Utilization of high strength concrete for offshore applications

目前的研究计划是开发和优化一种新的裂缝设计准则和最小配筋量，适用于混凝土截面较厚、混凝土覆盖层较厚、钢筋直径较大、配筋率较高的高强混凝土。海上构筑物暴露在恶劣的环境条件下，包括暴露在海水和海浪中，或构筑物存在于飞溅区。对裂缝宽度和钢筋的准确估计可以为单个平台节省数百万美元。现有裂缝宽度计算的大多数表达式都是针对使用标准强度混凝土和标准混凝土覆盖层的建筑结构开发的。然而，海上结构是使用高强度混凝土建造的，混凝土截面厚达500毫米，混凝土覆盖50 - 60毫米。海洋工程中厚截面大覆盖层高强混凝土的裂缝分析研究资料很少。提出的数值阶段的调查将检查与张力和弯曲开裂相关的机制。在持续使用荷载作用下，影响裂缝宽度和裂缝间距的其他因素将进行研究。申请人之前对海上应用的高强度混凝土进行的重要研究将用于准确评估海上结构的开裂特性。

The current research proposal is focused on the development and optimization of a new crack design criteria and minimum reinforcement suitable for high strength concrete with thick concrete cross sections, thick concrete covers, large diameter reinforcement and relatively high reinforcement ratios. Offshore structures are exposed to harsh environmental conditions, including exposure to seawater and sea spray or the structure's existence in the splash zone. An accurate estimate of the crack width and steel reinforcement can result in saving estimated to be in millions of dollars for a single platform. Most of the available expressions for crack width calculations were developed for building structures using normal strength concrete and normal concrete cover. However, offshore structures are built using high strength concrete with thick concrete sections up to 500 mm with 50 - 60 mm concrete cover. Very little research information is published on the crack analysis of high strength concrete with thick concrete section and large concrete cover used for offshore applications. The proposed numerical phase of the investigation will examine mechanisms associated with tension and flexure cracking. Other factors that affect crack width and spacing of cracks under sustained service loads will be examined. Previous important investigations conducted by the applicant on high strength concrete for offshore applications will be utilized to evaluate accurately the cracking properties of offshore structures.