【作者】 陈富强；

【导师】 朱洪洲； 陈俊平；

【作者基本信息】 重庆交通大学 ， 工程硕士（专业学位）， 2020， 硕士

【摘要】 海工混凝土结构由于其服役环境恶劣,经常出现过早破坏,造成重大的经济损失。在跨海大桥的应用中,为了确保跨海大桥结构安全并保证其具备设计使用能力,对跨海大桥所用海工高性能混凝土进行材料设计和性能研究非常重要。本文结合厦漳跨海大桥桥面板湿接缝工程实例,通过对混凝土结构常见病害进行分析,得出海工高性能混凝土技术特点。根据海工高性能混凝土基本特征,确定其原材料、试验方法与设计技术指标,并对其进行混凝土材料设计及性能测试,测试结果满足工程使用要求,根据研究得到的海工高性能混凝土对厦漳跨海大桥桥面板湿接缝进行施工。跨海大桥服役环境恶劣,由于钢筋锈蚀、硫酸盐破坏、冻融循环破坏等因素造成海工混凝土耐久性不足,通过采用材料耐久性设计、提高保护层厚度等内部措施以及采用加强钢筋、防腐处理、电化学保护等外部措施及科学的养护管理提升海工混凝土耐久性。海工高性能混凝土配置不同于普通混凝土配置,对于原材料的要求更高。对海工混凝土原材料进行研究,确定配置海工高性能混凝土所需的原材料并进行技术指标测试。通过试验与理论相结合,选择合适的试验方法以及技术指标进行现场试验。根据海工高性能混凝土设计使用目标和配制海工高性能混凝土的基本原则,结合设计规程对海工高性能混凝土进行配合比设计,根据耐久性原则及经济性原则,最终得出厦漳跨海大桥所用海工高性能混凝土设计方案（水泥:矿粉:粉煤灰:砂:碎石:水:外加剂:膨胀剂=340:67:43:668:1134:150:7:50）。根据海工高性能混凝土配合比设计结果拌制海工高性能混凝土并成型相应的混凝土试件,分别进行相关性能测试。测试其坍落度值为180mm,坍落扩展度为460mm,满足设计要求;该混凝土的流动性、粘聚性和保水性良好;水中14d限制膨胀率实测值为3.9×10^-4,水中14d、空气中28d限制干缩率为1.5×10^-4;7d抗压强度为62.0MPa,28d抗压强度为71.2MPa,达到混凝土试配强度的101.9%,28d抗压回弹模量为4.7×10⁴MPa;抗压强度、弹性模量等力学性能以及抗氯离子渗透性能、抗早期开裂性能等耐久性均满足设计使用要求。结合厦漳跨海大桥服役的气候条件及工程建设要求,采用合适的施工工艺,合理的资源配置,以及贯穿全过程中的质量控制,完成厦漳跨海大桥第Ⅵ合同段桥面板湿接缝施工。本文通过采用试验及工程实际相结合,得出海工高性能混凝土材料配合比设计方案,并通过相关试验对配合比设计方案得出的海工高性能混凝土进行性能测试,并成功运用于桥面板湿接缝施工。通过对海工混凝土的配合比设计研究并对性能进行评价,为后续海工混凝土结构物建造具有指导意义,对海工高性能混凝土的的发展提供一定的借鉴意义。更多还原

【Abstract】 Due to the harsh service environment of marine engineering concrete structures, the structure often fails prematurely,causing significant economic losses.In the application of the cross-sea bridge,in order to ensure the safety of the cross-sea bridge structure and ensure that it has the ability to design and use,it is very important to conduct material design and performance research on offshore high-performance concrete.In this paper,combined with the example of the wet joint project of the deck of the Xia-Zhang cross-sea bridge,through analyzing the common diseases of the concrete structure,the technical characteristics of offshore high-performance concrete are obtained.According to the basic characteristics of offshore engineering high-performance concrete,determine its raw materials,test methods and design technical indicators,and perform concrete material design and performance tests on it,the test results meet the engineering use requirements,according to the obtained marine engineering high-performance concrete to Xia Zhang Construction of wet joints of bridge decks of sea-crossing bridges.The service environment of the concrete structure is harsh.Due to factors such as steel bar corrosion,sulfate damage,and freeze-thaw cycle damage,the durability of marine concrete is insufficient.Through internal measures such as material durability design,increased protective layer thickness,and the use of reinforced steel,anti-corrosion treatment,electrical External measures such as chemical protection and scientific maintenance management can improve the durability of marine concrete.The configuration of offshore engineering high performance concrete is different from that of ordinary concrete,and the requirements for raw materials are higher.Research on the raw materials of offshore engineering concrete,determine the raw materials required for the configuration of offshore engineering high-performance concrete and test the technical indicators.Through the combination of test and theory,select the appropriate test method and design technical indicators for field test.According to the design and use goals of offshore engineering high-performance concrete and the basic principles of preparing offshore engineering high-performance concrete,the design of the mix proportion of offshore engineering high-performance concrete in combination with the design regulations,based on the principles of durability and economy,the Xiazhang cross-sea The design scheme of marine high-performance concrete used in the bridge（cement:mineral powder:fly ash:sand:crushed stone:water:admixture:expansion agent=340:67:43:668:1134:150:7:50）.According to the design results of the marine high-performance concrete mix ratio,the marine high-performance concrete is mixed and the corresponding concrete test pieces are formed,and the relevant performance tests are conducted respectively.The slump value of the test is 180mm,and the slump expansion is 460mm,which meets the design requirements;the concrete has good fluidity,cohesiveness and water retention;the measured expansion rate of 14d in water is 3.9×10^-4 and 14d in water 2.The 28d limiting shrinkage rate in air is 1.5×10^-4;the 7d compressive strength is 62.0MPa,the 28d compressive strength is 71.2MPa,reaching 101.9%of the concrete test strength,and the28d compressive rebound modulus is 4.7×10⁴MPa;mechanical properties such as compressive strength,elastic modulus,durability against chloride ion penetration,and resistance to early cracking all meet the design and use requirements.Combined with the climatic conditions and engineering construction requirements of the Xia-Zhang Sea-crossing Bridge in service,using appropriate construction techniques,reasonable resource allocation,and quality control throughout the entire process,the bridge deck wet joints of the Xia-Zhang Sea-crossing Bridge Section VI contract were completed construction.In this paper,through the combination of testing and engineering practice,the design scheme for the mix ratio of marine high-performance concrete materials is obtained,and the performance test of the marine high-performance concrete obtained by the mix ratio design plan is carried out through relevant tests and successfully applied to the wet of bridge deck Seam construction.Through the research and design of the mix ratio of marine concrete and the evaluation of its performance,it will be of guiding significance for the subsequent construction of marine concrete structures and provide a certain reference for the development of marine high-performance concrete.更多还原