的工作性及其测定作了论述,并分析了影响混凝土拌和物工作性的主要因素,在此基础上提出了改善混凝土拌和物工作性的措施,以使硬化后的混凝土满足设计强度及耐久性要求。     

页岩陶粒对大流动度轻集料混凝土拌合物工作性的影响研究

主要研究轻集料粒径、粒型、吸水率、预湿处理等对大流动度轻集料混凝土拌合物工作性的影响。研究结果表明:随着陶粒最大粒径的减小,流动性逐渐降低,但抗离析性能逐渐增强;对于大流动度轻集料混凝土,以普通型陶粒配制的轻集料混凝土拌合物更容易保证匀质性;对于吸水率大的陶粒,可通过延长预湿处理时间来减小轻集料混凝土拌合物的离析度,减少坍落度经时损失;对于吸水率小的陶粒,可不经预湿处理即可达到较高的流动性。     

轻集料混凝土宏观现象的微观机理分析

通过电镜扫描的方法,对轻集料混凝土的微观机理进行了试验研究,从微观角度对轻集料混凝土的宏观现象进行了分析,阐述了轻集料混凝土良好工作性的产生原因,从而进一步推广轻集料混凝土的应用。     

橡胶微粒掺量对塑性混凝土性能的影响

采用对比试验方法,测试了橡胶微粒掺量为0-14.30%（体积分数,下同）的塑性混凝土工作性、强度、弹性模量、渗透系数.结果表明,当橡胶微粒超量取代膨润土且其掺量达到8.90%之后,塑性混凝土的强度和弹性模量随着橡胶微粒掺量的增加而明显降低;当橡胶微粒部分取代黏土后,塑性混凝土的强度和弹性模量并没有降低,其拌和物的工作性和施工的可操作性得到明显改善;当橡胶微粒超量取代膨润土并部分取代黏土,且其掺量达到8.64%时,塑性混凝土拌和物的工作性及混凝土强度、弹性模量和渗透系数都能满足防渗墙工程设计要求.     

钢纤维增强自燃煤矸石轻集料混凝土试验研究

针对煤矸石占用大量耕地并对矿区生态环境造成的污染问题,参照国标,对辽宁省阜新市高德矿排放的自燃煤矸石进行了化学组成、耐久性及有害物质含量、物理力学性能的检测,发现其各项指标均满足国家对轻集料标准的要求.为此,将自燃煤矸石破碎作轻粗集料、钢纤维作增强材料,设计了5组钢纤维掺量的混凝土试件,进行了拌和物工作性及均质性,硬化后抗压强度、劈拉强度和抗折强度的试验,并且以试验结果为样本,建立了钢纤维掺量与混凝土强度之间的定量关系式.研究结果表明,当钢纤维掺量小于2%(体积分数)时,随钢纤维掺量增加,自燃煤矸石轻集料混凝土的抗压?劈拉和抗折强度都有不同程度的提高,其中以抗折强度的增长最为显著.另外,对上述现象进行了机理分析.     

混凝土强度与集料组分试验研究

通过对混凝土集料在不同组分的条件下影响混凝土工作性能试验研究,重点阐释了混凝土拌和物中粗集料的品质、最佳粒径、砂率等集料在不同组分工作条件下使混凝土抗压强度值发生了明显的改变。试验结果表明:混凝土拌和物中集料的组成与变化状况对混凝土的抗压强度有着较大的影响。     

矿物掺和料对轻集料混凝土性能的影响

通过近年来矿物掺和料在轻集料混凝土中的研究和应用,总结了矿物掺和料对轻集料混凝土的工作性、力学性能和耐久性方面的影响,通过分析作用机理得知使用矿物掺和料能大大提高轻集料混凝土的塌落度、强度、抗渗性和抗冻性。同时,矿物掺和料在轻集料混凝土中的应用还有效解决粉煤灰和矿渣的综合利用问题,实现资源利用的可持续发展。     

大流动性高性能轻集料混凝土的试验研究

为设计出具有大流动性的高性能轻集料混凝土,分别研究了胶凝材料用量、粉煤灰取代量和体积砂率等因素对轻集料混凝土工作性、密度和抗压强度的影响规律;采用700级粘土陶粒可配制密度等级为1700级,坍落度达200mm的CL30轻集料混凝土.该混凝土28d收缩率仅为45.5×10-6,快速冻融循环可超过300次,RCM法测得的氯离子扩散系数为2.59×10-12m2/s;而且工作性好,基本克服了陶粒的上浮问题.     

泵送钢纤维轻集料混凝土的性能及施工技术

以轻集料为主要原料,研制了钢纤维高强轻集料桥面混凝土,对其容重、工作性能、力学性能和弯曲韧性进行了研究,提出了桥面钢纤维轻集料混凝土的施工工艺流程和施工质量控制等技术要点.     

