珊瑚骨料混凝土（Coral aggregate concrete，CAC）是一种以珊瑚礁石碎屑代替传统骨料制成的海洋骨料混凝土。在海洋工程及岛礁建设中，使用本地珊瑚礁石碎屑代替碎石、河砂制备混凝土，可以显著降低工程建设成本，缩短工期。为更加深入地了解CAC的力学性质，促进其在实际工程中的应用，本文对CAC在单轴和多轴应力条件下的本构关系进行了一系列研究，并对CAC与纤维增强复合材料（Fiber-reinforced polymer，FRP）筋之间的粘结-滑移关系展开了试验研究。首先，本文结合文献综述与试验分析对珊瑚骨料和CAC的性能进行了简要介绍，包括珊瑚礁石碎屑作为混凝土骨料的基本性能、珊瑚骨料的表面微观构造、CAC的基本力学特性、耐久性能及过渡区微观构造等。随后，本文通过单轴压缩试验研究了CAC在单轴荷载下的性能，并与普通混凝土和轻骨料混凝土进行对比。结果表明：CAC在单轴压缩下脆性较强，与普通混凝土有显著差异，而与轻骨料混凝土类似。这是珊瑚骨料疏松多孔的天然结构与较低的强度造成的。综合试验和文献中的数据，本文提出了适用于CAC的单轴压缩应力-应变模型。针对CAC多轴应力状态下的力学性能，本文对19个CAC试件分别进行了常规三轴和真三轴试验，研究变量包括侧向压力及主应力比、混凝土强度等。CAC的内部破坏主要表现为骨料的破碎，而非水泥石-骨料界面破坏。骨料破碎使混凝土内部出现宏观缺陷，从而导致水泥石的过早破坏，因此相同条件下，CAC三轴强度普遍低于普通混凝土。与本文试验结果的对比表明，已有的轻骨料混凝土多轴破坏准则可以用于描述主动约束下CAC的本构关系。最后，为了探究FRP筋和CAC之间的相互作用机理，对27个FRP筋与CAC试件进行了拉拔试验。试验中出现了三种典型的试件破坏模式：混凝土保护层劈裂、筋材拔出伴有混凝土破坏、筋材表层剥脱。不同的破坏模式和粘结强度可归因于不同的混凝土强度、保护层厚度、筋材几何形状及筋材表面处理。基于试验和文献中的数据，本文提出了分段式模型以描述FRP筋与CAC发生拔出破坏时的粘结本构关系，并对粘结界面上的混凝土进行了力学分析，结合CAC破坏准则提出了特征粘结强度的预测方法。

Coral aggregate concrete is a typical marine aggregate concrete utilizing the local coral rock instead of traditional aggregates. Using local coral rock aggregates in marine construction can substantially reduce the costs and shorten the construction period. To have a better understanding of the mechanical properties of coral aggregate concrete and promote its application in practical engineering, constitutive models of coral aggregate concrete under different loading conditions were developed, including uniaxial compression and triaxial loading. Moreover, the bond-slip behavior between fiber-reinforced polymer bars and coral aggregate concrete were also experimentally studied.First, the properties of coral aggregates and coral aggregate concrete were briefly introduced based on literature review and experimental data, including the properties of coral debris as aggregates, the microstructure of coral aggregates, the mechanical properties and durability of coral aggregate concrete, and the microstructure of interface transition zone.Then the compression behaviors of coral aggregate concrete under uniaxial loading were investigated comparing with lightweight aggregate concrete and ordinary aggregate concrete. The results indicated that the uniaxial compression behaviors of coral aggregate concrete show great brittleness and were different from those of ordinary aggregate concrete but similar to those of lightweight aggregate concrete, for coral rock aggregates are porous and have lower strength than ordinary aggregates. Based on the test data obtained from this research as well as collected from literatures, a stress-strain model was proposed for coral aggregate concrete under uniaxial compression.Subsequently, triaxial tests were performed to 19 coral aggregate concrete specimens to study its mechanical behaviors under triaxial compression. The investigated variables include concrete type, concrete strength, lateral pressure and principal stress ratios. Under triaxial compression, the internal damage of the concrete is the crushing of aggregates instead of damage at the cement-aggregate interface. The crushing of aggregates results in macroscopic defects inside the concrete, which further leads to the premature destruction of cement stones. The test results agree with a failure criterion proposed for lightweight aggregate concrete well.To understand the interaction between fiber-reinforced polymer bars and coral aggregate concrete, 27 pull-out tests were conducted to investigate the bond-slip behavior. Three typical failure modes of specimens were presented: concrete cover splitting, pull-out with damage in concrete, layer of rebar peeling off. Various failures can be attributed to different concrete strength, cover thickness, rebar geometry and surface treatment. A two-branch model is developed to describe the bond stress-slip curves. Moreover, interface mechanics analysises are conducted. Combined with the multiaxial failure criterion of CAC, the analysis approach can be used to determine the characteristic bond strengthes of CAC-FRP bars,