大体积混凝土采用普通硅酸盐水泥的施工措施

金辉大厦位于广东省湛江市人民大道南,由主楼ｕ区）、副楼侣区）和前庭人防地下室（Ｃ区）组成,主楼４４层,高１５０．１０ｍ;副楼２８层,高９６．６０ｍ,总建筑面积１３．１３８万ｍ２（见图１）。底板标高－８．４０ｍ,厚２．５ｍ,采用梁板式混凝土筏形基础,混凝土强度等级为Ｃ３５,抗渗等级Ｓ８,混凝土用量为１１７０５ｍ３,主楼底板采用５２５＃普通硅酸盐水泥。本文介绍主楼大体积混凝土的施工情况。主楼底板混凝土用量约为７８００ｍ３。一般情况下,大体积混凝土宜使用水化热低的矿渣水泥或火山灰质水泥。受水泥供货条件…     

缓凝型泵送剂在大体积混凝土中的应用

缓凝型泵送剂在大体积混凝土中的应用武海蔚王会彦王文彬黄慰成赵士举１工程概况石家庄第二长途电信枢纽主楼高２０３ｍ，筒体框架结构，基础底板混凝土设计为Ｃ４０、Ｓ８，板厚２ｍ，表面系数１．１，混凝土总量４１００ｍ３。２原材料及混凝土配合比缓凝泵送混凝土（以...     

山西国际贸易中心工程大体积混凝土施工

山西国际贸易中心位于太原市府西街与三桥街交会处,建筑面积１８４０００ｍ２,地下２层,地上由２栋４０层主塔楼、１栋１９层商住楼和５层裙房组成。本工程大体积混凝土底板共３块,分别为东、西主塔楼、商住楼基础底板,厚度分别为２．８ｍ、２．８ｍ、１．４ｍ（图１）,混凝土总量１１５００ｍ３,钢筋总量２１００ｔ。板下均为钢筋混凝土灌注桩桩基。１大体积混凝土底板的施工条件本工程大体积混凝土底板于６月底至７月底期间施工,需选择在无雨日进行混凝土浇筑。根据当地气象预报,每块底板浇筑时间不允许超过４８ｈ。底板浇筑时日…     

利用混凝土松弛特性控制3.5 m厚大体积混凝土裂缝的措施

厦门邮电大厦塔楼高３４４．２１ｍ ,６６层 ,基础底板总面积为１３８００ｍ２,混凝土总量２５０００ｍ３,由纵横两条１ｍ宽的后浇带划分为４段。塔楼区底板厚３．５ｍ ,面积４７００ｍ２,混凝土量１１７６０ｍ３,需一次性连续浇筑 ,不留施工缝。底板混凝土强度等级Ｃ４０、Ｐ１２ ,垫层为３００ｍｍ厚Ｃ２５毛石混凝土 ,置于中风化和强风化花岗岩地基上。１施工难点浇筑塔楼区底板大体积混凝土 ,要避免出现温度裂缝 ,有以下难点 :（１）混凝土强度等级高 ,所需水泥强度等级亦高 ,用量大 ,产生的水化热大 ;（２）底板超厚 ,体量大 ,混凝土内…     

大块体混凝土温度裂缝的控制

某市钢管厂主轧机基础底板平面尺寸为３８ｍ×４０ｍ,底板厚度分别为１．２ｍ、１．５ｍ、１．８ｍ、２．０ｍ和２．５ｍ,混凝土强度等级为Ｃ２３,抗渗等级为Ｓ８,混凝土一次连续浇筑,浇筑量２０００ｍ３。１混凝土配比设计（１）在满足工程设计要求的前提下,尽量减少单位体积混凝土中的水泥用量,以降低水泥水化热引起的混凝土的水化温升值。（２）满足施工工艺对尚未凝固混凝土的要求,同时减少混凝土浇筑过程的泌水量。（３）减轻混凝土自身养护硬化过程中的收缩,以此降低外约束程度。针对上述原则和工程实际要求,采用了掺加适量粉煤灰及适…     

