ECC外壳约束海水海砂再生骨料混凝土柱受压性能

针对海水海砂再生骨料混凝土(SSRAC)在柱构件中的应用问题，本研究采用组合设计的方法，提出工程水泥基复合材料(ECC)外壳约束SSRAC柱的形式，对其施行轴心/偏心受压试验.结果显示，ECC外壳可对SSRAC形成良好的约束作用，构件破坏时表现为受压区及受拉区的裂缝宽度增大，材料未压溃.轴心受压时，ECC外壳约束SSRAC柱的峰值荷载相比整浇SSRAC试件提高15%,但其轴向刚度降低；偏心受压时，ECC外壳约束SSRAC柱的变形能力得到提高，在大偏心条件下，极限位移与峰值位移比值较SSRAC柱提高了111%.最后，考虑箍筋、 ECC外壳约束提升作用及其与荷载偏心率的关系，分别提出在轴心/偏心受压作用下柱构件承载能力的计算公式.

Behavior of engineered cementitious composites shell confined seawater sea-sand recycled aggregate concrete column under compressive loading

The study of seawater sea-sand recycled aggregate concrete (SSRAC) can simultaneously alleviate the shortage of river sand resources and the problem of waste concrete disposal. A kind of column can be designed in the form of engineered cementitious composites (ECC) shell confined SSRAC columns, it can make full use of the properties of ECC and isolate the reinforcement from chloride ions in SSRAC, which decreases the risk of corrosion. In this paper, through the experimental and theoretical study of column under axial/eccentric compression, the results show that the ECC shell without stirrups can still have a good confinement effect on SSRAC, which improves its bearing capacity and deformation capacity, and it only shows an increase in crack width in the compressive/tensional zone without crushing when it fails. The bearing capacity under axial compression of ECC shell confined SSRAC column is about 15 % larger than that of SSRAC specimen, however, its axial stiffness decreases. The deformation capacity under eccentric compression of ECC shell confined SSRAC column is improved, the ratio of ultimate displacement to peak displacement under large eccentric compression is increased by 111% compared with that of SSRAC column. Finally, the calculate methods of the bearing capacity under compression is proposed, which considering the confinement of stirrups or ECC shell and its relations with eccentricity ratio.