Utilization of high strength concrete for offshore applications

目前的研究方案集中在开发和优化适用于厚混凝土截面、厚混凝土保护层、大直径钢筋和较高配筋率的高强混凝土的新的裂缝设计标准和最小配筋量。近海结构物暴露在恶劣的环境条件下，包括暴露在海水和海水喷雾中，或者结构物存在于飞溅区。对裂缝宽度和钢筋的准确估计可以导致单个平台节省数百万美元。现有的裂缝宽度计算公式大多适用于使用普通强度混凝土和普通混凝土保护层的建筑结构。然而，海上结构物是使用高强度混凝土建造的，混凝土截面厚达500毫米，混凝土保护层为50-60毫米。近海应用的厚混凝土截面、大混凝土保护层的高强混凝土裂缝分析的研究资料很少。拟议的数值阶段的调查将审查与拉伸和弯曲开裂有关的机制。还将研究在持续使用载荷下影响裂缝宽度和裂缝间距的其他因素。申请人以前对用于海上应用的高强混凝土进行的重要调查将被用来准确地评估海上结构物的开裂性能。

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.