Abstract
In this study, the strengthening effect of a buckling-restrained X-shaped steel panel damper (BRPD) with cover
plates on the shear response of a non-seismic reinforced concrete (RC) frame is verified. A non-strengthened RC frame and three
RC frames strengthened with a BRPD were tested under constant axial and cyclic lateral loads. The main parameters were the
connection method between the RC frame and the H-shaped frame connected to the BRPD, including in- and side-plane
strengthening. Test results showed that in-plane strengthening using the BRPD effectively reduced the pinching effect, as
indicated by a wide hysteresis loop in each cycle of the lateral load–displacement relationship. Consequently, the shear capacity,
cumulative dissipated energy at the 80% of peak load in the post-peak behavior, and equivalent damping ratio of the in-plane
strengthened RC frames using the H-shaped frame connected to the BRPD were 1.72, 5.15, and 2.18 times higher, respectively,
than those of the non-strengthened RC frame.
Address
Yeon-Back Jung:Hyundai Engineering and Construction, Seoul, South Korea
Ju-Hyun Mun:Department of Architectural Engineering, Kyonggi University, Suwon, Gyonggi-do, South Korea
Jae-Il Sim:Korea Disaster Prevention Safety Technology Co., Ltd, Gwangju, Jeollanam-do, South Korea
Seung-Hyeon Hwang:Department of Structural Engineering Research, Korea Institute of Civil Engineering and Building Technology (KICT), Goyang, Gyonggi-do, South Korea
Sanghee Kim:Department of Architectural Engineering, Kyonggi University, Suwon, Gyonggi-do, South Korea
Do-Bum Kim:N.I STEEL Co., Ltd. R&D Center, Seoul, South Korea
Abstract
To reveal the failure mechanism of reinforced concrete columns under cyclic loading of compression, bending,
shear span, reinforcement ratio and stirrup ratio, the low cycle cyclic loading tests of six specimens were completed with
synchronous but different displacement amplitude loading modes, and the test data were obtained to analyze the influence of
various parameters on seismic performance. The test results show that: cracks are mainly concentrated in the middle and lower
section of the specimen, showing oblique cross form, and the failure mode is mainly in the bending and torsion failure mode;
with the increase of torsion bending ratio and reinforcement ratio, the torque torsion angle hysteretic curve of the specimen is
fuller and has strong energy dissipation capacity; with the increase of shear span ratio, the torque torsion angle hysteretic curve
of the specimen presents a pinching shape, and the energy consumption capacity becomes worse, but it changes later The
flexural ductility and energy dissipation capacity of the specimens can be improved by increasing the torsion bending ratio,
reinforcement ratio and stirrup ratio, and the degradation of strength and stiffness can be delayed.
Key Words
compression bending shear torsion; hysteretic performance; reinforced concrete column; shear span ratio;
torsion bending ratio
Address
Juntao Li:College of Civil Engineering and Architecture, Guangxi University, Nanning 530004, P. R. China
Guowei Lao:College of Civil Engineering and Architecture, Guangxi University, Nanning 530004, P. R. China
Zongping Chen:1)College of Civil Engineering and Architecture, Guangxi University, Nanning 530004, P. R. China
2)Key Laboratory of Disaster Prevention and Structural Safety of Ministry of Education, Guangxi University, Nanning 530004, P. R. China
3)Nanning Engineering Technology Research Center of Environment-Friendly Building Materials and Building Performance Enhancement,
Nanning University, Nanning 530200, P. R. China
Ji Zhou:College of Civil Engineering and Architecture, Guangxi University, Nanning 530004, P. R. China
Yuliang Chen:College of Civil Engineering, Guangxi University of Science and Technology, Liuzhou 545006, P. R. China
Abstract
Due to their outstanding performance, the application of precast encased composite flexural members is becoming
increasingly widespread in large-scale infrastructure. There is a lack of research or design guidance on the fatigue performance
of precast encased composite beams having welded-on shear studs (ECB-S), making it difficult to accurately evaluate their
fatigue behavior. This paper reports an experimental study of the high-cycle fatigue behavior of ECB-S subject to flexure. The
fatigue failure process, development of strain and deformation, fracture morphology and fatigue life were examined. The
similarities and differences of fatigue performance between ECB-S and bare steel beams, as well as encased composite beams
having no welded anchors, were compared. The study illustrates the expected behavior of such ECB-S as being governed by the
fatigue behavior of the reinforcing bars present in the embedding concrete; behavior is well-predicted by existing relationships
for reinforcing bar fatigue in concrete. Upon fracture of the reinforcing bars, forces are redistributed to the embedded steel
section, increasing the stress range on this element whose subsequent fatigue performance is affected by the presence of welded
on studs – behavior also well-predicted by existing relationships. Evaluation of a larger data base of comparable test results
reinforced the findings of the experimental portion of this study and allowed design recommendations to be presented for ECB
S. This study provides a reference for the engineering application of ECB-S under fatigue conditions.
Address
Shun Xiao:Shanghai Key Laboratory of Engineering Structure Safety, Shanghai Research Institute of Building Sciences Co., Ltd., 75 South Wanping Road, Shanghai 200032, China
Xiangmin Li:Shanghai Key Laboratory of Engineering Structure Safety, Shanghai Research Institute of Building Sciences Co., Ltd., 75 South Wanping Road, Shanghai 200032, China
Kent A. Harries:Department of Civil and Environmental Engineering, University of Pittsburgh, 4200 Fifth Avenue, Pittsburgh, PA 15260, USA
Zhuolin Wang:Shanghai Key Laboratory of Engineering Structure Safety, Shanghai Research Institute of Building Sciences Co., Ltd., 75 South Wanping Road, Shanghai 200032, China
Yubing Leng:Shanghai Key Laboratory of Engineering Structure Safety, Shanghai Research Institute of Building Sciences Co., Ltd., 75 South Wanping Road, Shanghai 200032, China
Qingfeng Xu:Shanghai Key Laboratory of Engineering Structure Safety, Shanghai Research Institute of Building Sciences Co., Ltd., 75 South Wanping Road, Shanghai 200032, China
Abstract
In this study, we examined the repurposing of waste polyethylene terephthalate (PET) as a base material in
prestressed high-strength concrete (PHC) piles by mixing it with different weight ratios (10-30%) of waste polycarbonate (PC).