高性能混凝土的原材料控制

高性能混凝土是一种高强度、长耐久性及高工作性的新型混凝土,其高性能品质需要从源头开始,通过对原材料的品质进行严格控制,对混凝土拌合过程进行进行全过程控制及现场施工控制来共同实现的。高性能混凝土使用的原材料除了普通混凝土所需的水、水泥、粗集料、细集料（砂）之外,还必须掺入高效减水剂和一定量具有活性的超细矿物质掺合物,     

居住区地表种植面积保障技术

本研究的目的是在现有的城市土地资源不变的情况下，在不改变现有的居住区规划设计规范条件下，通过相对简单的技术手段，探索增加居住区地表种植面积的有效措施，并用这些方法使我国已经建成的优秀居住区能新增加的绿化地表种植面积约占小区总面积的２．７％，对这我国城市居住住区环境建设的可持续发展有着积极意义。     

土的基本特性及本构关系

面对土的外延持续拓展、内涵不断深化、本构模拟精度要求日趋提升的挑战,土的基本特性与本构关系研究要回归初心,面向工程需求,聚焦于达到工程分析精度而需要刻画的土的宏细观一体化特性,称作土的工程本征性。工程本征性主要有三相性、各向异性、摩擦性和剪胀性等几个方面,其内涵和发展趋势基于研究现状进行探讨。研究与刻画土的工程本征性时,应基于一体化的思路,注重细观特征和宏观特性刻画精度的均衡性,即：宏观层面的研究指导在细观层面有目标的观测,而不需要无止境的追求各类细观层面的细节;细观层面的研究为宏观层面的刻画提供充分依据,从而克服脱离细观机理的唯象假设。以土的工程本征性为核心探讨土的基本特性与本构关系研究的宏细观一体化建模方法,结合强度理论和多过程耦合模型等课题探讨研究现状与发展趋势。简要回顾本构理论研究的重要进展,指出土的本构理论研究已经具备深厚积累,以期为宏细观一体化的工程本征性研究奠定坚实的基础。     

Residential building damage and natural perils: Australian examples and issues

The most important natural perils in Australia are tropical cyclones, earthquakes, bushfires, thunderstorms, floods, landslides and tsunamis. However, as far as residential buildings are concerned, the correct relative order of importance depends on the frames of reference used. Certainly, meteorological perils are more significant than geological hazards. Residential building damage produced by the most important natural hazards is assessed. Governance is shown to be poorly related to actual risk. Tropical cyclone wind-loading codes are amongst the best in the world, but the more limited potential for storm surge damage is largely ignored. While land-use regulations are strong in some states, almost no attention has been paid to appropriate building materials for flood-prone properties. Hail is probably the most important peril along the populated south-eastern seaboard, but no regulations govern roofing materials. Other issues relating to the present understanding of damage to buildings are raised.     

Debating the future of comfort: environmental sustainability, energy consumption and the indoor environment

Vast quantities of energy are consumed in heating and cooling to provide what are now regarded as acceptable standards of thermal comfort. In the UK as in a number of other countries, there is a real danger that responses in anticipation of global warming and climate change - including growing reliance on air-conditioning - will increase energy demand and CO₂ emissions even further. This is an appropriate moment to reflect on the history and future of comfort, both as an idea and as a material reality. Based on interviews and discussions with UK policy makers and building practitioners involved in specifying and constructing what will become the indoor environments of the future, four possible scenarios are identified each with different implications for energy and resource consumption. By actively promoting debate about the indoor environment and associated ways of life, it may yet be possible to avoid becoming locked into social and technical trajectories that are ultimately unsustainable. The aim of this paper is to inspire and initiate just such a discussion through demonstrating that comfort is a highly negotiable socio-cultural construct.     

和谐与个性——浅析北京应用物理及计算数学研究所信息楼的设计

对北京应用物理及计算数学研究所信息楼的建筑方案进行了总结分析,阐述了它在与规划的协调、功能、造型、细部设计等方面的设计特点,也指出了一些存在的问题。     

Environmental impact analysis for typical office facades

The design of a building facade influences internal thermal and lighting conditions and energy use associated with the provision of these conditions. Key decisions about the building facade are usually taken during the concept design stage of a building, while decisions about the method of providing the environmental conditions are often made later in the design process. This dilemma is addressed by the development of a concept design tool that allows the design team to investigate the effect of facade design on the resulting internal environmental conditions, energy use and environmental impact. The concept design tool was developed by performing detailed thermal, lighting and environmental modelling for a number of generic office building facade designs and a range of parameters that affect directly the environmental performance of an office building. The results are presented in a user-friendly interface requiring a minimum number of inputs. Key parameter outputs (such as temperature, lighting levels, heating/cooling energy demand, embodied energy and eco-points) can then be viewed, while a more detailed analysis can also be created for specified facade designs. A parametric analysis of the summary result outputs for selected facade parameters indicates that natural ventilation and cooling can reduce the environmental impact of offices by up to 16%, although heating energy demand could increase significantly. Improving the construction standard of the facade and reducing the internal heat loads can reduce the environmental impact by up to 22%. Use of this tool at early design stages will benefit the design team through an improved understanding of the dynamics between facade design and building services and assist with a more integrated approach.     

