Data To: Efficient Approach to Measuring Strength and Deformation of Passively Confined Concrete

We present data for a novel experimental method developed to determine the increase in concrete strength and the evolution of both axial and lateral deformation under confined compression. In contrast to expensive and time-consuming triaxial experiments, the present method requires only a uniaxial testing machine with displacement control. In the proposed setup, a concrete cylinder is surrounded by metal rings, which are activated by the lateral expansion of concrete and provide passive confinement. The magnitude of confinement can be easily controlled by the dimensions and spacing of the rings. In contrast to triaxial tests, the stress history is much closer to that encountered in real structural members. The most suitable measuring setup is a combination of conventional and non-contact measurements, namely of the vertical extensometers for the axial strain and digital image correlation (DIC) for the hoop strain. The proposed setup was successfully verified on 20 concrete cylinders 100x200 mm with 4 different aluminum ring layouts. Specimen designation and geometry (ring height is 9 mm in all cases): 8R t2 = 8 rings, ring thickness 2 mm 8R t3 = 8 rings, ring thickness 3 mm 12R t2 = 12 rings, ring thickness 2 mm 12R t3 = 12 rings, ring thickness 3 mm Additional data can be provided on request.

本研究提供了一种新型试验方法的相关数据，该方法用于测定约束受压工况下混凝土的强度提升量，以及轴向与侧向变形的演化规律。与昂贵且耗时的三轴试验不同，本方法仅需配备位移控制功能的单轴试验机即可开展试验。在该试验装置中，混凝土圆柱体被金属环套包裹，金属环会随混凝土的侧向膨胀而被激活，从而提供被动约束作用。约束强度可通过金属环的尺寸与间距便捷调控。与三轴试验相比，该方法得到的应力历程更贴近实际结构构件中的应力状态。该试验最适配的测量方案为接触式与非接触式测量结合，即通过立式引伸计获取轴向应变，通过数字图像相关法（Digital Image Correlation，DIC）获取环向应变。本试验装置已通过20个尺寸为100×200mm的混凝土圆柱体试件完成验证，共设置4种不同的铝制环布置方案。试件编号与几何参数（所有工况下的环高均为9mm）：
8R t2：共8个铝环，环厚2mm；
8R t3：共8个铝环，环厚3mm；
12R t2：共12个铝环，环厚2mm；
12R t3：共12个铝环，环厚3mm。
如有需要，可提供额外试验数据。