大体积防辐射混凝土配合比设计与施工质量控制

山西省运城地区医院放疗中心建筑面积１２２０．９５ｍ２,底板厚６００ｍｍ ,混凝土量１９８ｍ３;壁板厚分２０３０ｍｍ、１２００ｍｍ、１２５０ｍｍ三种 ,混凝土量６００ｍ３;顶板厚分１０００ｍｍ及１８００ｍｍ两种 ,混凝土量６００ｍ３。混凝土浇筑总量为１３９８ｍ３,强度等级为Ｃ２０。该工程楼内安装１台钴Ｃｏ６０ 直线加速器 ,为减少对人体的危害 ,设备周围及上顶板、下面筏板基础均采用普通混凝土进行防护 ,属屏蔽混凝土 ,混凝土采用泵送。１技术难点及对策１．１技术难点（１）混凝土一次浇筑量较大 ,必须保证内外温差不超过２…     

C30级粉煤灰超量替代水泥混凝土在大体积混凝土工程中的应用

某工程为地下１层、地上２座２０层的塔楼,全现浇钢筋混凝土剪力墙结构,建筑面积３４０７６ｍ２。地下室底板长１２３．６ｍ,宽６９ｍ,基础底板厚１．５ｍ,混凝土强度等级Ｃ３０,抗渗等级Ｐ６,混凝土一次浇筑量达１２０００ｍ３,属大体积混凝土。１施工方案制订１．１施工方案选择众所周知,大体积混凝土在硬化过程中,由于水泥水化过程产生的水化热而带来的内外温差等原因,会使混凝土裂缝漏水。为解决混凝土干缩和温差裂缝,确保１２３．６ｍ长地下室底板混凝土连续浇筑,不留冷缝,决定在底板中部⑨～⑩轴间,设置一道２０００ｍｍ宽ＵＥＡ补偿…     

核岛厂房底板大体积混凝土温度变化规律探讨

国家某重点科研项目核岛厂房长８２．６５ｍ ,宽６７．００ｍ ,基础底板厚３．０ｍ ,抗渗混凝土强度等级Ｃ３０、Ｐ８。底板混凝土分两层施工（下层厚１．４ｍ ,上层厚１．６ｍ） ,每层分９块 ,共１８块 ,任何相邻两块混凝土浇筑时间间隔不少于１４ｄ。１工程特点底板混凝土配合比为水泥∶水∶砂∶碎石（３１．５ｍｍ）∶粉煤灰∶助泵剂＝３００∶１７６∶７７３∶１０６７∶７５∶３．６ ,入模坍落度１００～１４０ｍｍ。混凝土采用现场搅拌站（现场设两个地下水池）拌制 ,通过地泵及泵管输送到浇筑地点 ,布料杆布料 ,在６、７、１０月份施…     

主电室底板大体积混凝土施工技术措施

主电室底板大体积混凝土施工技术措施宋正利（中国有色六建郑州工程指挥部，４５００４１）宝鸡某压延车间宽板主电室为箱形钢筋混凝土结构，埋入地下６．８ｍ．平面轴线尺寸１０８ｍ×２２．１ｍ。底板用伸缩缝分为１号、２号、３号三部分，底板厚１．８ｍ。仅１号底板平...     

东环广场底板自防水混凝土施工

北京东环广场建筑面积为１８９１６９ｍ２,其中地下部分建筑面积为５５７６０ｍ２。由于工期紧 ,体量大 ,经协商认为基础底板自防水混凝土、自渗井降水效果明显 ,因此取消底板卷材防水层。１防水混凝土的配制底板自防水混凝土共１０５６８ｍ３,掺加粉煤灰及ＵＥＡ -Ｍ型微膨胀剂。浅基底板混凝土厚０．３ｍ ,每立方米混凝土用５２５号水泥３９４ｋｇ,ＵＥＡ -Ｍ掺量１２ % ;深基Ｃ５０、Ｐ８底板混凝土厚１ｍ ,每立方米混凝土用５２５号水泥４３４ｋｇ ,ＵＥＡ -Ｍ掺量１４ %。２底板自防水混凝土的施工要点保证自防水混凝土质量应从控制混…     

浅析高速公路工程招投标中的最低评标价法

结合目前高速公路施工项目招投标活动的实际情况,阐述了最低评标价法的概念,归纳了其优点及存在问题,对完善最低评标价法提出几点策略,以期促进招标投标市场更加规范有序。     

Place-Making in Megaprojects in Melbourne

This article analyses state-led place-making practices in Melbourne. The two levels of government that influence planning in Melbourne make much of the city as ‘culturally vibrant’ and ‘creative’, and have incorporated creative city-inspired place-making principles into many layers of the planning system. An examination of the development of two mixed-use megaprojects in central Melbourne reveals however that ideals of culturally engaging public places, and indeed of creative landscapes for middle-class consumption, wither in the face of more basic imperatives for economic development. In these case studies the ‘creative city’, no matter how the idea is interpreted, has little traction either as a set of inclusive place-making principles or as a gentrification strategy. The article concludes that the creative city-inspired place-making objectives in the planning system at both state and local levels are ambiguous in their overall intents and completely unsupported by statutory controls. Such place-making objectives as are realised are the compromised results of the interplay of uncoordinated decisions, delivered at the pleasure of the developer.     

