scholarly journals Behavior of Short Columns Constructed using Engineered Cementitious Composites under Seismic Loads

2021 ◽  
Author(s):  
Syed Humayun Basha ◽  
Xiaoqin Lian ◽  
Wei Hou ◽  
Pandeng Zheng ◽  
Zi-Xiong Guo
Keyword(s):  
Finite Element ◽  
Response Strength ◽  
Shear Behavior ◽  
Cementitious Composites ◽  
Transverse Reinforcement ◽  
Engineered Cementitious Composites ◽  
Conventional Concrete ◽  
Shear Span ◽  
Short Columns ◽  
Strength And Stiffness

Abstract The present research reports the application of engineered cementitious composites (ECC) as an alternative to conventional concrete to improve the brittle shear behavior of short columns. Experimental and finite element investigation was conducted by testing five reinforced engineered cementitious composite (RECC) concrete columns (half-scale specimens) and one control reinforced concrete (RC) specimen for different shear-span and transverse reinforcement ratios under cyclic lateral loads. RECC specimens with higher shear-span and transverse reinforcement ratios demonstrated a significant effect on the column shear behavior by improving ductility (>5), energy dissipation capacity (1.2 to 4.1 times RC specimen), gradual strength degradation (ultimate drift >3.4%), and altering the failure mode. The self-confinement effect of ECC fibers maintained the integrity in the post-peak region and reserved the transmission of stress through fibers without noticeable degradation in strength. Finite element modelling of RECC specimens was carried out by adopting simplified constitutive material models. It was apprehended that the model simulated the global response (strength and stiffness) with an accuracy of about 95%, and captured the shear and flexure crack patterns reasonably well.

Finite Element Analysis of Shear Strength of Reinforced Concrete Beams after Fire

2013 ◽  
Vol 671-674 ◽  
pp. 474-478 ◽  
Author(s):  
Kai Xiang ◽  
Guo Hui Wang ◽  
Bi Zhao
Keyword(s):  
Finite Element ◽  
Shear Strength ◽  
Reinforced Concrete ◽  
Exposure Time ◽  
Concrete Strength ◽  
Reinforced Concrete Beams ◽  
Rc Beams ◽  
Fire Exposure ◽  
Shear Span ◽  
Strength And Stiffness

Shear strength and stiffness of fire-damaged reinforced concrete (RC) beams were researched. The nonlinear finite element method (FEM) was developed to simulate shear strength of fire-damaged RC beams. Considering mechanical properties deterioration of concrete and steel reinforcing bar, the parameters of fire-damaged RC beams, including fire exposure time, shear span to depth ratios, concrete strength, diameters of stirrups and spacing of stirrups, were analyzed. Based on numerical analysis, the change of shear strength and stiffness of fire-damaged RC beams were identified. The results showed that shear strength and stiffness of fire-damaged RC beams changed under different parameters. With increase of fire exposure time or increase of shear span to depth ratio or decrease of concrete strength, shear strength and stiffness of fire-damaged RC beams descended obviously. With decrease of diameters of stirrups or increase of spacing of stirrups, shear strength of fire-damaged RC beams descended gradually, but stiffness of fire-damaged RC beams had little change.

Confinement of rectangular columns made with engineered cementitious composites (ECC)

2020 ◽  
Vol 47 (11) ◽  
pp. 1215-1225
Author(s):  
Wai Man Wong ◽  
Carlos A. Cruz-Noguez ◽  
Mohammad J. Tolou-Kian
Keyword(s):  
High Performance ◽  
Compressive Load ◽  
High Strength ◽  
Longitudinal Direction ◽  
Strength Loss ◽  
Cementitious Composites ◽  
Stress Strain ◽  
Engineered Cementitious Composites ◽  
Conventional Concrete ◽  
Strain Behavior

Engineered cementitious composites (ECC) is a type of high-performance fiber-reinforced cementitious composites (HPFRCC) designed to achieve high tensile strain capacity with strain hardening effect during the post-cracking response. Previous studies show that ECC has high damage-tolerance capacity in tension, increasing the durability, safety, and sustainability of structures susceptible to cracking and spalling under moderate to severe loading. Under compression, however, there is a lack of data regarding confinement effects on steel-reinforced ECC (RECC) members. Thus, designing ECC structures is usually done by assuming the ECC behaves in the same way as conventional concrete under compression. With scarce experimental data available, this assumption may be inaccurate, uneconomical, or even unsafe. An experimental test program on confined ECC columns was performed in this study. Sixteen 100 mm × 100 mm × 300 mm ECC square columns, consisting of one set of unconfined ECC and three sets of confined ECC with 1%, 1.5%, and 2% transverse steel content were fabricated and tested under monotonic compressive load until failure. The force–displacement and stress–strain relationships in the longitudinal direction were measured. The results show that confined ECC has a compressive stress–strain behavior similar to that of confined high-strength concrete, with a rapid compressive strength loss after peak strength, and a gradual loss of strength that is inversely proportional to the amount of steel reinforcement. An empirical stress–strain model for rectangularly confined high-strength ECC was developed based on an existing model for high-strength conventional concrete.

