Subject matter

The development of textile reinforced concrete (TRC) field has generated tremendous interest in the international scientific community and several research groups in the field [1,2 ,3 ,4 ,5]. TRC materials are lightweight, ductile, strong, and have the potential to be used as structural components taking tensile, cyclic and impact loads. The advancements in the textile technology specifically directed at the use in cement based materials has also led to composites with an order of magnitude higher in strength and two orders of magnitude higher in ductility than conventional fiber reinforced concrete (FRC). The TRC are increasingly being developed using innovative fabrics, matrices and innovative manufacturing processes.

Led by the RILEM leadership, several previous committees have addressed TRC materials in the past 14 years. The first TRC committee was formed in July 2002, the RILEM TC 201-TRC (Textile Reinforced Concrete) [6,7]. The work of this committee was followed by a second committee Technical Committee 232-TDT addressing Test methods and design of textile reinforced concrete, led by Professor Wolfgang Brameshuber in between 2009 to 2014. This is a new proposal to ask for formation of a new RILEM Committee on Textile Reinforced Concrete (TRC) materials to address Analysis and Design with TRC materials. One major item is the cooperation with ACI 549 – Thin concrete elements, where similar topics are also addressed. The proposed TC will continue the work in recommendations of test methods and work out a manual for design of the composites. At the beginning, the state-of-the-art-report will be updated, and the results of a round robin test conducted earlier will be incorporated in the new work plan towards the development of design tools and guides. The expected outcomes include the develop a set of recommendations and design manual [8].

Fabric reinforced cement composites constitute a recent addition to the family of cement based composite materials. Various research groups have developed a wealth of recent information pertaining the methodologies, properties, and areas of applications for fabric reinforced cement based materials [9,10,11,12,]. The theoretical framework will address aspects of multi-scale modeling, analytical tools to predict and design components for tensile, flexural, and shear loading of TRC composite systems [13,14, 15]. The range of applications are expected to address classes of strain hardening composites that exhibit distributed cracking mechanisms and will cover materials such as textile reinforced [1], ferrocement [16], Glass fiber reinforced concrete [17], UHPFRC [18], HPFRC [19]. Development of design models for strain hardening cement composites for structural applications requires ductility based design guidelines to predict tensile, flexural, and shear strength. The proposed approaches may be based on conventional engineering design tools used in the building codes and include structural analysis codes, limit analysis, plastic analysis, and allowable stress based design procedures.

The main objective of high ductility designs is based on using a rational serviceability based approach. Applications include highly ductile fatigue and impact resistance, industrial structures, and transportation structure components. In these systems post-cracking stress capacity extends over a large strain range using a reduced stiffness parameter. Unlike cases that address fracture localization, crack propagation that is resisted by fiber bridging requires substantial energy for extension, hence secondary cracks form and for a structurally indeterminate system with multiple crack paths form hinge mechanisms in the context of limit analysis. Design procedures are therefore based on multiple distributed cracking mechanisms and macroscopic pseudo-strain hardening behaviors [20,21,22].

