谈高强混凝土与高性能混凝土之异同

随着时代的进步和建筑材料科学技术的发展，作为主要建筑材料之一的混凝土材料得到了极大的发展，应运而生了高强混凝土和高性能混凝土。而高性能混凝土更是被国内外专家学者称之为21世纪混凝土，受到了学术和工程界的极大关注。而在高性能混凝土的研究应用过程中，国内尚存在将高强混凝土和高性能混凝土等同认识的现象。本文以高强度和耐久性为出发点就高强混凝土和高性能混凝土的关系做一分析。     

智能混凝土的研究现状及其发展趋势

智能混凝土是现代建筑材料与现代科技相结合的产物,是传统混凝土材料发展的高级阶段。回顾智能混凝土的发展历史和研究现状,并展望智能混凝土的发展趋势和应用前景。     

高强度混凝土与高性能混凝土

1 高强化与高性能化是当代混凝土科学发展的必然趋势 混凝土是一种应用十分广泛的人造建筑材料,推广应用至今已有一百多年的历史。在人类建设事业中发挥了巨大的作用。由于混凝土具有可塑性,大部分原材料可就地取材。消耗能源较少,今后仍将是一种主要的建筑材料。近年来混凝土技术还将继续发展,高强度混凝土与高性能混凝土是其主要发展方向,它将成为跨世纪的建筑材料。     

高强高性能混凝土在我省的工程应用

混历上是现代土木建筑工程中最重要也是最大宗的建筑材料，高强与高性能则是混凝土技术的一个重要发展方向。高强检的重要特点就是强度高、变形小、耐久好，能适应现代工程结构向大跨、重禁、高耸发展和承受恶劣条件的需要。而高性能破不仅要束检要达到高强，而且g有高的流动性     

C80高强粉煤灰混凝土及其应用

本文研究了粉煤灰等量替代硅酸盐水泥利用压蒸工艺配制Ｃ８０高强混凝土，试配结果表明，利用粉煤灰在压蒸工艺条件下可等量取代３５％的５２５Ｒ硅酸盐水泥产Ｃ８０混凝土，同时可降低２３％的高效减小剂的掺量，管桩试生产结果表明，可大大减少水泥掺量，降低生产成本，取得很好的经济效益和社会效益。     

西北地区高性能混凝土在超高层建筑中的应用

近年来,我国超高层建筑发展迅速,在西北地区也越来越多,而且大多都采用了高性能混凝土,本文分析探讨了西北地区高性能混凝土在超高层建筑中的应用。     

石屑混凝土商品化试验研究

通过优选高效减水剂和配合比,改善石屑代砂混凝土需水量大和坍落度经时损失大的缺点,使其适应商品化 生产,并对石屑代砂混凝土的力学性能、抗渗性能及收缩进行了测试,证明石屑代砂应用于商品混凝土是可行的。     

改性混凝土综述

本文从混凝土的演变过程及改性混凝土的优点论述了研究和发展改性混凝土的必要性及实现混凝土改性的常用方法 ,在文章的最后简要介绍了我国混凝土改性方面的发展及应用     

Untersuchungen zur Genauigkeit von magnetisch induktiven Betondeckungsmessungen

Assessment of the accuracy of concrete cover measurements using Eddy Current devices The use of non‐destructive testing in civil‐engineering (NDT‐CE) is well established to assess as‐built drawings for existing structures as well as for quality assurance of new buildings or in case of concrete repair. To gain reliable results the choice of the appropriate testing method in combination with the correct data assessment is essential. Hence this article starts with the basics of the two typical testing methods for concrete cover measurement with high precision. Methods based on Eddy Current and based on Radar are different. The strengths and limitations of both methods are presented. In the second part the achievable accuracy of concrete cover measurements using Eddy Current will be assessed for the most important parameters that have been varied in a wide range. It is shown how results are influenced by an improper input of the diameter or by the effect of neighbored rebars. At the end of the article it is shown how the deviation of the results can be minimized using the internal neighboring rebar correction of some of the devices. This article does not intend to be a product test rather the influence parameters of measurements close to reality will be identified and quantified how the accuracy of concrete cover measurements is affected.     

