探究高层建筑施工技术要点

高层建筑施工是一项复杂的系统性施工工程,不仅施工难度大,而且施工的要求较高。这对于施工技术也提出了较高的要求。施工过程中需要根据实际施工情况把握施工技术要点,做好施工技术检查工作,确保施工技术规范性和合理性。同时,施工单位需要认真了解施工特征以及施工环境的现状,方便对高层建筑施工技术做出科学的分析。包括对基础施工技术、钢结构施工技术以及预制模板施工技术的把握,注意到这些施工技术中的关键施工点,有针对性地加强技术操作,从而增强高层建筑的施工安全管理,提高建筑的整体施工质量。     

水利工程冬季施工混凝土浇筑施工技术

我国的建筑工程在当下的经济环境下,取得了非常大的发展。建筑工程的施工进度一直在提升的过程中。在我国的建筑工程施工中,尤其是我国的北方,寒冷的冬天并不适合在冬季进行施工,因此在我国的建筑工程尤其是水利工程施工中尤其要重视冬季施工的施工进度以及施工质量。由于特殊天气环境的影响,我国的水利工程在冬季施工的过程中面临着非常的挑战,特别是水利工程的混凝土施工对于气温的要求格外的严格。因此水利工程的冬季施工在施工中要格外的重视施工的环境以及施工技术。混凝土施工在冬季施工中有很多的问题需要处理和解决,这样就为水利工程的混凝土施工带来了难题。因此我们要在混凝土冬季施工的过程中认真的分析施工的各项必要条件,保障混凝土施工在适当的施工环境下进行施工,有效的保障混凝土施工的施工质量。本文主要针对水利工程冬季施工混凝土浇筑的施工技术进行详细的分析和阐述,希望通过本文的阐述以及分析能够有效提升水利工程冬季施工中混凝土的施工质量以及施工进度,同时也为我国的水利工程施工的技术以及质量的进一步提升贡献力量。     

防爆场所电气施工要点分析

根据油田联合站、转油站等现场施工的实际情况,对电气施工中的防爆施工现状进行分析,找出施工中的薄弱环节,结合施工规范要求及现场施工经验,将其施工关键点进行总结归纳,解决施工中的不足,保证施工的顺利进行及运行安全。     

浅析水利工程冬季施工技术

冬季进行水利工程施工建设,工程质量受冬季自然环境的影响,容易导致工程质量下降,在施工实践当中为了有效规避冬季施工对水利工程施工质量所造成的不利影响,水利工程施工建设部门需要不断的加强水利工程冬季施工问题加强研究,充分运用各种施工技术,消除冬季施工的各种不利影响,确保我国水利工程施工的质量。     

现场施工技术在市政桥梁施工中的运用分析

该文主要从现场施工技术角度出发,阐述了钢箱梁安装施工技术在市政桥梁施工中的应用情况,并对其中涉及的施工要点进行说明。同时,针对性论述了现浇箱梁施工技术在市政桥梁施工中的应用,从基层施工、支架搭设施工、支架预压和模板安装施工以及钢筋预埋件施工要点和混凝土施工等不同角度进行分析,为现场施工技术在市政桥梁施工中的运用研究提供了参考。     

高层建筑大模板工程的施工

高层建筑主体结构施工,根据结构体系的不同,可采用以下几种施工形式:高层框架结构施工、大模板施工、滑升模板施工、筒体结构施工及台模施工工艺等。本文主要针对高层建筑工程中大模板工程的施工进行了详细的阐述,以期提高工程的施工质量。     

公路施工技术管理的重要性探讨

现代公路施工管理不仅仅是对施工材料、施工现场以及施工质量进行管理与控制,还需要通过对公路施工技术的管理工作保障施工过程工艺技术参数符合设计要求,保障公路施工质量。公路施工技术管理是现代公路施工管理工作的重点,其对公路施工质量有着重要的影响。文中就公路施工技术管理的重要性以及其对公路施工质量的影响等问题进行了简要论述。     

高压喷射灌浆施工技术在水利水电工程施工中的应用

在我国现阶段的水利水电工程施工过程中有很多的施工程序以及施工方式应用在个施工全过程中。在这些施工技术以及施工环节中,灌浆施工是非常重要的一个施工工序,同时灌浆施工所采用的施工技术也非常关键。经过我国现场工程施工多年的实践得出,在灌浆施工中采用高压喷射的施工方式对于工程灌浆施工来讲是非常有效的,能有效地保障工程的灌浆施工质量以及提升灌浆施工的工作效率。本文主要针对高压喷射灌浆施工技术在水利水电施工中的应用进行详细地分析以及阐述,希望通过本文的阐述以及分析能够有效地提升我国水利水电工程的灌浆施工质量,同时也为我国水利水电工程的进一步发展以及创新贡献力量。     

电力施工中输电线路的施工质量控制

输电线路施工作为电力施工中的核心内容之一。作为电力施工企业,要想在竞争日益激烈的市场中谋求生存和发展,就必须注重电力施工中输电线路的施工质量控制,才能更好地确保工程质量,最终提高企业的社会竞争力和市场适应力,基于此,笔者将本文命名为《电力施工中输电线路的施工质量控制》。分别从基础施工、杆塔施工、架线施工、光缆施工、检修施工等就电力施工中输电线路的施工质量控制措施进行了探究。旨在与同行进行业务交流,以不断提高电力线路施工质量。     

