高温气候环境下混凝土温度施工控制

沙特利雅德大桥施工处于高温、炎热、干燥气候条件中,按照AC I305R规范要求,应对混凝土拌和物的温度进行控制,一般采取加冰冷却工艺。介绍了加冰混凝土的温度计算和施工控制措施。     

高强混凝土技术及其应用

近年来,高强混凝土得到人们的普遍关注。高强混凝土技术是通过掺入高效减水剂和优质掺和料采用普通设备和常规的生产工艺,生产出强度等级更高、施工性能更佳、综合技术经济效益更好的混凝土。着重介绍高强混凝土的高强机理、基本组成材料、配合比设计与施工工艺等有关问题,阐述其技术要点与应用前景。     

浅析监理对简支梁钢筋混凝土施工的质量控制

通过对简支梁钢筋混凝土工程施工过程中的模板、钢筋、混凝土的事先控制,从而提高施工质量,避免质量问题的出现。     

Controls on stratification in the Rhine ROFI system

Stratification in the Rhine ROFI is very variable; the mean water column stability is controlled by the combined effect of tidal, wind and wave stirring which, at times, brings about complete vertical homogeneity. Control by the mixing variables has been elucidated by a regression analysis of mean stratification on the components of the windstress and significant wave height. There is strong partial correlation with all three variables which explains between 56% and 65% of the variance in two time series of observations in October 1990 and September 1992, respectively. During periods of low stirring the water column was observed to re-stratify over the whole inshore region through the relaxation of the horizontal gradients under gravity and with the influence of rotation. Superimposed on the mean stratification there is strong semi-diurnal variation, occurring throughout the stratified region at times of reduced mixing. The amplitude of this semi-diurnal variation is of the same order as the mean stability and frequently results in conditions being mixed or nearly mixed once per tide. This semi-diurnal variation results primarily from cross-shore tidal straining which interacts with the main density gradient to induce stratification. The hypothesis that water column stability is controlled by the combination of these processes has been tested using a reduced physics model which has been successful in reproducing the main features of both the mean and semi-diurnal components of stratification.     

影响混凝土强度的几个问题

分析水泥、集料、施工工艺等对混凝土的影响,以便于 混凝土施工过程及原材的控制。     

深层水泥搅拌法在淤泥质软弱地基加固中的应用

对连云港地质条件下采用的软淤加固技术手段进行了分析、比较,并通过试验建立了深搅法用于地基加固的工程质量控制及评定标准,以进一步拓宽深搅法在港口工程的应用,探索适应软淤地质的更合理有效的加固手段。     

浅谈沥青混凝土路面施工监理

该文以沥青混凝土施工的重要环节,相关的施工管理、监督工作和相关技术指标、质量标准作为重点,根据工程质量的要求,以及工程的实践经验,进行了总结和探讨,可供同行参考。     

大面积堆场施工“水泥稳定砂砾层”质量控制措施

通过原材料质量控制、配合比设计、恰当的拌合、正确的压实工艺和养生,水泥稳定砂砾基层满足了设计和使用要求。     

客运专线无砟轨道路基面防水型沥青混合料指标体系与配制技术

在分析无砟轨道路基面防水层功能要求和沥青混合料水力行为的基础上,提出适合客运专线无砟轨道技术要求的路基面防水型沥青混合料SAMI(surface asphalt mixture impermeable)的指标体系。通过大量的马歇尔试验,研究影响SAMI混合料渗透性能的因素如空隙率、沥青含量、级配组成和最大公称粒径,提出路基面防水性沥青混合料的建议技术标准。试验表明,SAMI-10可以作为客运专线无砟轨道路基面防水层的主型设计方案。提出路基面防水型沥青混合料应考虑温度分区,在进行SAMI混合料设计时,应以渗透系数和空隙率作为控制指标,以马歇尔稳定度、冻融劈裂强度比和低温收缩系数作为优化指标。并以SAMI-10为例,给出路基面防水型沥青混合料的配制技术。     

沥青混凝土拌和设备施工控制技术

在我国，用于路面施工的强制间歇式沥青混合料拌和设备已经取代了传统的滚筒连续式拌和机，在施工中占有主导地位，笔者从配合比精度控制、成品料温度控制、溢料控制和关键部位的控制这几个要点，论述沥青混合料拌和设备施工控制技术。