共查询到20条相似文献，搜索用时 62 毫秒
1.
陈宇 《石家庄铁路职业技术学院学报》2018,(1)
针对隧道工程特点及二衬混凝土目前施工存在质量问题,详细分析了隧道二衬采用高性能自密实混凝土优势和必要性,从自密实混凝土的技术特点和配制技术途径来看,该材料及技术可以很好解决隧道二衬混凝土施工技术难题,并能极大提升二衬混凝土的耐久性和抗渗性,自密实混凝土在隧道工程中具有广阔的应用前景。 相似文献
2.
为满足修补混凝土自密实的要求,利用高效复合减水剂增塑和超细复合粉煤灰改善胶凝材料级配等有效措施,尽可能降低新拌混凝土屈服剪应力,使混凝土拌合物达到自密实所需要的流动性,在大量试验的基础上确定了自密实混凝土的配比参数．针对超早强的性能要求,通过胶砂试验,在多种化学外加剂中,选取早强剂A作为超早强水泥混凝土的外加剂,并确定其合理的掺量,同时在此基础上对自密实超早强高性能混凝土的配制技术进行优化,试验结果表明:选用高效减水剂、早强剂A、普通硅酸盐水泥可配制出1d的抗折强度达3．0 MPa以上,2d抗折强度达4．0MPa以上,自密实性能好,30min后混凝土拌合物坍落度损失小的自密实超早强高性能混凝土,能够满足对混凝土路面进行快速修补、无需振捣的要求． 相似文献
3.
通过在河北地区低强度等级自密实高性能混凝土的试验研究,得出自密实高性能混凝土的工作性能规律,研制出低强度等级的免振捣自密实高性能混凝土,促进自密实高性能混凝土在我国的推广应用. 相似文献
4.
5.
何文敏 《石家庄铁路工程职业技术学院学报》2011,(3):29-32
介绍北深沟大桥钢管拱混凝土灌注施工工艺、方法和技术要点,并介绍该桥自密实微膨胀高性能钢管混凝土配制的设计思路、技术要求。 相似文献
6.
自密实混凝土作为一种具有高流动性、不离析、不泌水、均匀性和稳定性,浇筑时依靠其自重流平并充满模板和包裹钢筋,无需振捣便能均匀密实成型的新型高性能混凝土,在越来越多的工程领域被运用.本文着点阐述自密实混凝土高性能特点,对自密实混凝土在类似水利工程建设中的应用有一定参考作用. 相似文献
7.
8.
新型混凝土材料在土木工程领域中的应用 总被引：2，自引：0，他引：2
张鹏 《邢台职业技术学院学报》2008,25(1):46-49
本文对高性能混凝土、活性微粉混凝土、低强混凝土、钢纤维混凝土、自密实混凝土、智能混凝土等的性能进行了总结,并对其应用与发展作了简要的介绍与分析。 相似文献
9.
10.
宇文利 《石家庄职业技术学院学报》2007,19(2):58-60
简要论述了新型混凝土(高性能混凝土、活性微粉混凝土、低强混凝土、轻质混凝土、钢纤维混凝土、自密实混凝土、智能混凝土等)及混凝土增强材料(非金属配筋、新型预应力钢棒等)的材料组成,以及新型混凝土近年来在工程中的应用与发展. 相似文献
11.
12.
13.
《海外英语》2007,(5):10-11
Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help? 相似文献
14.
邱崇丙 《唐山师范学院学报》2014,(1):21-23
汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。 相似文献
15.
《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love. 相似文献
16.
Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject. 相似文献
17.
Rachel Zupek 《海外英语》2007,(11):40-41
我们绝大部分人都同意一件事情——我们喜欢金钱。但是你对金钱的喜欢之情足够到让你创立一份事业么?.财富通常被人忽视,主要在于人们不能真正了 相似文献
18.
Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities. 相似文献
19.
20.
RUZBEHANI Mohsen 《重庆大学学报(英文版)》2004,3(1):20-25
1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec… 相似文献