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1、超长超大面积混凝土结构裂缝控制技术摘要：广东奥林匹克体育场是九运会的主会场，设固定观众座位8万席，总建筑面积达1456万m2，规模巨大，造型新颖，质量标准高，施工难度大，工期短，由广东建工集团总承包施工，本工程(包括场外环境及附属结构)高性能混凝土用量达13万m3。本工程面积巨大的环状结构看台楼层采用现浇混凝土结构，由于其特殊功能要求，花瓣形看台面积达425万m。，属超大面积钢筋混凝土结构关键词：大面积混凝土结构裂缝控制技术1工程概况广东奥林匹克体育场是九运会的主会场，设固定观众座位8万席，总建筑面积达1456万m2，规模巨大，造型新颖，质量标准高，施工难度大，工期短，由广东建工集团总承包施工
2、，本工程(包括场外环境及附属结构)高性能混凝土用量达13万m3。本工程面积巨大的环状结构看台楼层采用现浇混凝土结构，由于其特殊功能要求，花瓣形看台面积达425万m。，属超大面积钢筋混凝土结构。看台下各楼层面积分别为：首层379万m。，2层284万m2，3层152万m。，4层14万nfl。，5层124万m2。看台楼层沿径向设计有6道永久性伸缩缝，其间距超长，约为90m。地下室底板面积近25万m。，浇筑混凝土量达187万m3，虽然其厚度仅为600mm，但分布其中的众多大承台和底板合在一起浇筑施工，合并后的最大厚度达17m，亦属大体积混凝土施工。底板设计有7条后浇带，分为8大块，最大一块面积达410
3、0m。，底板宽约36m，长约120m，底板后浇带间距超长。超长、超大面积及大体积混凝土是本工程结构的重要特色之一，其裂缝控制也就成为工程施工的重点与难点。2采用高性能混凝土施工技术本工程混凝土最大输送距离达300m，最大输送高度为60m，为满足泵送混凝土和体育场复杂特殊造型的施工要求，我们大量采用了高性能混凝土施工技术。在体育场北区配置了l台意大利进口的大型现代化搅拌站，产量为90mh；南区配置了自动上料和自动称量系统的混凝土搅拌站2座，产量为3050m3h。针对本工程的需要，配制高性能混凝土时为了优选原材料和配合比，我们应用“双掺”技术，除提高混凝土的可泵性外，还有意识地预先通过试验确定低收
4、缩率的混凝土配合比，同时减少水泥用量，降低混凝土的水化热和改善其收缩性能。21优选原材料选用优质的原材料，如底板施工中采用连续级配骨料，增大混凝土的密实度。严格控制混凝土出机和人泵坍落度，随不同施工阶段的设计要求与天气变化情况跟踪调整配合比，详见表1。22采用“双掺技术在本工程施工中，地下室底板使用KFDN-SP8外加剂，看台楼层等混凝土结构根据具体情况，选用HPM一2高效缓凝减水剂、FEC2外加剂等，这些高效外加剂具有高减水率和良好的保塑性能。掺外加剂混凝土与基准混凝土的减水效应比较如图1所示。根据本工程的具体情况，我们分别选用黄埔电厂、广州发电厂等的I级或级粉煤灰，采用粉煤灰这种活性的水硬
5、性材料代替部分水泥，补充泵送混凝土中的细骨料，提高混凝土的抗渗性、耐久性和流动性，并改善其可泵性和降低水化热，从而提高混凝土的后期强度。23配合比选择混凝土的配合比决定了混凝土的强度、抗渗性、和易性、坍落度、水泥用量、水化热大小、初凝和终凝时间以及混凝土收缩率等性能指标。根据结构的不同特点和设计要求、气候条件，掺人粉煤灰的影响以及施工现场的生产管理状况，采用不同技术指标，由实验室试配确定。(1)地下室底板施工阶段根据现场条件，对底板混凝土提出以下指标：坍落度1214cm；初凝时间68h；掺加高效减水剂，超量掺加I级粉煤灰，减少水泥用量，降低水化热；通过试验选定收缩率较小的配合比。为了确保混凝土
6、具有高性能，我们提前对混凝土配合比进行了大量反复多次的试验，取得十几组试配数据，测试了不同配合比混凝土的收缩率及收缩与龄期的关系，并采用钢环试验方法测试混凝土的长期收缩情况。测定混凝土收缩率后，有意识地模拟浇筑一块混凝土试件进行试验，测试其温度变化和收缩率，确定了表2的配合比，其收缩率为0120，且在14d后基本上不再收缩。实践证明，本配合比是成功的，用I级粉煤灰代替部分水泥，大大减少了水泥用量和降低了水化热，在确定了收缩率较小的配比后，据此收缩率确定底板分块的最大长度为45m，相邻块之间混凝土浇筑的时间间隔为14d。(2)看台楼层选择不同的水泥和多种外加剂进行配合比试验研究，对外加剂的适应性
7、进行对比试验，得出针对不同阶段和不同施工部位的优化配合比。北区采用深圳产FEC2外加剂掺量为16，黄埔电厂的级粉煤灰掺量为22，既满足了混凝土的强度要求，又具有良好的可泵性和经济性。南区采用HPM一2高效缓凝减水剂和黄埔电厂的级粉煤灰得出的配合比，即：水泥：混合材：砂：石：水：外加剂=l：023：217：320：053：0016，水泥、砂、石、水、粉煤灰、外加剂用量分别为332，722，1063，176，77，528m3，水胶比044，含砂率404，坍落度145mm，质量密度2370kgm3，初凝n,-Jlq58h，终凝时间810h。3合理增加施工缝数量以改善约束条件在超大面积现浇底板、看台和
8、楼层中，通过合理增加施工缝数量，降低了约束应力，减少了混凝土收缩，取得良好的效果。31地下室底板为了有效控制混凝土底板的收缩变形，施工前经计算和研究，决定调整底板分块，将大块底板划分成小块进行施工，中间增加19条施工缝，把整个底板划分成27小块，每块长度基本上控制在45m内，底板后浇带按设计要求采用橡胶止水片，施工缝和侧墙后浇带及外墙水平施工缝采用钢板止水片。后浇带、施工缝采用新型永久性模板快易收口网。后浇带待其两侧混凝土龄期达2个月后再施工，采用比设计高一等级的微膨胀混凝土浇筑。底板混凝土的浇注采用跳仓法进行，相邻两块底板混凝土浇注时间间隔为14d，实践证明收到了很好的效果。32看台楼层本工
9、程形体庞大，看台楼层面积巨大，环状结构超长，为防止混凝土贯通裂缝的产生，并有效控制表面裂缝的开展，施工过程中在不影响结构整体性的前提下，兼顾施工方便，沿体育场看台和楼层环向增设了两道施工缝，缝处增设构造配筋，合理划分施工流水段，使施工缝有效削减了混凝土结构的约束应力，减少了蓄热量与水化热的过度积累，避免了有害裂缝的产生。53（英文版 ） Two regulations promulgated for implementation is in the party in power for a long time and the rule of law conditions, the implem
10、entation of comprehensive strictly strategic plan, implementation in accordance with the rules and discipline to manage the party, strengthen inner-party supervision of major initiatives. The two regulations supporting each other, the adhere to a positive advocate, focusing on morality is of Party m
11、embers and Party leading cadres can see, enough to get a high standard; around the party discipline, disciplinary ruler requirements, listed as negative list, focusing on vertical gauge, draw the party organizations and Party members do not touch the bottom line . Here, the main from four square fac
12、e two party rules of interpretation: the first part introduces two party Revised regulations the necessity and the revision process; the second part is the interpretation of the two fundamental principles of the revision of laws and regulations in the party; the third part introduces two party regul
