随着材料科学的发展、结构跨度和高度的增加，钢筋混凝土构件的尺寸也越来越大，随之而来的尺寸效应问题已成为当今混凝土结构领域重要的基础科学问题。地震作用下，钢筋混凝土柱通常同时承受竖向和横向荷载，并受到扭转效应的影响，长柱延性较好，耗能能力较强，而短柱的结构延性有限，在地震作用下极易发生脆性剪切破坏，进而造成结构的整体坍塌，因此钢筋混凝土短柱的可靠性对整个工程结构的安全性至关重要。针对钢筋混凝土柱抗震性能的研究有很多，但系统讨论尺寸效应对钢筋混凝土柱抗震性能影响的研究则鲜有报道。本项目即是以钢筋混凝土短柱为研究对象，基于物理模型试验和细观数值理论，揭示不同尺寸、不同配箍率钢筋混凝土短柱在低周往复荷载作用下的破坏机制，获得不同力学参数的尺寸效应规律，分析尺寸效应对钢筋混凝土短柱抗震性能的影响，进而修正现行混凝土结构设计理论与方法，提高大尺寸钢筋混凝土构件抗震设计的科学性及合理性。

The structural dimension of reinforced concrete (RC) components is getting larger and larger with the development of materials science, and the increase of the structural span and height. Consequently, size effect becomes a vital basic scientific issue in the field of concrete structure. RC columns should bear not only the vertical and lateral loads, but also the torsional effect under seismic actions. Long columns exhibit good ductility and energy-dissipating capacity. However, short columns could result in a brittle shear failure and the whole collapse of the structure under earthquake, because of the limitation of structural ductility. Therefore, the reliability of short columns is of crucial importance to the safety of the entire engineering structure. Lots of efforts have been made to evaluate the seismic performance of RC columns, however, less have been done to systematically assess the impact of size effect on the seismic performance of RC columns. Herein this project, the RC short column is taken as the research object. Based on the model tests and the mesoscopic numerical theories, the failure mechanism of cyclically loaded RC short columns with different sizes and stirrup ratios will be studied, the size effect rule of different mechanical parameters will be obtained, and the impact of size effect on the seismic performance of RC short columns will be revealed. This project aims at modifying the currently utilized designing theories and methods of concrete structures, and enhancing the scientificity and the rationality of seismic design of large-scale RC components.