scholarly journals A new testing method for textile reinforced concrete under impact load

2018 ◽  
Vol 199 ◽  
pp. 11010 ◽  
Author(s):  
Marcus Hering ◽  
Manfred Curbach
Keyword(s):  
Reinforced Concrete ◽  
Large Scale ◽  
Impact Load ◽  
Impact Resistance ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Impact Loads ◽  
Textile Reinforced Concrete ◽  
Reinforcement Structure ◽  
Testing Method

Textile reinforced concrete, especially textile reinforced concrete with carbon fibres, was already been used for strengthening steel reinforced concrete structures under static loads up to now. The question is if the composite can also be used for strengthening structures against impact loads. The main goal of a current research project at the Technische Universität Dresden is the development and characterization of a reinforcement fabric with optimized impact resistance. But there is a challenge. There is the need to find the best combination of fibre material (glass, carbon, steel, basalt, …) and reinforcement structure (short fibres, 2D-fabrics, 3D-fabrics, …), but testing the large number of possible combinations is not possible with the established methods. In general, large-scale tests are necessary which are very expensive and time consuming. Therefore, a new testing method has been developed to deal with this large number of possible combinations of material and structural experiments. The following paper describes this new testing method to find the best fabric reinforcement for strengthening reinforced concrete structures against impact loads. The testing devise, which is located in the drop tower facility at the Otto Mohr Laboratory, and the test set-up are illustrated and described. The measurement equipment and the methods to evaluate the experimental results are explained in detail.

Improving the Impact Resistance of Reinforced Concrete

2014 ◽  
Vol 919-921 ◽  
pp. 1924-1929 ◽  
Author(s):  
Husain Abbas ◽  
Tarek Almusallam ◽  
Yousef Al-Salloum
Keyword(s):  
Reinforced Concrete ◽  
Split Hopkinson Pressure Bar ◽  
Impact Resistance ◽  
Concrete Structures ◽  
Material Behavior ◽  
Analytical Models ◽  
Impact Loads ◽  
Hopkinson Pressure Bar ◽  
Hybrid Fibers ◽  
The Impact

The strategic concrete structures are often required to resist impact loads arising from the projectile strike, falling weight, blast generated missile etc. The existing structures found deficient in resisting these loads are required to be retrofitted whereas the upcoming structures are required to be designed for expected impact loads. This paper explores the ways of strengthening existing reinforced concrete (RC) structures using externally bonded carbon fiber reinforced polymer (CFRP) sheets and improving the impact resistance of concrete by mixing hybrid fibers in its production. The impact response of concrete structures is assessed using experiments involving the impact of projectiles of different nose shapes on slab specimens. The material behavior at high strain rate is established using split Hopkinson pressure bar (SHPB) testing at varying strain rates. Analytical models are developed for predicting penetration depth, scabbing thickness, ballistic limit velocity and ejected mass. The experimental results were also validated through numerical modeling using LS-DYNA.

Laboratory Tests and Numerical Simulations of CFRP Strengthened RC Pier Subjected to Barge Impact Load

2015 ◽  
Vol 15 (02) ◽  
pp. 1450037 ◽  
Author(s):  
Yanyan Sha ◽  
Hong Hao
Keyword(s):  
Reinforced Concrete ◽  
Structural Damage ◽  
Impact Load ◽  
Numerical Models ◽  
Impact Resistance ◽  
Bridge Piers ◽  
Impact Loads ◽  
Bridge Structures ◽  
Cfrp Composite ◽  
Vessel Impact