13、ations modified the main changes and needs to grasp several key problems; the fourth part on how to grasp the implementation of the two regulations of the party. and revised the necessity and revised history of the CPC Central Committee the amendment to the Chinese Communist Party members and leadin
14、g cadres honest politics several guidelines and column 1 by 2015 to strengthen party laws and regulations focus. Two party regulations revision work lasted a Years, pooling the wisdom of the whole party, ideological consensus, draw historical experience, respect for the wisdom of our predecessors, w
15、hich reflects the unity of inheritance and innovation; follow the correct direction, grasp the limited goals, adhere to the partys leadership, to solve the masses of the people reflect a focus on the problem. The new revision of the and , reflects the partys 18 and the eighth session of the third, t
16、he spirit of the fourth plenary session, reflecting the experience of studying and implementing the General Secretary Xi Jinping series of important speech, reflects the partys eighteen years comprehensive strictly practice. (a) revised two regulations of the party need of in based on revised, the p
17、romulgation and implementation of January 2010, to strengthen the construction of the contingent of leading cadres play an important role. But with the party to manage the party strictly administering the deepening, has not been able to fully meet the actual needs. Content is too complicated, eight
18、prohibition, 52 are not allowed to hard to remember, and also difficult to put into practice; the second is concisely positive advocated by the lack of prohibited provisions excessive, no autonomy requirements; the third is banned terms and discipline law, both with the party discipline, disciplinar
19、y regulations repeat and Criminal law and other laws and regulations repeat; the fourth is to clean the theme is not prominent, not for the existing problems, and is narrow, only needle of county-level leading cadres above. is in 1997 based on revision, in December 2003 the promulgation and implemen
20、tation, to strengthen the construction of the party play very important role. Along with the development of the situation, which many provisions have been unable to fully meet the comprehensive strictly administering the practice needs. One is Ji law, more than half of the provisions and criminal la
21、w and other countries laws and regulations Repetition; two is the political discipline regulations is not prominent, not specific, for violation of the party constitution, damage the authority of Party Constitution of misconduct lack necessary and serious responsibility to pursue; third is the main
22、discipline for the leading cadres, does not cover all Party members. Based on the above situation, need to and the two is likely to be more relevant regulations first amendment. By revising, really put the authority of Party discipline, the seriousness in the party tree and call up the majority of P
23、arty members and cadres of the party constitution of party compasses party consciousness. (II) two party regulations revision process the Central Committee of the Communist Party of China attaches great importance to two regulations revision . Xi Jinping, general books recorded in the Fifth Plenary
24、Session of the eighth session of the Central Commission for Discipline Inspection, on the revised regulations made clear instructions. According to the central deployment, the Central Commission for Discipline Inspection from 2014 under six months begin study two regulations revision. The Standing C
