【作者】 邓霞；

【导师】 严云； 陈军亮；

【作者基本信息】 西南科技大学 ， 材料工程（专业学位）， 2018， 硕士

【摘要】 随着高层建筑、超高层建筑的发展,大体积混凝土越来越多地出现在施工建设之中,并对工程质量起着重要作用。学者们对如何控制大体积混凝土的绝热温升以及温度裂缝开展了诸多研究,而从搅拌站角度出发系统地研究混凝土质量控制技术达到控制大体积混凝土绝热温升及温度裂缝的研究相对较少。本文以三个不同施工技术难度的大体积基础底板为例,从原材料选用、配合比设计、生产过程控制、施工及养护等方面,研究大体积混凝土施工的质量控制技术。津湾广场基础底板通过优选原材料,大掺量矿物掺合料以及采用缓凝型减水剂,历时52小时完成了浇筑任务。混凝土初凝时间26~28小时,终凝时间30~32小时;通过对大体积混凝土配合比绝热温升计算,以及委托第三方进行绝热温升测试,混凝土温升值未超过50~oC。周大福(Chow Tai Fook,以下缩写:CTF))金融中心基础底板在津湾广场基础底板的基础上,优化了骨料级配和空隙率,制定了更全面更细致的生产施工质量保障方案,历时38小时,比预期提前10小时完成了浇筑任务。大体积混凝土初凝时间24~26小时,终凝时间28~30小时,3小时经时坍落度损失基本为0;委托第三方测试绝热温升,未超过50 ~oC。中钢国际基础底板在大气温度-10 ~oC以下条件下施工,通过使用热水搅拌及相关保温措施保障混凝土入模温度不小于10 ~oC,历时45小时顺利完成25000 m3的浇筑任务。各基础底板均按照60天设计配合比、强度评定,经检验60天强度达到设计强度100%以上,满足设计要求。浇筑完成后,经查看混凝土表面均未见明显裂缝。更多还原

【Abstract】 With the development of High-rise buildings and super High-rise buildings,mass concrete is increasingly manufactured in constructing and engineering,which plays extremely important role in construction quality.Many researchers have carried out a lot of investigations on how to control the adiabatic temperature rising and the temperature cracks of mass concrete.However,systematic research on the quality control concerning the adiabatic temperature rise and cracks of the mass concrete is less from the point of view of concrete mixing station.This paper takes three base plates as example to study the quality control technique of mass concrete by selecting desirable raw materials,designing mix proportion and controlling production process,etc.The base plate of JinWan plaza had been placed and compacted within 52 hours by optimizing raw materials,adding large amount of mineral admixture and adopting retarding water reducer.The initial setting time of concrete was 26~28 hours and the final setting time was tested as 30~32 hours.By calculating the thermal insulation temperature of bulk concrete,a third party was entrusted to conduct adiabatic temperature rise test,the result showed the temperature rising of the concrete did not exceed 50 ~oC.On the basis of technical proposal of Jinwan plaza base plate,an optimized scheme which more comprehensive and detailed was applied to Chow Tai Fook(following abbreviation CTF)Financial Center to assured the construction quality by improving aggregate grading and void fraction.The base plate of CTF financial center has been completed within 38 hours,10 hours ahead of the schedule.The initial setting time of the concrete was 24~26 hours and the final setting time was tested as28~30 hours.The concrete slump loss was nearly 0 in 3 hours.The adiabatic rise of temperature was not exceed 50 ~oC which tested by the third party.The base plate of Sinosteel International Plaza was constructed under the condition of atmospheric temperature-10 ~oC,by using hot water and some thermal insulation measures to avoid heat loss,so as to guarantee the concrete temperature that casting into the slab was not less than 10 ~oC.The pouring task of 25000 cubic meters concrete was completed successfully within 45 hours.Each base plate was designed and assessed strength by the 60d,the strength of the concrete was tested and proved more than 100%of the design,meeting the design requirements.After poured,it was observed that there were no visible cracks on the concrete surface.更多还原