The specimens were prepared after determining their cross-sections, and their tensile strength, compressive strength, Izod impact
strength, and Rockwell hardness were evaluated according to the ASTM standards. Furthermore, finite element analysis (FEA)
was performed on the waste PET and PC specimens to evaluate their applicability as a base material for PHC piles. The FEA
results revealed a 2.8-times increase in the load-bearing capacity of the mixed-material specimens with no considerable impact
owing to the mixing ratios. Consequently, the amalgamation of waste PET and PC can effectively serve as a viable base material
for PHC piles, thereby securing pile stability through heightened vertical stress resistance.
Key Words
finite element analysis; polycarbonate flake; prestressed high-strength concrete; reinforcement; waste
polyethylene terephthalate
Address
Hongseok Jang:Department of Architectural Engineering, Korea Polytechnics, 85 Haseo-ro, Buk-gu 61099, Research Center of industrial Technology, Jeonbuk National University, Jeonju 54896, Republic of Korea
Daesung Cho:Technical Development Department, N-Genius Co. Ltd., 4-22 Naebang-gil, Bogae-myeon, Anseong-si 17508, Republic of Korea
Abstract
Many cold-formed steel (CFS) structures suffer from severe corrosion in long-term corrosive environments, which
leads to the degradation of elastic buckling performance. Finite element (FE) models are developed to investigate the influence
of corrosion region, size, and position on the elastic distortional buckling stress of corroded CFS columns. Based on the
deformation characteristics of corroded columns, a calculation method for predicting elastic distortional buckling stress is
proposed, and the predicted values are validated against the FE analysis results. The findings indicate that lip corrosion has the
most pronounced effect on elastic distortional buckling stress, followed by web corrosion, while flange corrosion exerts the least
influence. It is also observed that the length of the corrosion area significantly affects buckling stress when it falls within one
half-wavelength of the column, suggesting a strong correlation between corrosion extent and the structural mode shape. In
contrast, the distance of the corroded region from the transverse centerline of the web has only a minor effect. However, when
corrosion is located near the web-flange junction, its influence on the buckling behavior becomes notably greater. When the
corrosion area is located away from the column end, the distance from the longitudinal centerline has a limited impact on the
elastic distortional buckling stress. However, when the corrosion region is near the column end, boundary conditions restrict
distortional buckling deformation. The proposed calculation method provides accurate predictions of the elastic distortional
buckling stress of corroded CFS columns.
Key Words
calculation method; cold-formed steel; corrosion; distortional buckling
Address
Biao Nie:Jiangxi Provincial Key Laboratory of Comprehensive Stereoscopic Traffic Information Perception and Fusion,
East China, Jiaotong University, Jiangxi, China
Dongzhou Huang:Jiangxi Provincial Key Laboratory of Comprehensive Stereoscopic Traffic Information Perception and Fusion, East China, Jiaotong University, Jiangxi, China
Haijiang Zhang:School of Civil Engineering, Hebei University of Engineering, Hebei, China
Huapeng Chen:Jiangxi Provincial Key Laboratory of Comprehensive Stereoscopic Traffic Information Perception and Fusion, East China, Jiaotong University, Jiangxi, China
Shanhua Xu:School of Civil Engineering, Xi'an University of Architecture & Technology, Xi'an, China
Abstract
As is known, evaluating strength degradation characteristics of rock mass of great importance in civil engineering.
This research is conducted to assess the influence law of disrupt characteristics and confining pressure on the mechanical
characteristics of rock mass. The results show that the strength of rock samples linearly increases with the increase of confining
pressure. The strength reduction rate of rock samples decreases more obviously with the increase of fracture length and quantity,
and the strength effect is most obvious when the confining pressure increases. With the increase of confining pressure, the failure
mode of intact rock samples changes from tension to shear, the rock samples with different lengths/quantities of prefabricated
fractures all undergo shear failure, but as the quantity of fractures increases the rock samples ultimately exhibit a "rhombus"
failure mode. On this basis, a damage constitutive model was established that can reflect the characteristics of the entire
deformation and failure process of fractured rock masses. The model parameters m and F0 can reflect the brittle and strength
characteristics of the rock mass. The stress-strain curve and damage evolution curve of the rock mass have a good
correspondence with the macroscopic failure process induced by its structural changes. The macroscopic defects formed by
prefabricated fractures have a significant impact on the initial damage state of the rock mass, leading to a deterioration of its
mechanical properties. All in all, the research results provide important theoretical basis for the prevention and safety evaluation
of similar fractured rock engineering disasters.
Key Words
damage constitutive model; fractured rock mass; geometric features; strength deterioration; triaxial
compression
Address
Chao Yuan:College of Sciences, Xi'an University of Science and Technology, Xi'an, Shaanxi 710054, China
Huimei Zhang:College of Sciences, Xi'an University of Science and Technology, Xi'an, Shaanxi 710054, China
Shiguan Chen:College of Architecture and Civil Engineering, Xi
