Behaviour of beam–column joints made of recycled-aggregate concrete under cyclic loading

Three recycled aggregate concrete (RAC) beam-column interior-joint specimens (including two modified recycled aggregate concrete interior joints with replacement of fly ash ratio of 15%) were tested under cyclic loading in order to study the bond behavior of the longitudinal steel bar at RAC joint. The tests obtained load-strain hysteresis curves of longitudinal bars. The relative bond strength of longitudinal bar in characteristic stages was calculated. The test results indicated that the longitudinal steel bar in RAC joint is able to supply a stable bond stress both in the full crack stage and in the ultimate stage, meaning that the requirements of stress transferring and displacement coordinating between RAC and reinforcements can be satisfied. The larger the diameter of steel bar, the more serious the bond strength degradation. The RAC with fly ash can improve the interface compactness and bond strength of recycled aggregate in full crack stage. When beam-column interface of concrete compression zone reaches ultimate strain, the compressive stress of the longitudinal reinforcement cannot be exerted. The bond stress of the steel bar cannot realize the pull and compressive stress conversion in the length of the core area of the joint owing to the stress hysteresis of the compression rebars.

Download Full-text

Compressive stress-strain relation of recycled aggregate concrete under cyclic loading

Construction and Building Materials ◽

10.1016/j.conbuildmat.2018.10.137 ◽

2018 ◽

Vol 193 ◽

pp. 72-83 ◽

Cited By ~ 6

Author(s):

Xiaobin Hu ◽

Qinwang Lu ◽

Zihao Xu ◽

Wenliang Zhang ◽

Shanshan Cheng

Keyword(s):

Cyclic Loading ◽

Compressive Stress ◽

Recycled Aggregate Concrete ◽

Recycled Aggregate ◽

Stress Strain ◽

Aggregate Concrete ◽

Strain Relation ◽

Stress Strain Relation

Download Full-text

Effect of recycled aggregate concrete on the seismic behavior of DfD beam-column joints under cyclic loading

Advances in Structural Engineering ◽

10.1177/1369433220982729 ◽

2020 ◽

pp. 136943322098272

Author(s):

Jianzhuang Xiao ◽

Zixuan Chen ◽

Tao Ding ◽

Bing Xia

Keyword(s):

Cyclic Loading ◽

Carbon Emission ◽

Recycled Aggregate Concrete ◽

Recycled Aggregate ◽

Total Carbon ◽

Force Model ◽

Aggregate Concrete ◽

Column Joint ◽

Loading Tests ◽

Cyclic Loading Tests

The problem of environmental pollution and waste concrete generation will be alleviated if concrete structures can be designed with both recycling and reuse strategies. In this regard, this study employed recycled coarse aggregate as the structural material in a novel beam-column joint with Design for Deconstruction (DfD) connections. Two series cyclic loading tests including pre-loading and re-loading on this frame joint was undertaken and the effect of recycled aggregate concrete (RAC) on structural behaviors was carefully evaluated. It is demonstrated that the DfD joint with RAC had favorable integrity and the influence of RAC was acceptable for practical application. Furthermore, the shear force model of the joint core area for RAC beam-column joint with DfD connections was put forward in this study, which showed good agreements with experimental results. Life cycle assessment (LCA) indicated that the carbon emission of the beam-column joint with DfD connections made of RAC increased at construction process but would reduce the total carbon emission from the perspective of lifetime.

Download Full-text

Recycled aggregate concrete filled steel SHS beam-columns subjected to cyclic loading

Steel and Composite Structures ◽

10.12989/scs.2009.9.1.019 ◽

2009 ◽

Vol 9 (1) ◽

pp. 19-38 ◽

Cited By ~ 27

Author(s):

You-Fu Yang ◽

Lin-Tao Zhu

Keyword(s):

Cyclic Loading ◽

Recycled Aggregate Concrete ◽

Recycled Aggregate ◽

Aggregate Concrete ◽

Beam Columns

Download Full-text

Uniaxial Damaged Plastic Constitutive Relation of Recycled Aggregate Concrete

Advances in Materials Science and Engineering ◽

10.1155/2019/2982195 ◽

2019 ◽

Vol 2019 ◽

pp. 1-16

Author(s):

Xiaobin Hu ◽

Qinwang Lu ◽

Shanshan Cheng

Keyword(s):

Mechanical Properties ◽

Cyclic Loading ◽

Constitutive Relation ◽

Coarse Aggregate ◽

Experimental Studies ◽

Recycled Aggregate Concrete ◽

Recycled Aggregate ◽

Peak Strain ◽

Test Results ◽

Aggregate Concrete

This paper presents a proposed uniaxial damaged plastic constitutive relation of recycled aggregate concrete (RAC) based on the experimental studies. A total of five groups of RAC specimens with different recycled coarse aggregate (RCA) replacement percentages of 0, 25%, 50%, 75%, and 100%, respectively, are tested under both monotonic loading and cyclic loading. The effect of the RCA replacement percentage is thoroughly investigated on a variety of mechanical properties, including the compressive strength, the peak strain, and the elastic modulus. Based on the test results, a uniaxial damage plastic constitutive relation of the RAC is proposed within the continuous thermodynamics framework. After validated by the experimental results, the proposed damaged plastic constitutive relation of the RAC is applied to perform nonlinear analysis of the RAC columns under cyclic loading, which provides close predictions of the hysteresis behavior of the RAC columns.

Download Full-text