Bridge piers are designed to withstand not only axial loads of superstructures and passing vehicles but also out-of-plane loads such as earthquake excitations and vessel impact loads. Vessel impact on bridge piers can lead to substantial damages or even collapse of bridge structures. An increasing number of vessel collision accidents have been reported in the past decade. A lot of researches have been conducted for predicting barge impact loads and calculating structural responses. However, in practice it is not possible to design bridge structures to resist all levels of barge impact loads. Moreover, with an increasing traffic volume and vessel payload in some waterways, the bridge piers designed according to previous specifications might not be sufficient to resist the current vessel impact loads. Therefore, strengthening existing bridge piers are sometimes necessary for protecting structures from barge impact. Carbon fiber reinforced polymer (CFRP) has been widely used in strengthening reinforced concrete structures under impulsive loadings. It is an effective material which has been proven to be able to increase the flexural strength of structures. In this study, CFRP composites are used to strengthen reinforced concrete piers against barge impact loads. Pendulum impact tests are conducted on scaled pier models. Impact force and pier response with and without CFRP strengthening are compared. The effectiveness of using CFRP strengthening the pier model is observed. In addition, numerical models of the bridge piers are developed and calibrated with experimental results. Parametric simulations of barge impacting on piers with or without CFRP strengthening are carried out. The results show that compared with unstrengthened pier, CFRP composite strengthened bridge pier has a higher impact resistance capacity and hence endures less structural damage under the same barge impact load. The effectiveness of CFRP strengthening with different CFRP thickness, CFRP strength and bond strength between the pier and the CFRP composite are also discussed.

scholarly journals Self-Healing of Cracked Textile Reinforced Concrete Layers

Proceedings ◽  
2019 ◽  
Vol 34 (1) ◽  
pp. 20
Author(s):  
Lenting ◽  
Orlowsky
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Self Healing ◽  
Textile Reinforced Concrete ◽  
Steel Reinforced Concrete ◽  
Material Development ◽  
Inorganic Coating ◽  
Protection Layer ◽  
Crack Widths

Sustainable maintenance of existing steel-reinforced concrete structures becomes more important. Using non-reinforced sprayed mortar to maintain these structures often leads to cracks in this repair layer due to the alteration of crack widths in the ordinary structure. The water impermeability as well as the durability of the sprayed mortar will be reduced due to the described cracks. This presentation shows a solution for the described problem. The use of carbon yarns with a special inorganic coating as reinforcement in sprayed mortars leads to a self-healing of the arising cracks. Due to the inorganic coating applied on carbon yarns the excellent bond between mortar and yarn results in a fine distributed crack image with crack width below 0.1 mm. It is shown that these cracks heal themselves. Consequently we can provide a mainly mineral protection layer for existing steel reinforced concrete structures which is impermeably to water based solutions. The presentation focuses on the material development and characterization.

Optimierte Formen aus Textilbeton am Beispiel der Grillmöbel „Donauwelle“/Optimized shapes for textile reinforced concrete structures – design of the barbecue furniture “Donauwelle”

Bauingenieur ◽  
2016 ◽  
Vol 91 (10) ◽  
pp. 425-433
Author(s):  
Martin Ritt ◽  
Benjamin Kromoser
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Textile Reinforced Concrete

Um dem ständig steigenden Bedarf an natürlichen Ressourcen und der zunehmenden Umweltverschmutzung entgegenwirken zu können, sind neue Lösungen im Bauwesen unumgänglich. Eine mögliche Herangehensweise ist die Erweiterung des Anwendungsgebietes von Beton durch Einsatz von textiler Bewehrung. Textile Bewehrung ist sehr feingliedrig und nicht rostend was eine deutliche Reduktion der erforderlichen Betondeckung möglich macht. Durch die leichtere Konstruktionsweise kann ein bedeutender Anteil des Baumaterials eingespart und zur Reduktion der erforderlichen Ressourcen beigetragen werden. Mit dem Beitrag „Donauwelle“ konnten die Autoren den von der MA 45 der Stadt Wien und der Vereinigung der Österreichischen Zementindustrie ausgeschriebenen Wettbewerb zur Neumöblierung der Wiener Donauinsel gewinnen. Mittlerweile wurde der Entwurf von der Stadt Wien bereits mehrfach realisiert. Im ersten Teil des vorliegenden Aufsatzes wird der Formfindungs- und Entwurfsprozess genauer beschrieben. Im zweiten Teil des Beitrags wird auf die durchgeführten Versuche, das Nachweiskonzept, die Bemessung und die Herstellung eingegangen.

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