The dynamics of alkalinity generation by an anoxic sediment exposed to acid water

The time dependence of the rate of generation of alkalinity by productive sediments treated with acid waters was investigated for various conditions using continuously stirred flowing reactors. Complete mass balances allowed the generated alkalinity to be related to specific processes, none of which were affected by light. The high rate of oxidation of organic material was sufficient to consume all the oxygen, nitrate and sulphate supplied to the vessels during the first few days of incubation, but by 15 days sulphate reduction had ceased and oxygen and nitrate reduction were incomplete. In incubations supplied with anoxic waters there was an initial small release of calcium, but by 10–15 days the generation of alkalinity could be accounted for by nitrate reduction (23%), sulphate reduction (47%), Fe(II) production (23%) and NH₄⁺ production (7%). Iron(II) was exhausted when only 1% of the total amount of iron in the sediment had been released. In incubations supplied with oxygenated waters sulphate was only reduced during the first 10 days while oxygen was completely consumed. By 15 days there was incomplete consumption of oxygen and the generation of alkalinity was accounted for by nitrate reduction (36%), calcium release (53%) and NH₄⁺ production (11%). Comparisons of reaction rates indicate that calcium is released by being replaced by ammonium ions which are generated by decomposition of organic matter. Although, in the longer term, more base is generated by sediment incubated anoxically, sediments incubated with oxygenated water generate base more rapidly for the first few days until the most readily oxidized organic matter is consumed.     

儿童友好型社区营造中的参与者社会网络构建与分析 —以湖南省长沙市育才第三小学"娃娃农园"营造实践为例

Introducing the case of the Kids’ Gardens in Yucai No. 3 Primary School in Changsha City, Hunan Province, this study established sociograms upon the contact-frequency-based network with UCINET to systematically analyze the characteristics of different participants in the process of the childfriendly community building and the varying pattern of all social relations, aiming at addressing problems emerging in public participation and multi-stakeholder collaboration in Chinese mainland. It was found that by bonding stakeholders including citizens, the government and party organizations, universities, and public institutions and enterprises, this practice encouraged the school — as a community — to leverage its internal resources. The school finally overcame the organizational inertia and achieved independent operation and growth during the process of community building. The study also demonstrated that the social network of participants was developed and defined with both independent and dependent modes from an overall perspective, of which the former characterized for its dominant internal ties and a dense tree-like hierarchical management structure might be more efficient. From a participant perspective, the brokerage roles in key nodes were critical to the community building. Finally, spatial design strategies, including enhancing the spatial affordance to serve diverse activities, space zoning and allocation, offering “half-done” spaces, and phased development, were provided for similar community building practice.     

Architecture a sspatial-textile storytelling: Metamorphosis of frieze as a narrative medium mediating the Panathenaia festival

Classical temples constructed by an entire class are considered as a democratic artifact that symbolizes social and communal beliefs and embodies religious significance. In contrast with these meanings that existing scholars have addressed, this paper investigates the extent to which architecture, as both shelter and artwork, serve as a medium of spatial-textile storytelling, providing a rich sensory context that represents and mediates culture. This study is drawn from a case study of the Ionic frieze in Parthenon, Athens, considered both a textile and spatial storytelling device. The research method applied in this paper consists of a literature review of references on the ideas on the links between textile making and architectural ornament by Gottfried Semper, as well as the historical development of the frieze in both textile weaving and classical architecture. The paper concludes that the significance of the religious Panathenaia festival is not merely depicted by the peplos identified on the central east Ionic frieze, but is also expressed in the entire representational scheme of the Ionic frieze, along with the overall spatial configuration of the Parthenon. Architecture, instantiated by the Parthenon, is regarded as spatial-textile storytelling to communicat emeanings.     

Screens

The screen is a recurring element in the work of Niall McLaughlin Architects . Environmental considerations have provided the opportunity for inclusion of the screen in built works, but it has been embraced by them for its geometric and material qualities, as well as the play it affords with light. The practice has relished the transformative powers of inserting everyday found objects into the screens to provide an additional level of surprise and delight. Copyright © 2008 John Wiley & Sons, Ltd.