Pathogens in septage in Vietnam

Septage is widely acknowledged as a major source of infectious pathogens while disposal of septage, and the operation and maintenance of septic tanks, is not regulated in many developing countries. Twenty untreated septage and septage sludge samples were taken from Can Tho City, Vietnam to examine their pathogen content, and indicator micro-organisms. Escherichia coli and Enterococcus spp. were detected in all samples, regardless of sludge storage time. Phages were detected in 80% of samples. Salmonella spp. were detected in 70% of the untreated septage and 60% of septage sludge samples. Concentrations of phages and bacteria tested in septage sludge after many years of tank storage were much higher than the expected levels. Helminth ova were present in 95% of untreated septage samples with an average of 450 ova l^− 1, and were detected in all septage sludge samples with an average of 16,000 ova l^− 1. Twelve varieties of helminth ova were identified. More helminth ova varieties in higher concentrations were found in septage than those reported from stool samples. The varieties' frequency ranged from 10% to 50% and Ascaris lumbricoides predominated. Results show that pathogens and indicator micro-organisms, especially helminth ova, accumulate in sludge. Thus helminth ova should be considered when septage sludge is treated and used for agriculture. Proper health protection measures must be applied for people handling septage.     

在市场中实践在实践中学习在学习中进步--工程公司市场化进程的回顾与展望

近两年来，工程公司在提高市场竞争意识、推动市场化进程中做了大量工作，其中坚持走出去的方针是我们自我加压、推行加快市场化步伐的一个重要战略步骤。     

新时期广东城市化的新特点

新时期广东城市化出现以下特点:知识源导向、城市由单体向群体化发展、产业集群推动、政府主导自上而下的集约化发展、城镇化向城市化转变、由重“数量”发展向重“质量”发展的转变。     

新形势下高校强化基建财务管理的探讨

在市场条件下高校基建财务人员在加强日常财务管理的同时,必须树立起高度的工作责任心,抓好事前监督、事中监督、事后监督三个环节,全面理解、贯彻执行《高等学校财务制度》,管好用好各项基本建设资金,提高基建财务管理水平,更好地完成高校各项基建任务,以有限的投资,最快的建设速度,获得最大的投资效益。     

2005年北京办公物业市场七大趋势

趋势一:CBD区域写字楼集中放量从各区域规划方案上看,CBD区域多数项目在03～04年处于项目的报批手续及拆阶段,预计2005年正式推向市场,因此2005年CBD区域将成为北京市场供应集中的域,区域即将供应的项目有北京财富中心(二期)、金地国际花园、万达广场、SOHO尚都、万通中心、世纪财富中心、怡禾国际中心、光华国际等。除去未知项目,2005CBD写字楼办公面积的供应量为60万平方米左右。中关村区域经过一段时间的集中供后开始逐步放缓,2005年供应的体量相对较大的项目有中关村金融中心、新中关。金街区域可能开盘的项目只有2个:英蓝国际中…     

浅谈我国工程项目建设成本控制存在的问题

结合目前我国施工企业工程项目成本管理现状,对工程项目成本管理过程中存在的问题进行了较详细的分析,并提出了一些解决问题的办法,以做好项目成本控制工作,进而增强企业经济实力。     

Variation in property taxation in Tulsa

Conclusions It may be reasonably concluded from this study that the range of variation in these ratios of assessed to actual value are of a reasonable size for the great majority of cases. The frequency distribution of these sample ratios was not normal, however, as was assumed a process of this type would produce. On the other hand, the failure of the regression analysis to identify any significant variables which would explain these variations would tend to re-enforce the assumption that the fluctuations were indeed of a random nature.To sum it up in one paragraph, aside from a few extreme cases, the assessing process appears to give estimates which are more consistent than would be expected under the assumption that any errors would be of a random nature, but the regression analysis was unable to isolate any particular socioeconomic characteristics which would explain the variation which was present.Financial support for this research project was furnished by the University of Tulsa.