浅谈建筑施工项目管理工作

施工项目是建筑施工企业的生产对象,也是建筑企业的施工过程和最终产品。施工项目质量管理、施工项目进度管理、施工项目安全管理、施工项目成本管理要贯穿整个施工项目管理工作。     

Surface State Control by Ultrasonic Plastic Deformation at the Final Machining Stage

Basic results of research into the process of the surface geometry formation during ultrasonic plastic deformation of metallic materials are presented. The results of mathematical modeling of the microgeometry and surface undulation formation in the machining of materials of different hardness are also presented. Experimental validation of the adequacy of the proposed models is provided.     

Influence of surface roughness on the bonding quality in twin-roll cast clad strip

Manufacturing of aluminum-steel clad strips by means of twin-roll casting is of great interest due to a shorter production chain in comparison with convenient technologies. Experiments on twin-roll casting of clad strips of pure aluminum and an austenitic stainless steel of 2.5?mm total thickness with the inline abrasive cleaning of a steel substrate’s surface performed. The corresponding device for the inline surface preparation is designed. The influence of surface roughness of the substrate’s surface on the bonding strength between strip layers is analyzed. The mechanism of intermetallic bonding on the roughened surfaces is discussed. It is shown that surface roughness of steel substrate up to 4.2?µm provides bonding strength above 100?MPa.     

Einfluss der Werkstoffzähigkeit auf das Festigkeitsverhalten unter mehrachsiger Beanspruchung am Beispiel von Schweißverbindungen aus Stahl und Aluminium

Influence of Ductility on the Multiaxial Fatigue Behaviour by the Example of Welded Joints of Steel and Aluminium The multiaxial fatigue behaviour of materials with different ductility under constant and changing principal stress directions is also applicable to welded joints of different materials. For this, welded flange tube connections of the fine grained steel StE 460 and the artificially aged aluminium alloy AlSi1MgMn T6 were investigated under constant amplitude combined bending and torsion. Out‐of‐phase loading, i. e. changing principal stress directions, of the steel joints led to a decrease of fatigue life, which is observed at ductile material states. However, for the aluminium joints out‐of‐phase loading resulted same behaviour as in‐phase loading, which indicates a semi‐ductile material behaviour. The results for the welded steel joints were evaluated on basis of local stresses by the integral hypothesis of the Effective Equivalent Stress EES (WVS). This hypothesis for ductile material states takes into account the life decreasing influence of out‐of‐phase loading by considering the interaction of the shear stresses on different planes. The fatigue behaviour of the aluminium welds is described by the critical plane based combination of shear and normal stresses (KoNoS), which is valid for semi‐ductile material states.     

Certified reference materials of trace elements in water

Measurement of trace elements is playing a vital role in industries and various sectors of science and technology including semiconductors, food, health and environmental sectors. In most of the cases a small error in measurement can vitiate all the measures taken for quality control and management. Many decisions regarding the suitability of material/products are based on the analysis. To reduce or eliminate the rejection rate of the products, accurate and reliable measurements are needed which can be achieved by the use of certified reference materials (CRMs). Their use in calibration of analytical equipments and validation of test methods ensures high quality in measurements and it provides traceability to the measurement data with national/international measurement systems (SI unit) also. In the present scenario of globalization of economy, use of certified reference materials (CRMs) in measurements is essential for global acceptance of products and test reports. Their use fulfil a mandatory requirement of international quality systems (ISO 9000, ISO/IEC standard 17025) including our national accreditation body, National Accreditation Board for Testing and Calibration Laboratories (NABL), World Trade Organization (WTO) etc. International manufacturers of CRMs are meeting most of the requirement of CRMs of the country. To meet the demand of CRMs indigenously, the National Physical Laboratory, India initiated a national programme on preparation and dissemination of certified reference materials.     

Archaeometallurgical contributions to a better understanding of the past

Archaeometallurgical investigations, and in particular those employing metallographic techniques, have greatly increased our understanding of the past, primarily by improving our knowledge of the histories of technological developments. However, these studies have potential for contributing to our comprehension of many more aspects of life in the past. The series of case studies presented here illustrate the application of metallography not only in elucidating the history of technology but also in areas such as the dating of objects, the determination of the spread of technologies and the nature and implications of the contact of cultures with the ‘outside’ world.     

