新型碳纤维增强复合材料-钢复合管海水海砂混凝土圆柱轴压试验

为研究原状海水海砂混凝土在复合管混凝土中的应用可行性，提出一种新型由内外壁纤维增强复合材料(FRP)和夹心钢管复合的碳纤维增强复合材料(CFRP)-钢复合管海水海砂混凝土柱结构。对12个新型CFRP-钢复合管海水海砂混凝土圆柱试件进行了轴压试验，研究了CFRP层数和核心混凝土强度等级变化对其轴压性能的影响。试验结果表明，内外壁CFRP的包裹能够有效地提高结构承载力和变形能力；CFRP-钢复合管海水海砂普通混凝土圆柱破坏形态为混凝土压溃，而CFRP-钢复合管海水海砂高强混凝土圆柱破坏形态为剪切破坏；结构的极限应力与CFRP层数、混凝土强度呈正相关，而极限应变随着CFRP层数增加而提高，却随着混凝土强度提高而减小；核心混凝土和钢管对极限应力的贡献随着CFRP层数增加基本不变，且当包裹两层及以上CFRP时，CFRP对试件极限应力的贡献占主导地位。 

Axial compression behavior of new seawater and sea sand concrete filled circular carbon fiber reinforced polymer-steel composite tube columns

In order to study the feasibility of applying the original seawater and sea sand concrete directly to the concrete filled composite tube, a new structure of seawater and sea sand concrete filled carbon fiber reinforced polymer (CFRP) -steel composite tube composed of internal and external fiber reinforced polymer (FRP) and sandwich steel tube was proposed. Twelve new seawater and sea sand concrete filled circular CFRP-steel composite tube columns were tested under axial compression, and the influence of the number of CFRP layers and the strength grade of core concrete on the axial compression performance was studied. The test results show that the wrapping of inner and outer CFRP can effectively improve the bearing capacity and deformation capacity of the structure. The failure mode of common strength seawater and sea sand concrete filled circular CFRP-steel composite tube columns is concrete crushing, while that of high strength seawater and sea sand concrete filled circular CFRP-steel composite tube columns is shear failure. The ultimate stress of the structure is positively correlated with the number of CFRP layers and the strength of concrete. However, the ultimate strain only increases with the number of CFRP layers, but decreases with the strength of concrete. The contribution of core concrete and steel tube to the ultimate stress almost does not change with the increase of the number of layers of CFRP, and the contribution of CFRP to the ultimate stress of specimens is dominant when two or more layers of CFRP are wrapped.