scholarly journals Investigation of the Mechanical, Microstructure and 3D Fractal Analysis of Nanocalcite-Modified Environmentally Friendly and Sustainable Cementitious Composites

Buildings ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 36
Author(s):  
Mahmoud Ziada ◽  
Yosra Tammam ◽  
Savaş Erdem ◽  
Roberto Alonso González Lezcano
Keyword(s):  
Mechanical Properties ◽  
Fractal Analysis ◽  
Design Theory ◽  
Environmentally Friendly ◽  
Material Design ◽  
Pulse Velocity ◽  
Cementitious Composites ◽  
Microstructural Properties ◽  
Engineered Cementitious Composites ◽  
Conventional Concrete

Unlike conventional concrete materials, Engineered Cementitious Composites (ECC) use a micromechanics-based design theory in the material design process. Recently, the use of nanoparticles in various concretes and mortars has increased. This study used nanocalcite to investigate the mechanical, microstructural fractal analysis of environmentally friendly nanocalcite-doped ECC (NCa-ECC). This paper investigated the effects of nanocalcite (NCa) with different contents (0.5, 1, and 1.5% by mass of binder) on the mechanical properties of engineered cementitious composites (ECC). For this purpose, compressive strength, ultrasonic pulse velocity (UPV), and flexural strength tests were conducted to investigate the mechanical properties of the ECC series. In addition, SEM analyses were carried out to investigate the microstructural properties of the ECC series. The content of nanocalcite improved the mechanical and microstructural properties of the nanocalcite-modified ECC series. In addition, the 1 NCa series (1% nanocalcite modified to the mass of the binder) had the best performance among the series used in this study.

Numerical modeling on varying patch repair size of cracked beam using engineered cementitious composites

2020 ◽  
Vol 18 (1) ◽  
pp. 14-22
Author(s):  
Martyana Dwi Cahyati ◽  
Wei-Hsing Huang ◽  
Hsieh-Lung Hsu
Keyword(s):  
Tensile Strength ◽  
Patch Repair ◽  
Poly Vinyl Alcohol ◽  
Cementitious Composites ◽  
High Tensile Strength ◽  
Cracked Beam ◽  
Engineered Cementitious Composites ◽  
Conventional Concrete ◽  
Content Type ◽  
Concrete Damage

Purpose This study aims to investigate the size effect of the patched repairing material applied to the cracked beam. Design/methodology/approach Numerical analysis was conducted on a simply supported cracked beam with a dimension of 200 × 25 × 15 cm using ABAQUS software. The behavior of concrete and engineered cementitious composites (ECC) in the simulation are described as concrete damage plasticity model. Linear elastic-plastic model was used to represent the behavior of rebar steel. The type of patching consisted of the varying ratio of lengths and depths, including patching length to total length ratios of 0.2, 0.3 and 0.4, and patching depth to total depth ratios of 0.2, 0.3, 0.4 and 0.5. Findings Results show that variations in the patching length and depth ratios affect the maximum flexural load, stiffness and ductility of the repaired beam. It was also found that repairing the cracked beam by using ECC provides higher flexural load of the beam than the use of conventional concrete, owing to the superior tensile strength of ECC. Originality/value ECC is the cementitious-based mortar that contains the special selected poly vinyl alcohol fiber having high tensile strength. ECC has been known to exhibit high ductility, high tensile strength and improve durability performance. Thus, ECC is suitable as repairing material for patching cracked beam. By investigating the size of the patched repairing material applied to the cracked beam, the structural performance of repairing beam and the effectiveness of the various patching size were achieved.

scholarly journals On the shear behavior of engineered cementitious composites

1994 ◽  
Vol 1 (3) ◽  
pp. 142-149 ◽  
Author(s):  
Victor C. Li ◽  
Dhanada K. Mishra ◽  
Antoine E. Naaman ◽  
James K. Wight ◽  
James M. LaFave ◽  
...  
Keyword(s):  
Shear Behavior ◽  
Cementitious Composites ◽  
Engineered Cementitious Composites
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