对《公路钢筋混凝土及预应力混凝土桥涵设计规范》（JTJ 023－85）和（JTGD62－2004）《铁路桥涵钢筋混凝土及预应力混凝土桥涵设计规范》99年版和2005年版、ASSHTO－1994规范中在相同条件下，通过不同的加载龄期、不同的环境相对湿度等其中一个参数变化时对各规范收缩应变、徐变系数进行分析和比较。主要结论为：混凝土收缩应变主要与环境的相对湿度有关；混凝土的徐变系数，各规范相差较大，铁路规范中徐变系数仅与加载龄期有关，与混凝土的所处相对湿度无关，且其徐变系数相差不大；公路规范中加载龄期及湿度均对其有影响，但湿度对混凝土徐变系数影响更为敏感；在设计和施工中尤其是混凝土前期养护时的湿度应重点关注。综合分析表明，JTGD62－2004考虑参数较多、较为合理，建议铁路规范进行适当调整。

Taking one parameter variation between different loading time and different environmental relative humidity which are coming from reinforced and pre-stressed cement concrete design of high-way bridge (JTJ 023-85 )and (JTG D62-2004),pre-stressed and reinforced cement concrete design of railway bridge published in 1999 and 2005,AASHTO 1994 into consideration,shrinkage strain and creep coefficient of cement concrete according to different design specification are analyzed and com-pared.Some conclusions can be gained as follows:shrinkage strain of cement concrete is mainly asso-ciated with the relative humidity of environment;creep coefficient of cement concrete changes greatly according to different designing specification,creep coefficient of cement concrete which is only related to loading time and not relevant to relative humidity has a little change in railway specification;but creep coefficient is sensitive to humidity which is influenced by loading time and humidity in hig

在乌兹别克斯坦的海外工程中,需要参考或使用乌兹别克斯坦相关混凝土规范,鉴于中乌两国规范之间存在差异,为了有助于理解乌兹别克斯坦规范中对混凝土的配制强度及强度等级等概念的规定,先从数理上对混凝土强度等级及配制强度的关系进行推导,然后介绍了两国规范对此的相关规定,进行横向对比,并着重对乌兹别克斯坦规范混凝土强度等级及配制强度的关系进行了解析。乌兹别克斯坦认为:乌兹别克斯坦混凝土标准对配制强度的规定本质上也是基于随机变量的正态分布,要求对混凝土强度等级应具有足够的保证率;混凝土配制强度与混凝土强度等级之间的计算公式在形式上与我国不同,但可以通过变换化为一致,其本质是一样的;指出乌兹别克斯坦相关机构对2个概念的理解和执行情况与我国有不同之处,需要引起注意。

During the construction of the overseas projects in Uzbekistan,relevant Uzbekistan concrete codes need to be referred to.However,there is some difference between Uzbekistan concrete codes and Chinese concrete codes.In the paper,the correlation between the concrete strength grade and the concrete preparation strength specified in Uzbekistan concrete codes is deduced mathematically,the regulations on the concrete strength grade and the concrete preparation strength specified in Uzbekistan concrete codes and those specified in Chinese concrete codes are presented and compared,and the correlation between the concrete strength grade and the concrete preparation strength are analyzed. Conclusions drawn are as follows:The specifications on the concrete preparation strength in Uzbekistan concrete codes are actually normal distribution based on random variables,which requires adequate guarantee rate for the concrete strength grade;The form of the conversion formula between the concrete preparat

文章分别采用DL/T5057-2009《水工混凝土结构设计规范》和ACI318-2008《美国混凝土房屋建筑结构规范》对水电站吊车梁结构进行了承载力极限状态及正常使用状态两方面的分析,阐述了中美混凝土结构设计规范的差异和相同之处。对于吊车竖向荷载美国规范分项系数值较中国规范大。吊车梁在相同设计弯矩下,抗弯钢筋面积中美规范基本一样;相同剪力下,抗剪箍筋美国规范较中国规范大27%左右;考虑剪扭作用的箍筋和抗扭纵筋面积,美国规范较中国规范大13%左右。

The paper discusses the differences and similarities between DL/T5057-2009"Design Code for Hydraulic Concrete Structures" (Chinese code) and ACI318-2008"Building Code Requirements for Structural Concrete and Commentary"(American code) through analysis on bearing capacity of hydro-powerhouse crane girder under both ul-timate limit state and servicing limit state. For vertical loads on the crane, the partial coefficient of American code is greater than Chinese code. Under the same designed bending moments, the bending rebar areas of the crane girder are nearly the same in both American code and Chinese code;under the same shear strength, the shear stirrups of Ameri-can code is about 27%greater than Chinese code;under the actions of shear and torsion, the areas of both stirrups and longitudinal bar of American code are about 13%greater than Chinese code.

传统的水泥混凝土养护方式不规范、不科学,往往因养护不当导致强度不足与产生温度裂缝。水泥混凝土智能养护系统采用先进的控制技术,通过温度、湿度、水化热多参数自动分析控制混凝土的养护施工,可保证养护过程规范、科学、精细,对提高混凝土强度、减少裂缝的出现、提高养护效率意义重大。

The traditional way of cement concrete curing is not standardized,scientific,Often due to improper maintenance lead to insufficient strength and temperature cracks generated.Concrete curing system uses advanced intelligent control technology,Through the temperature,humidity,heat of hydra-tion analysis of multi-parameter automatic control of concrete conservation construction,to ensure the conservation process standardized,scientific,fine,to improve the strength of concrete and reduce the ap-pearance of cracks and improve the efficiency of conservation significance.

冬季是混凝土施工的重点与难点。针对混凝土工程在冬季施工的具体特点，本文介绍了几种常用的施工方法，并依照混凝土冬季施工的具体规范，对混凝土工程冬季施工的准备工作和质量管理进行了系统地论述。

Concrete construction is difficult in winter but it is real y important. According to the specific characteristics of concrete engineering in winter, this paper introduces some co-mmon construction methods, and in accordance with the deta-iled specification of concrete construction in winter, systemati-cal y discussed the preparation and quality management of co-nstruction of concrete engineering in winter.