25、ommittee of the Central Commission for Discipline Inspection 4 review revised. Comrade Wang Qishan 14 times held a special meeting to study two regulations revision, amendment clarifies the direction, major issues of principle, path and target, respectively held a forum will listen to part of the pr
26、ovince (area) secretary of the Party committee, Secretary of the Discipline Inspection Commission, part of the central ministries and state organs Department The first party committee is mainly responsible for people, views of experts and scholars and grassroots party organizations and Party members
27、. Approved by the Central Committee of the Communist Party of China, on 7 September 2015, the general office of the Central Committee of the Party issued a notice to solicit the provinces (autonomous regions, municipalities) Party, the central ministries and commissions, state ministries and commiss
28、ions of the Party (party), the General Political Department of the military, every 3 people organization of Party of two regulations revision opinion. Central Commission for Discipline Inspection of extensive solicitation of opinions, careful study, attracting, formed a revised sent reviewers. In Oc
29、tober 8 and October 12, Central Committee Political Bureau Standing Committee and the Political Bureau of the Central Committee After consideration of the two regulations revised draft. On October 18, the Central Committee of the Communist Party of China formally issued two regulations. Can say, two
30、 laws amendment concentrated the wisdom of the whole party, embodies the party. Second, and revision of the basic principles of two party regulations revision work and implement the partys eighteen, ten eight plenary, the spirit of the Fourth Plenary Session of the Eleventh Central Committee and Gen
31、eral Secretary Xi Jinping important instructions on the revised and , highlighting the ruling party characteristics, serious discipline, the discipline quite in front of the law, based on the current, a long-term, advance as a whole, with Bu Xiuding independent and . Main principle is: first, adhere
32、 to the party constitution to follow. The constitution about discipline and self-discipline required specific, awaken the party constitution of party compasses party consciousness, maintaining the authority of the constitution. General Secretary Xi Jinping pointed out that no rules, no side round. P
33、arty constitution is the fundamental law, the party must follow the general rules. In early 2015 held the eighth session of the Central Commission for Discipline Inspection Fifth Plenary Session of the 16th Central Committee, Xi Jinping again pointed out that constitution is the party must follow th
34、e general rules, but also the general rules. the revision of the and is Method in adhere to the regulations established for the purpose of combining rule of virtue is to adhere to the party constitution as a fundamental to follow, the constitution authority set up, wake up the party constitution and
35、 party rules the sense of discipline, the party constitution about discipline and self-discipline specific requirements. 4 second is to adhere to in accordance with the regulations governing the party and the party. The Party of rule of virtue de, mainly refers to the partys ideals and beliefs, exce
36、llent traditional style. The revised the closely linked to the self-discipline, insisting on the positive initiative, for all members, highlight the vital few, emphasized self-discipline, focusing on the morality, and the majority of Party members and the ideological and moral standards. The revised