The dilution of waste in the wake of a ship

This paper considers the problem of predicting the dilution of waste which has been discharged into the wake of a moving ship. A theoretical model is developed which relates the dispersion of the effluent field to the intensity of the turbulence created by the movement of the vessel. Specifically, the model describes the dependence of the dilution on the speed, dimensions and specific resistance coefficient of the ship.The new theory predicts that the rate of dilution decreases with time after discharge and, as with the empirical IMCO formula, indicates that dilution is more sensitive to the speed of the ship than the volume rate of discharge of waste.     

Zustandsuntersuchung und Instandsetzung am Hauptdach des Hauses der Kulturen der Welt in Berlin

The main roof of the ”Haus der Kulturen der Welt“ in Berlin Which is very well‐known on account of its history and striking structural design – was to be inspected by the author to determine its condition and analysed with regard to the durability of the existing liquid synthetic sealant. The roof structure consists of a biaxial, curved area‐covering structural element with circumferential edge beams of pre‐stressed lightweight concrete. This is the result of the reconstruction between 1984 and 1987 following a partial collapse of the then Berlin Congress Hall in 1980. The very thin roof shell is also made of lightweight concrete and, like the edge beams, has a polyurethane‐based spray‐on seal that was specially developed for this purpose as protection against the ingress of moisture. The reason why this, at the time, novel type of seal was chosen was that it should take into account the fact that the roof design urgently needed some kind of protection against moisture that had to compensate the expected changes shape and crack movements of the roof with no damage. The following article reports on the nature, scope and main results of the analysis of the condition of the roof seal, edge beams and abutments. It will also describe the repair recommendations resulting from the investigations, which form the basis of the execution of work at the present point in time. Apart from presenting the technical principles and special features of the building that have to be taken into account during any repairs, the special features of the execution will also be addressed.     

Magnetoelastische Spannkraftmessung in Bauwerken

Magnetoelastic Measurement of Prestressing Force in Civil Structures The knowledge of the tensile force of prestressing steel elements and its reliable and non‐destructive determination are of essential importance for the assessment of the structural health condition of prestressed concrete structures and tie‐back systems in terms of structural safety, serviceability and durability. For the evaluation of the prestressing force in steel tension members, the measurement technique presented in this contribution is using the magneto‐elastic effect (ME‐effect) of ferromagnetic materials. This effect describes the reverse‐proportional correlation between the mechanical stress and the magnetic properties of ferromagnetic materials. The cylindrical coiled sensors pushed over the tendon and the measuring device developed and practically optimized at the iBMB/MPA of the TU Braunschweig enable a fast and reliable measurement of the prestressing steel force after an initial calibration. In this contribution first the state of the art of prestress measurement techniques for steel tension members is presented. Afterwards, the ME‐measuring method with the basics and merits of magneto‐elastic prestressing force identification is shown. Further recent research results as well as several building applications will be discussed.     

Untersuchungen der Auswirkungen eines Vollbrands auf eine Sporthalle

Research of Fire Effects on a Gymnasium An arson attack committed in August 2015 on the gymnasium of the Oberstufenzentrum Nauen school facility built in 2007 led to a full fire and to the complete destruction of the hall. The effects of this fire were recorded with measuring technologies as well as through sampling on‐site. In the course of this, the wooden roof structure was particularly examined and demonstrated a residual load‐bearing capacity in spite of the intensive fire exposure and the resulting significant damage. The remaining support structure of the hall was completely recorded by means of Terrestrial Laser Scanning (TLS) and evaluated in September 2015. Inclinations, cross‐sectional shifts and deformations in the building were able to be calculated with the geodetic measurement method. The results from the laser scanning in combination with the sampling served as a comparison of the theoretical structural evidence with the effects of an actual fire event. In the case of the fire at the Nauen gymnasium, the damage to the load‐bearing capacity was particularly significant in the area of the joining means. The goal of the investigations is a comparison of the technical engineering fire prevention certifications and their theoretical protective effects with the effects of actual fires. This is also a subject of current research projects in the Beuth Hochschule für Technik Berlin, University of Applied Sciences.     