Central Venous Catheter Associated Infections Pathophysiology,Incidence, Clinical Diagnosis,and Prevention – A Review

The incidence of catheter related bloodstream infections poses a substantial burden on patient’s life’s and well‐being. Estimated 2 – 6 % of patients suffer from catheter associated bloodstream infections (BSI). Reports on mortality of these patients are up to 30 % in addition to a substantial prolongation of hospital days. The estimated cost of therapy of a BSI is approximately 10 000 € per patient. There is a definitive need for antimicrobially active medical devices for prophylaxis. Endowment of catheters with antibiotics and desinfectants have substantial limitations regarding spectrum of activity, duration of activity and clinical efficacy. The oligodynamic activity of silver has the greatest potential for prevention of catheter related infections. Various technologies in particular surface coating of these medical devices have been advocated previously with limited success. A new technology with impregnation of the entire catheter matrix with billions of nanoparticles of silver⁰ which results in a surface of 2000 cm²/g polyurethane (PU) has been developed. Central venous catheters manufactured according to the technology of the first and second generation have been investigated with good results of antimicrobial activity and biocompatibility. Favorable results in experimental investigations and good clinical results in controlled prospective, randomized, investigator blinded studies of the first generation silver catheter have been obtained. In 660 patients in an overall reduction of BSI of 66 % was observed. Favorable results in a postmarketing surveillance with 3000 patients were seen. The premarketing surveillance of the second generation silver‐catheter indicated an even greater reduction of catheter related BSI. In 204 patients with a mean duration of catheter placement of 9.2 days only one catheter related BSI was diagnosed. The rate of catheter colonization was <10 %. The catheter was well tolerated. A further improvement with increased antimicrobial activity was achieved by activation of silver nanoparticles in the third generation catheter: The superior results of in vitro tests and excellent biocompatibility lets us expect an additional improvement of preventive measures. The duration of antimicrobial activity has been investigated and lasts at least 370 days. The concept of impregnation of a polymer matrix and silicone can be extended to various other clinical applications e.g. Sheldon, Hickman and urologic catheters. Substantial savings in the cost of patient care through prevention of complications can be expected which is of particular importance with the disease oriented (DRG) remuneration system.     

Corrosion Resistance of an electrodeposited Zinc Coating Containing CeO2 Nanoparticles

A Zinc coating containing CeO2 nanoparticles has been deposited by electrodeposition in a zinc plating bath.The content of CeO2 in the coating is 0.22 mass%. The results of weight loss experiments and electrochemistry tests show that corrosion resistance of the Zinc coating containing CeO2 nanoparticles is remarkably improved in contrast to the pure zinc coating in 0.5 M MgSO4 solution. The effects of CeO2 microparticles on the corrosion resistance of the zinc coating have been studied, the results show that CeO2 microparticles have no effect on the corrosion resistance of the zinc coating. SEM and XRD experiments suggest that the presence of CeO2 nanoparticles in the coating causes the modification of the surface morphology and preferential orientation of the crystal planes; therefore, the reason for the enhancement of corrosion resistance is mainly related to improvement of the structure of the coating.     

Verbundstrangpressen von Titan‐Aluminium‐Verbindungen

Rod Extrusion of Titanium‐Aluminum Composites The combination of different metals enables the processing of materials with local optimized properties. Thus, the production of metallic composites is associated with high standards in manufacturing technologie. Focus of the following investigations is the rod extrusion process of titanium‐aluminum‐composites. Besides the mechanical properties, the formation of the bonding zone and the mechanisms of adhesion in the bonding zone were investigated. The influence of specimens’ preparation and of different coatings used improve bonding were a matter of particular interest. Whereas coatings of copper or nickel inhibit the formation of a strong bonding due to the formation of oxide layers, sealed titanium cores can reach a mechanical strength of up to 100 MPa after rod extrusion. Compared to other joining technologies, an impairment of the base metal via formation of heat affected zones, pores or grain coarsening does not occur.     

Experimental investigation on performance of additive mixed dielectric during micro-electric discharge drilling on 316L stainless steel

This study investigates the impact of machining factors on the performance of additive mixed micro-electric discharge drilling of 316L stainless steel. The effects of three kinds of powder, powder concentration, voltage, capacitance, feed rate, and speed on tool wear rate, material removal rate, taper angle, and overcut (OC) were also investigated. The experimental results show that adding additives to the dielectric enhanced rate of material removal and reduced rate of tool wear significantly. Mixing powder with dielectric increased the length of the sparking, resulting in significant OC, and process performance also improved with the increase in amount of powder added. Further, scanning electron microscopy analysis was carried out to examine the surface characteristics and material migration properties, which confirmed that the properties of the machined surface are indeed significantly improved.     

Energy and exergy analysis of single effect and series flow double effect water–lithium bromide absorption refrigeration systems

In this paper, the energy and exergy analysis of single effect and series flow double effect water–lithium bromide absorption systems is presented. A computational model has been developed for the parametric investigation of these systems. Newly developed computationally efficient property equations of water–lithium bromide solution have been used in the computer code. The analysis involves the determination of effects of generator, absorber and evaporator temperatures on the energetic and exergetic performance of these systems. The effects of pressure drop between evaporator and absorber, and effectiveness of heat exchangers are also investigated. The performance parameters computed are coefficient of performance, exergy destruction, efficiency defects and exergetic efficiency. The results indicate that coefficient of performance of the single effect system lies in range of 0.6–0.75 and the corresponding value of coefficient of performance for the series flow double effect system lies in the range of 1–1.28. The effect of parameters such as temperature difference between heat source and generator and evaporator and cold room have also been investigated. Irreversibility is highest in the absorber in both systems when compared to other system components.