This work investigates potential engineering benefits of the pioneering application of simply extruded recycled high-density polyethylene (HDPE) plastic fibres in structural concrete. Mechanical and serviceability properties of concrete are studied through the testing of seven series of specimens: one made of the plain concrete and, for each of the two fibre diameters Ø 1 = 0.25 mm and Ø 2 = 0.40 mm, three series with 0.40%, 0.75% and 1.25% volume fraction of fibres. While the compressive strength and the elastic modulus of concrete were unaffected, the tensile strength and flexural (rupture) modulus were marginally increased, between 3% and 14% in the presence of HDPE fibres. Fibres mainly contributed by providing the post-cracking flexural ductility and through improving serviceability properties of concrete such as the reduced plastic shrinkage cracking, drying shrinkage and water permeability. The durability of HDPE fibres was assessed by means of the scanning electron microscope (SEM) imaging that showed no signs of their chemical deterioration in concrete. All findings suggest that recycled HDPE fibres can be instrumental in creating a new value chain in construction industry while also positively contributing to its environmental performance.
full bibliographic details are credited, a hyperlink and/or URL is given for the original metadata page and the content is not changed in any way. A note on versions:The version presented here may differ from the published version or, version of record, if you wish to cite this item you are advised to consult the publisher's version. Please see the 'permanent WRAP url' above for details on accessing the published version and note that access may require a subscription.For more information, please contact the WRAP Team at: publications@warwick.ac.uk This paper has been published under the following reference: Pešić, N., Živanović, S., Experimental and finite element dynamic analysis of incrementally loaded reinforced concrete structures. Engineering Structures, Vol. 103, pp. 15-27, doi:10.1016/j.engstruct.2015 ABSTRACTThis work investigates influence of damage in reinforced concrete (RC) structures on their dynamic properties through modal testing and non-linear finite element (FE) analysis. Five RC beams were designed with the fundamental flexural mode frequencies in the range of 6.5-18.0Hz for the uncracked state. Mechanical properties of concrete, such as static and dynamic elastic moduli were determined from standard tests and ultra-sonic pulse velocity readings.The beams were incrementally loaded until the span/250 deflection limit was reached and their natural frequencies were measured from the free decay vibrations. The progressive damage reduced fundamental frequencies of tested beams by up to 25%. The non-linear FE analysis was carried out for RC beams and one two-span slab and the calculated reduced frequencies of the 1st and 2nd vibration modes were in excellent agreement with measurements. This led to the conclusion that, given that the non-linear analysis can capture degradation of dynamic stiffness due to cracking, the future dynamic performance and damage identification on the RC structure can be reliably determined from the same FE model. The results reveal potential of the combined modal testing and FE analysis to improve inspection and assessment of the inservice RC structures.Keywords: Concrete; Modal testing; FE analysis; Structural dynamics; Damage assessment This paper has been published under the following reference: Pešić, N., Živanović, S., Experimental and finite element dynamic analysis of incrementally loaded reinforced concrete structures.
This paper studies the problem of early concrete cover delamination and plate-end failure of reinforced concrete beams strengthened with externally bonded FRP-reinforcement. The accuracy of analytical models and finite element (FE) methods for predicting this type of failure is assessed against published experimental data. Two design approaches based on the maximum concrete tensile strength and the shear capacity of concrete beams were examined first and it was found that linear elastic analysis can not accurately predict the brittle plate-end. It was also found that the extent of strengthening that can be achieved is limited by the shear capacity of concrete beams. The FE analysis is used to examine the effects of internal tensile reinforcement on the magnitude principal tensile stresses in the critical region. The non-linear behaviour of FRP-strengthened beams is also examined in the FE analysis using the smeared crack model for concrete which is shown to adequately display the inelastic deformation of the beam. Finally, the mixed mode of failure due to the combined shear and concrete cover delamination is addressed through modelling plate-end and shear crack discontinuities using the discrete crack approach.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.