对“建筑”内涵的重新审视与诠释

“建筑”现行内涵的功利与暧昧,是当代建筑粗糙、乏味的主要根源之一.为解决这一问题,首先分析了“architecture”、“营造”与“建筑”三者的内涵.通过将“建筑”与“architecture”及“营造”分别比较,审视了“建筑”的现行内涵;并对其内涵提出了新诠释.     

基于HSS模型隧道近接群桩基础施工影响分析

依托盾构隧道近接侧穿群桩工程建立三维数值分析模型,土体采用小应变硬化(HSS)模型,参数取值借鉴已有研究成果并根据监测位移数据反演,同时考虑土体开挖、衬砌拼装以及盾尾同步注浆等一系列施工工艺措施,并将模拟结果与监测数据进行对比验证,研究了不同工况下地表沉降的形态分布、群桩桩基变形及基桩结构受力,同时考虑地表位移对等代层厚度的敏感性。结果表明:HSS模型能有效预测隧道近接侧穿高架桥桩引起的变形,模拟结果与监测值较吻合; 隧道开挖引起土相对桩产生了滑移,地表沉降及桩身竖向位移在中心线前后各1D(D为管片外径)范围内随推进步数的增加而不断增大,且增加幅度明显减小; 两线推进地表沉降具有叠加效应,最大沉降量增幅达76.8%; 隧道与基桩水平距离越近,引起基桩沉降变化越大,两线推进基桩桩顶沉降增幅达134%; 群桩中各排桩的水平位移变化趋势基本相同,且同排桩的水平位移值相差不大,由于群桩遮挡效应,水平位移值由大到小依次为前排桩、中排桩、后排桩; 桩身水平位移主要在盾构中轴线2.5D范围内,桩身最大水平位移均出现在隧道中轴线附近; 群桩中同排桩桩身附加弯矩及附加轴力沿桩身分布规律相同,桩身最终附加受力与其距离隧道远近有关; 随着注浆充率β的增大,等代层厚度及地表沉降呈线性减小; 穿越段采取的施工工艺方案是有效的,经估算附加弯矩及轴力对桩基承载力的影响在容许范围内。     

采空区隧道二衬受力特性模型试验与耦合分析

由于采空区地层的非连续特征,下穿隧道衬砌往往处在偏心受压的不利状态,后期运营病害相对严重。为了查清不同采空区条件下的衬砌结构受力特性,采用室内物理模型试验和基于连续-非连续耦合数值模拟相结合的方法,开展了相关研究。结果表明:(1)采空区的存在会使二衬结构受到偏压荷载,远离采空区侧总体受力大于近侧,且倾角越大偏压越严重;(2)采煤层厚度、冒落带与初支距离的增大会引起围岩压力的降低,二衬内力减小,安全性提升,当采煤层厚度大于1.8 m时或冒落带与初支间距大于0.8倍隧道洞跨后,采空区对二衬安全性的影响很小;(3)喷层厚度的增加阻碍了围岩变形,引起围岩压力增加,不利于二衬受力和安全性。研究结论对于完善采空区隧道围岩压力计算理论和支护结构设计方法具有理论指导意义。     

城市物质空间结构中的面元素

基于建筑师立场,对大尺度的城市物质空间的诠释和操作提出分类。主要提出镶嵌状的面．元素层叠形成的面．地块-街区-街道形成的面三种面元素。面元素与点元素和线元素的主要区别在于．城市中的面自身占据较大尺度的空间面积,而点和线元素则是局部的空间构成要素。结合具体案例深入解析三种面的诠释视角对设计操作的影响。在结论中点明了提出“点-线-面”诠释和操作城市物质空间的意义。     

论电梯的安全、质量与标准

论述了电梯的特殊性、电梯安全的重要性;分析了政府主管部门、公众和媒体对电梯事故（故障）高度关注的原因;讨论了电梯安全与故障、可靠性的关系,电梯安全标准与安全、质量、运行性能的关系,以及电梯现行标准的性质;界定了安全标准与设计、制造规范的不同及关系;分析了行业及政府主管部门对公众普及电梯知识,客观、冷静地看待电梯故障与安全的重要性;说明了业内专业人员和政府主管部门应引导媒体和公众正确看待作为新型机电运输设备的电梯,认识不同档次电梯产品其质量和可靠性不同的必然性。