Wyniki wyszukiwania - BazTech

1

Development of Loop-Shaped Textile Anchoring Reinforcements Based on Multiaxial Warp Knitting Technology

Rittner Steffen, Speck Kerstin, Seidel André, Ewertowski Mateusz, Curbach Manfred, Cherif Chokri

Fibres & Textiles in Eastern Europe

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2020

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Vol. 28, no. 6 (144)

64--71

EN

Due to the General Building Approval granted for the strengthening of steel reinforced concrete structures by means of textile reinforced concrete, the foundation for its introduction into practice was successfully established. It approves textile reinforcements in the form of non-crimp fabrics made of carbon fibre heavy tows with high yarn fineness. Thus, it is aimed at increasing the amount of filaments per roving in order to minimise the number of reinforcing layers required. However, the relation between the surface and cross-sectional area is compromised once fineness is increased, leading to an unfavourable enlargement of anchoring and overlapping lengths. Therefore, a recently concluded research project evaluated if this challenge can be overcome by means of a loop-shaped selvedge. This paper presents the results generated within these investigations, proving the potential of the textile-based solution. Moreover, required machine modifications based on multiaxial warp knitting technology for the integral and continuous manufacturing of anchoring textile reinforcements as well as significant results derived from bonding tests will be introduced.

PL

W pracy zaproponowano wzmocnienie konstrukcji żelbetowych za pomocą betonu zbrojonego materiałem tekstylnym w postaci tkanin wykonanych z włókien węglowych. Celem pracy było zwiększenie ilości włókien przypadających na niedoprzęd, tak aby zminimalizować liczbę wymaganych warstw wzmacniających. Jednak kompromisowa zależność między powierzchnią a polem przekroju jest zagrożona po zwiększeniu grubości, co prowadzi do niekorzystnego zwiększenia zakotwienia i zachodzenia na siebie długości. Dlatego niedawno zakończony projekt badawczy miał na celu ocenę, czy to wyzwanie można pokonać za pomocą krajki w kształcie pętli. W artykule przedstawiono wyniki uzyskane w ramach tych badań, które potwierdziły potencjał rozwiązania tekstylnego. Ponadto w wyniku przeprowadzonych badań wprowadzono wymagane modyfikacje maszyn w oparciu o technologię wieloosiowego dziania osnowowego do integralnego i ciągłego wytwarzania tekstylnych wzmocnień kotwiących.

2

Flexural and shear behavior of reinforced concrete beams strengthened with carbon textile reinforced concrete

Nguyen H. C., Ngo D. Q.

Archives of Civil Engineering

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2020

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Vol. 66, nr 3

407--426

EN

Recently, textile reinforced concrete (TRC) has been intensively studied for strengthening reinforced concrete (RC) and masonry structures. This study is to experimentally explore the effectiveness of application of carbon TRC to strengthen RC beam in flexure and shear. Concerning the cracks formation, failure modes, ultimate strength and overall stiffness, the performance of the strengthened beams compared to the control beams were evaluated from two groups of tests. The test results confirm that the TRC layers significantly enhance both shear and flexural capacity of RC beams in cracking, yielding and ultimate loads. All of the tested specimens were also modelled using ABAQUS/CAE software, in order to validate the experimental results. The numerical results show that the simulation models have good adaptability and high accuracy.

3

Experimental and analytical investigation on strengthening of heat damaged concrete by textile reinforced concrete (TRC)

Esmaeili J., Sharifi I., Kasaei J., Nourizadeh M., Emamieh A. Ebrahim

Archives of Civil and Mechanical Engineering

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2019

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Vol. 19, no. 4

1468--1483

EN

Composites fabricated of textile as reinforcement and a fine-grained concrete as matrix are referred to textile reinforced concrete (TRC) which provides the opportunity to build thin and shell constructions and to repair and strengthen concrete and masonry structures. This paper aimed to exploit the repair potential of TRC through confinement of heat-damaged concrete columns. For this purpose, a two-phase approach was conducted, in the first phase of which the effect of elevated temperature on mechanical properties of concrete was examined. The main objective of the second phase, however, was to assess the efficiency of glass textile reinforced concrete (GTRC) in the confinement of heat-damaged concrete. This phase commenced with selecting a candidate mortar among commonly used TRC mortars to confine heat-damaged specimens. Experimental results revealed that the adopted confinement system is an efficient solution to enhance the load bearing capacity of even seriously heat-damaged specimens. Eventually, experimental results were compared with available prediction models from the literature for both of the load-bearing capacity and also the compressive strength of confined concrete. Then an analytical confinement model was proposed based on best-fit analysis exclusive to heat-damaged concrete confined by GTRC.

4

Beton zbrojony tkaniną - od badań do zastosowania

Orlowsky J., Raupach M.

Cement Wapno Beton

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2011

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R. 16/78, nr 6

323-331

PL

Od jedenastu lat w dwóch niemieckich uniwersytetach prowadzone są badania nad zastosowaniem tkanin technicznych w inżynierii lądowej. Te tkaniny zastępują konwencjonalne zbrojenie w betonach lub w zaprawach. Wielkość przenoszonych obciążeń przez elementy konstrukcyjne z betonu zbrojonego tkaniną są takie same jak zbrojonych betonów konwencjonalnych. Oprócz swobody w stosowanych rozwiązaniach konstrukcyjnych związanych z tkaninami, szczególnie cienkościenne konstrukcje stanowią zaletę nowego betonu zbrojonego tkaninami. W oparciu o znajomość tego kompozytu zdobytą w trakcie badań w uniwersyteckich ośrodkach, betony zbrojone tkaninami są stosowane coraz częściej w nowych konstrukcjach, a także do odnowienia i konserwacji starszych budowli. Oprócz kładek dla pieszych i elementów fasadowych wykonanych z betonu zbrojonego tkaninami, czasami dodatkowo z izolacją cieplną w centrum uwagi jest wykorzystanie tych zapraw i betonów w formie warstw wzmacniających lub do zapraw tradycyjnego żelbetu.

EN

For the past eleven years, studies at two German universities have been devoted to the use of technical textiles in civil engineering. These textiles are used instead of conventional steel reinforcement for concretes or mortars. The load bearning capacity of textile reinforced concrete elements is equal to that of conventionally reinforced concrete elements. Besides the fl exibility in construction arising from the simple design of the textiles, especially the thin-walled structure of textile reinforced concrete elements is an outstanding advantage of the new composite material, textile reinforced concrete. Based on the building material knowledge gained at the universities, textile reinforced concretes have increasingly been applied in new constructions as well as in building conservation. In addition to footbridges and self-supporting facade elements made of textile reinforced concrete, optionally with integrated thermal insulation, the application of textile reinforced mortar or concrete layers to reinforce or repair steel reinforced concrete elements is in the focus.