Volumetric strain behaviour and self-healing of large scale engineered cementitious composite and normal concrete panels under natural conditions

2021 ◽  
Vol 308 ◽  
pp. 125078
Author(s):  
Ahmad Hooshmand ◽  
Reza Kianoush ◽  
Hocine Siad ◽  
Mohamed Lachemi ◽  
Emad Booya ◽  
...  
2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Muhammad Aswin ◽  
Bashar S. Mohammed ◽  
M. S. Liew ◽  
Zubair Imam Syed

Reinforced concrete dapped-end beams (RC-DEBs) are mainly used for precast element construction. RC-DEBs generally are recessed at their end parts and supported by columns, cantilevers, inverted T-beams, or corbels. The geometric discontinuity of dapped-end beams evokes a severe stress concentration at reentrant corners that may lead to shear failure. Therefore, stress analysis is required at the reentrant vicinity for design requirement of these beams. Four large-scale RC-DEBs specimens were prepared, cast, and tested up to failure. Three parameters were investigated: amount of nib reinforcements, main flexural reinforcements, and concrete type at the dapped-end area. Finite element analysis using Vec2 was also conducted to predict the behavior of RC-DEBs. It has been found that highest stresses concentration factors occur at the reentrant corners and its vicinity. By using engineered cementitious composite (ECC) in the dapped-end area, the failure load has increased by 51.9%, while the increment in the failure load was 62.2% and 46.7% as the amount of nib reinforcement and main flexural reinforcement increased, respectively. In addition, Vec2 analysis has been found to provide better accuracy for predicting the failure load of RC-DEBs compared to other analysis approaches.


2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Bashar S. Mohammed ◽  
M. F. Nuruddin ◽  
Muhammad Aswin ◽  
Nursyuhada Mahamood ◽  
Hashem Al-Mattarneh

Eight large-scale reinforced self-compacted engineered cementitious composite (R-SC-ECC) beams with different steel reinforcement ratios have been designed, prepared, cast, cured, and tested to failure at the age of 28 days. The experimental results have been compared with theoretical values predicted using EC2, RILEM, and VecTor2 models. Results show that failure modes in flexure and shear of R-SC-ECC beams are comparable to that of normal reinforced concrete beam. Nevertheless, contrary to VecTor2, models of EC2 and RILEM are not suitable for predicting reasonable ultimate moments for the beams, while results using VecTor2 model have successfully predicted the failure modes and load-deflection curves for all R-SC-ECC beams. It has been concluded that R-SC-ECC fall in the category of ductility class medium to high which gives advantages of using R-SC-ECC beams in regions susceptible to seismic activities.


Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2609
Author(s):  
Zhiqing Zhu ◽  
Guojin Tan ◽  
Weiguang Zhang ◽  
Chunli Wu

Engineered cementitious composite (ECC) is a potential cement-based material with the abilities of large deformation and crack width control. However, ECC is difficult to popularize in many developing countries because the costs of silica sand and polyvinyl alcohol (PVA) fiber with a surface coating are too high for practical engineering. Therefore, we proposed an economical ECC with superfine river sand and polypropylene (PP) fiber (SSPP-ECC) to replace PVA fiber and silica sand. The SSPP-ECC proposed in this paper is a sustainable material using local material ingredients, which has considerable adaptability for large-scale engineering applications. The 16 groups of specimens were prepared through a factorial design method, curing for four-point bending tests. The bending strength, deflection, flexural modulus of elasticity, and crack width were measured and calculated during the test. The factor analysis of the test results shows that the contents of fiber and fly ash had significant effects on the ductility of SSPP-ECC with an extra combined effect at the same time, and a response surface model with high accuracy was fitted to predict the yield length of SSPP-ECC. The ductility of SSPP-ECC was positively related to its crack-control ability and it was shown that the crack width of SSPP-ECC increased significantly with a high content of superfine sand. This paper proposed a reasonable way to utilize superfine sand and provided the mix proportion of SSPP-ECC with characteristics of deformation hardening and multi-cracking, which may cater to the demands of many concrete components on ductility and crack resistance.


2012 ◽  
Vol 450-451 ◽  
pp. 433-438
Author(s):  
Phillip Hermes ◽  
Yi Xia Zhang ◽  
Khin Soe ◽  
Joel Bell

A new hybrid-fiber Engineered Cementitious Composite (ECC) containing 1.25% steel (SE) fibers and 0.75% Polyvinyl Alcohol (PVA) fibers is proposed, and material properties of the new ECC mix are tested in this paper. The compressive strength, modulus of elasticity, modulus of rupture and tensile properties under various strain rates of the new hybrid-ECC mix are investigated experimentally. The tested results are compared with those for a normal concrete mix, as well as those for other mono-fiber and hybrid-fiber ECCs reported in other literatures.


2004 ◽  
Vol 41 (2) ◽  
pp. 227-241 ◽  
Author(s):  
Jorge G Zornberg ◽  
Alexandre R Cabral ◽  
Chardphoom Viratjandr

Tire shreds and tire shred – soil mixtures can be used as alternative backfill material in many geotechnical applications. The reuse of tire shreds may not only address growing environmental and economic concerns, but also help solve geotechnical problems associated with low soil shear strength. In this study, an experimental testing program was undertaken using a large-scale triaxial apparatus with the goal of evaluating the optimum dosage and aspect ratio of tire shreds within granular fills. The effects on shear strength of varying confining pressure and sand matrix relative density were also evaluated. The tire shred content and tire shred aspect ratio were found to influence the stress–strain and volumetric strain behaviour of the mixture. The axial strain at failure was found to increase with increasing tire shred content. Except for specimens of pure tire shreds and with comparatively high tire shred content, the test results showed a dilatant behaviour and a well-defined peak shear strength. The optimum tire shred content (i.e., the one leading to the maximum shear strength) was approximately 35%. For a given tire shred content, increasing the tire shred aspect ratio led to increasing overall shear strength, at least for the range of tire shred aspect ratios considered in this study. The shear strength improvement induced by tire shred inclusions was found to be sensitive to the applied confining pressure, with larger shear strength gains obtained under comparatively low confinement.Key words: tire shreds, shear strength, reinforcement, triaxial testing, stress–strain behaviour.


2016 ◽  
Vol 860 ◽  
pp. 125-134 ◽  
Author(s):  
Abla Krouma ◽  
Zubair Imam Syed

Engineered Cementitious Composite (ECC) is a material with high ductility, tensile strength and self-healing more than the standard concrete. Applications of ECC are beneficial due to its long life cycle, high strength, low cost in the long-term, low maintenance and environmentally friendly nature. Properties and hardened behavior of ECC highlights that ECC has a tight crack width development, which increases its ability to resist long-term effects of hot, frost and humid weather. Additionally, it results low water permeability coefficient and high steel corrosion resistance compared to other common alternative materials. One of the promising areas of application for ECC is in highway structures, especially highway bridges. Highway structures suffer constantly from adverse environmental loads and often require frequent repairing or replacing due to cracks; expansion; water and chlorides effects which cause steel corrosion or the slope between the pavement, slab and the support at the end of a bridge. Detailed review on different properties and characteristics of ECC and the current applications of ECC clearly highlights the motivation to enhance the use of ECC for bridge construction. In addition, ECC can be introduced in jointless bridges by putting an ECC link slab instead of the expandable mechanical joint.


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