高性能混凝土自收缩的抑制措施

初步探讨了抑制高性能混凝土自收缩的措施。包括利用多孔骨料与多孔性矿物掺和料的自养护作用,粉煤灰的“能量滞后释放效应”、膨胀剂的补偿收缩作用,纤维的约束作用以及有机收缩低减剂的表面张力降低作用等,另外,早期养护也可有效地抑制早期自收缩。     

自动化制造系统中高性能计算模型的建立及应用

工业自动化系统不仅要对数据进行大量复杂的实时计算,而且这些自动化系统也必须是稳定可靠的,这在工业生产中是必不可少的。高性能计算为PC机群提供了各种概念的分布式算法。虽然高性能计算在科学研究中常见,但它很少在工业生产中应用,即使它能带来显着的计算性能的提高。由于这个原因,文章建立了分布和自我平衡机制的高性能通信模型,并将其具体应用到工业实践中。     

Device level communication libraries for high‐performance computing in Java

Since its release, the Java programming language has attracted considerable attention from the high‐performance computing (HPC) community because of its portability, high programming productivity, and built‐in multithreading and networking support. As a consequence, several initiatives have been taken to develop a high‐performance Java message‐passing library to program distributed memory architectures, such as clusters. The performance of Java message‐passing applications relies heavily on the communications performance. Thus, the design and implementation of low‐level communication devices that support message‐passing libraries is an important research issue in Java for HPC. MPJ Express is our Java message‐passing implementation for developing high‐performance parallel Java applications. Its public release currently contains three communication devices: the first one is built using the Java New Input/Output (NIO) package for the TCP/IP; the second one is specifically designed for the Myrinet Express library on Myrinet; and the third one supports thread‐based shared memory communications. Although these devices have been successfully deployed in many production environments, previous performance evaluations of MPJ Express suggest that the buffering layer, tightly coupled with these devices, incurs a certain degree of copying overhead, which represents one of the main performance penalties. This paper presents a more efficient Java message‐passing communications device, based on Java Input/Output sockets, that avoids this buffering overhead. Moreover, this device implements several strategies, both in the communication protocol and in the HPC hardware support, which optimizes Java message‐passing communications. In order to evaluate its benefits, this paper analyzes the performance of this device comparatively with other Java and native message‐passing libraries on various high‐speed networks, such as Gigabit Ethernet, Scalable Coherent Interface, Myrinet, and InfiniBand, as well as on a shared memory multicore scenario. The reported communication overhead reduction encourages the upcoming incorporation of this device in MPJ Express ( http://mpj‐express.org ). Copyright © 2011 John Wiley & Sons, Ltd.     

超塑化剂“CSP”对水泥水化及水泥石微观结构的影响

分别对掺与不掺超塑化剂“ＣＳＰ”的水泥试样进行测试分析，探讨了ＧＳＰ对水泥水化过程及水泥石微观结构的影响。传导量热法、结合水测定分析结果表明．ＣＳＰ使水泥水化的诱导期延长．对初期水化的抑制作用可延缓混凝土坍落度经时损失，而早期和后期水化加快，因此具有早强增器作用．ＴＧ—ＤＴＡ、ＸＲＤ、ＳＥＭ、ＭＩＰ等测试分析结果表明，ＣＳＰ使水泥石中凝胶农产物增多，有害孔减、无害孔增多，因而具有增强和提高混凝土耐久性的作用．     

高强免振C80～C100级高性能混凝土的试验研究

通过优选高性能减水剂,采用正交实验方法研究了浆体体积、水灰比、砂率对高强度混凝土工作性能及强度的影响,进而采用不同种类掺合料配置出C80～C100级免振高性能混凝土,经耐久性实验,表明该种混凝土可在实际工程中推广应用.     

供水管网中细菌再生长的直接和间接模拟

为了深入研究实际供水管网中细菌再生长的模拟,引入效率因子的概念,在简单反应器的基础上对可同化有机碳AOC的动力学进行了理论探讨,在几个假设条件的基础上,分别提出了实际管网中主体水和管壁反应的AOC动力学方程.现场取样测试结果表明AOC浓度随时间的变化符合提出的动力学方程（R2〉0.7）.根据AOC与异养菌平板计数HPC的相关性,通过模拟AOC的浓度变化间接模拟了HPC的分布;利用多物质反应模型直接模拟了管网中的细菌变化,并通过算例验证了两种模拟方法的可行性.     

矿粉与粉煤灰双掺在高性能混凝土配制中的应用

文章通过具体试验研究了单掺粉煤灰、双掺粉煤灰和矿粉条件下,混凝土强度及抗氯离子渗透性,其结果表明粉煤灰和矿粉双掺可以很好的配制出高性能混凝土。     

高性能混凝土早期开裂防治措施研究

早期开裂是当前混凝土施工应用中经常出现的质量通病,采取什么样的措施防止这种开裂成为当前研究热点.就掺入聚丙烯纤维、碳纤维、减缩剂及复合使用时混凝土的早期开裂、自收缩、抗渗性等进行了试验研究,并从扫描电镜照片进行微观结构分析.结果表明:纤维或减缩剂的加入都对混凝土早期开裂有一定抑制作用,但对混凝土抗压强度有一定降低.从综合性能看,各种措施对防止混凝土早期开裂的效果优劣次序为:减缩剂>减缩剂+聚丙烯纤维>碳纤维>聚丙烯纤维.     

高性能混凝土耐久性的探讨

混凝土高性能化是未来混凝土发展的方向,而耐久性是高性能混凝土重要的性能,本文从混凝土的渗透性、抗硫酸盐侵蚀、抗冻性、碳化等方面综述了高性能混凝土的耐久性,并探讨了提高高性能混凝土耐久性的措施.     

高性能混凝土配合比智能化系统研究进展

介绍了高性能混凝土配合比设计及其智能化在国内外的研究进展,分析了高性能混凝土配合比设计存在的问题,指出了需要进一步深入研究的方向,为高性能混凝土配合比的研究与工程应用提供了参考.