37、 Ji method separately, Ji, Ji Yan to Method, as a negative list, emphasizing the heteronomy, focusing on vertical gauge. Is this one high and one low, a positive reaction, the strict party discipline and practice results transformation for the integration of the whole party to observe moral and disc
38、ipline requirements, for the majority of Party members and cadres provides benchmarking and ruler. Third, insist on to. In view of the problems existing in the party at the present stage, the main problems of Party members and cadres in the aspect of self-discipline and abide by the discipline to ma
39、ke clearly defined, especially the partys eighteen years strict political discipline and political rules, organization and discipline and to implement the central eight provisions of the spirit against the four winds and other requirements into Disciplinary provisions. Not one pace reachs the design
40、ated position, focusing on in line with reality, pragmatic and effective. After the revision of major changes, major changes in the and modified and needs to grasp several key problems (a) adhere to according to regulations governing the party and party with morals in combination, for at the present
41、 stage, the leadership of the party members and cadres and Party members in existing main problems of self-discipline, put forward principles, requirements and specifications, showing Communists noble moral pursuit, reflected at all times and in all over the world ethics from high from low 5 common
42、requirements. One is closely linked to the self-discipline, removal and no direct relation to the provisions of . the second is adhere to a positive advocate, eight prohibition 52 are not allowed to about the content of the negative list moved into synchronization amendment . Three is for all the pa
43、rty members, will apply object from the leadership of the party members and cadres to expand to all Party members, fully embodies the comprehensive strictly required. The fourth is prominent key minority, seize the leadership of the party members and cadres is the key, and put forward higher require
44、ments than the ordinary Party members. Five is to simplify, and strive to achieve concise, easy to understand, easy to remember. The revised is the ruling Party since the first insists on a positive advocate forAll Party members and the self-discipline norms, moral declaration issued to all members
45、of the party and the National Peoples solemn commitment. criterion of a clean and honest administration consists of 4 parts, 18, more than 3600 words. After the revision of the , a total of eight, 281 words, including lead, specification and Party member cadre clean fingered self-discipline norms, e
46、tc. Part 3 members low-cost clean and self-discipline, the main contents can be summarized as four must eight code. Lead part, reiterated on ideal and faith, fundamental purpose, the fine traditions and work style, noble sentiments, such as four must the principle of requirements, strong tone of sel
47、f-discipline, The higher request for 6 and supervised tenet, the foothold in permanent Bao the partys advanced nature and purity, to reflect the revised standards requirements. Members of self-discipline norms around the party members how to correctly treat and deal with the public and private, cheap and rot thrifty and extravagance bitter music, put forward the four norms. Party leader cadre clean fingered self-discipline norms for the leadership of the party members and cadres of the vital fe