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1. Proceedings pro075 : International RILEM Conference on Material Science - 2nd ICTRC - Textile Reinforced Concrete - Theme 1, Edited by W. Brameshuber, ISBN: 978-2-35158-106-3 e-ISBN: 978-2-35158-107-0 Pages: 374, Publication date: 2010
2. SP-251CD: Design & Applications of Textile-Reinforced Concrete, SP251CD Editor: Corina-Maria Aldea Sponsored by: ACI Committee 549, 2008
3. Report 36: Textile Reinforced Concrete - State-of-the-Art Report of RILEM TC . 2006
4. SP-250CD: Textile Reinforced Concrete, Editor: Ashish Dubey, ACI Committee 549, Vol: 250, 2008, ACI SP Special Publication Volume: 250
5. Kruger, M. Ozbolt, J., and Reinhardt, H.W., "A New 3D Discrete Bond Model to Study The Influence of Bond on Structural Performance of Thin Reinforced and Prestressed Concrete Plates", Proc., 4th Int. RILEM Workshop on High Performance Fiber Reinforced Cement Composites (HPFRCC4), Eds. A.E., Naaman and H.W., Reindhart, Ann Arbor, 2003, pp. 49-63.
6. Brameshuber, W., Koster, M., Hegger, J., Voss. S., Gries, T. , Barle, M., Reinhardt, H.-W., Krüger, M., : Textile Reinforced Concrete (TRC) for Integrated Formworks. In: 12. Internationale Techtextil-Symposium für technische Textilien, Vliesstoffe und textilarmierte Werkstoffe. . Messe Frankfurt GmbH, 07.04.03-10.04.03, Frankfurt. Frankfurt: 2003, 4.23. - CD-Rom
7. Kruger, M. Ozbolt, J., and Reinhardt, H.W., "A New 3D Discrete Bond Model to Study The Influence of Bond on Structural Performance of Thin Reinforced and Prestressed Concrete Plates", Proceeding of the Fourth International RILEM Workshop on High Performance Fiber Reinforced Cement Composites (HPFRCC4), Eds. A.E., Naaman and H.W., Reindhart, Ann Arbor, 2003, pp. 49-63.
8. Kolloquium zu textilbewehrten Tragwerken - 6th Colloquium on Textile Reinforced Structures (CTRS6), 2011, Berlin
9. Meyer C., and Vilkner G., "Glass Concrete Thin Sheets Prestressed with Aramid Fiber Mesh" Proceeding of the Fourth International RILEM Workshop on High Performance Fiber Reinforced Cement Composites (HPFRCC4), Eds. A.E., Naaman and H.W., Reindhart, Ann Arbor, 2003, pp. 325-336.
10. Brameshuber, W., Brockmann, T., Hegger, J., Molter, M., Textilbeton - Betontechnologie und Tragverhalten, Untersuchungen zum Textilbewehrten Beton, Beton 09/2002, Seiten 424-429, (2002).
11. Jesse, F.; Curbach, M.: A new approach for determining geometrical properties of glass fibre reinforcement in grc composites. In: di Prisco, M.; Felicetti, R,; Plizzari, G. A.. (Hrsg.): Fibre-Reinforced Concretes: Proceedings of the "Sixth International RILEM-Symposium - BEFIB 2004", Varenna, 20.-22.9.2004. Bagneux : RILEM, 2004, S. 267-278.
12. Peled, A. and Mobasher, B.,”Pultruded Fabric-Cement Composites,” ACI Materials Journal, Vol. 102 , No. 1, pp. 15-23, 2005.
13. Soranakom, C., and Mobasher B., Design Flexural Analysis and Design of Textile Reinforced Concrete Textile Reinforced Structures : Proceedings of the 4nd Colloquium on Textile Reinforced Structures (CTRS4) und zur 1. Anwendertagung, SFB 528, Technische Universität Dresden, Eigenverlag, 2009, ISBN 978-3-86780-122-5, pp. 273-288.
14. Peled, A., Bentur, A., and Mobasher, B., Textile Reinforced Concrete, CRC press, 2016
15. Mobasher, B., Barsby, C., “Flexural Design Of Strain Hardening Cement Composites”, Proceedings 2nd International RILEM Conference on Strain Hardening Cementitious Composites, (SHCC2-Rio)”,2012 Rio de Janeiro, Brazil, pp. 53-60.
16. Naaman, A.E., and Shah, S.P., “Tensile Test of Ferrocement,” J Amer Concrete Inst, V.68, No.9, Sept. 1971, pp. 693-698.
17. Marikunte S., Aldea, C., and Shah, S.P., “Durability of Glass Fiber Reinforced Cement Composites: Effect of Silica Fume and Metakaolin,” Elsevier Science, 1997, No.5, pp.100-108.
18. Kim, D-J., Naaman, A.E. and El-Tawil, S. (2010), Correlation between Tensile and Bending Behavior of FRC Composites with Scale Effect,Proceedings of FraMCoS-7, 7^th International Conference on Fracture Mechanics of Concrete and Concrete Structures, May 23-28, 2010, Jeju Island, South Korea
19. Mobasher, B., Mechanics of Fiber and Textile Reinforced Cement Composites, Taylor and Francis Group, CRC press, Sept, 2011, 471 pp.
20. Hawkins, N., and Mitchell, D., 1979, “Progressive Collapse of Flat Plate Structures,” ACI JOURNAL, Proceedings 76, No. 7, July, pp. 755-808.
21. Sasani, M., and Sagiroglu, S., 2008, “Progressive Collapse of Reinforced Concrete Structures: A Multihazard Perspective,” ACI Structural Journal, V. 105, No. 1, Jan.-Feb., pp. 96-103.
22. Udilovich, K.; Shleykov, I.; and Banchuzhnyy, M. V., 2010, “Design of Flat-Plate Floors for Progressive Collapse Using Yield-Line Analysis,” Concrete International, V. 32, No. 7, July, pp. 37.

Terms of reference

Proposed outcomes and technical reports of this committee will be communicated among the members using publications, reports, computational tools, and software. The following discussions address the various aspects of the proposed efforts:

1. A review of material models that take into account the tension softening and tension stiffening effect for TRC materials to address ductility-durability-serviceability measures. The STAR report will address various areas of research need and failure mechanisms and the interaction of various failure modes that need to be addressed and integrated into the design protocol.
2. Integration of Testing, analysis, and design procedures to use material models in structural analysis software. Both material and structural design can then be concurrently addressed. Analytical or numerical solution strategies are instrumental in design and analysis of composite systems such as beams, slabs, walls, and buried structures.
3. Solutions for sustainable development of infrastructure systems using blended cements, thermal energy considerations of concrete buildings, repair of existing structures, blast, impact, and high ductility required designs, use of natural fibers, and statistical process control will be showcased.

Detailed working programme

- Literature survey and topical presentations
During each meeting, literature survey and associated presentations shall be planned. Subsequent literature will be also collected by members of the TC.
- State-of-the-art report
The results of the literature survey will be compiled in a state-of-the-art report. The results of the recent TC report will be integrated in to the design procedures to address various design aspects in which areas the members are involved.
- Recommendation
At the end of the evaluation and discussion of various test procedures, recommended practices will be prepared for standardized manuals. The recommendations shall be submitted for publication in Materials & Structures.
- Workshop
Several symposia and workshops are planned for presentation of the TC´s work and discussion of the recommended practices. It is hoped that other experts who are not member of the TC will contribute to the conferences planned. The
proceedings of the conferences shall be prepared, and possibly be published as the special issue of Materials & Structures.
- Literature (please see the references section)
-Previous meetings: During the last two years we have hosted two meetings in order to establish this new technical committee on TRC:
- Meeting at TU Dresden, September 17th, 2017 from 10:00 to 16:00 at the TU Dresden, Germany
- Meeting at Desenzano del Garda, July 27th, 2018 from 10:00 to 16:00 at the hotel Acquaviva del Garda in Italy.
From the meetings 5 working groups were created  :
WG 1 – Materials and material systems
WG 2 – Constitutive modeling
WG 3 – New Elements
WG 4 - Retrofitting
WG 5 – Durability and sustainability