Finite element investigation of the influence of fiber orientation on the pullout behavior of rebar embedded in
2 Investigations
As first experimental campaign investigations of UHPFRC spraying process, material properties and bond behaviour have been conducted.
Shotcreted UHFPRC specimens were analysed by means of magnetic resonance imaging (MRI) scans. This provided a plausible statement on load-bearing behaviour due to the internal steel fibre orientation. In addition, quantities of rebound material are determined and the spray shadow behind reinforcement layers is visually examined. The interface of the hardened composite is analysed by digital reflected light microscopy.
The material properties of the ultra-high performance shotcrete are assessed based on the guidelines for conventional shotcrete. Tests have been carried out to determine the modulus of elasticity and the stress-strain behaviour in compression and tension both axially and orthogonally to the applied spraying direction.
Furthermore, the adhesive bond to the existing concrete was examined. For this investigation, tensile bond tests and symmetric push-out tests were carried out for determining the adhesive tensile strength and the shear load bearing behaviour, respectively.
174 3 Selected Results
The UHPFRC is highly suitable for application as shotcrete. Spraying of the ultra-high performance concrete was realised in cooperation with the industrial partners LafargeHolcim and Implenia Instandsetzungs GmbH (see Figure 1). Due to the specific rheology of the ultra-high performance concrete, there are complex demands on the processing technology. The optimisation of the material and workability was a major aspect of the investigation.
Figure 2 and 3 exemplary show first
results as a part of the experimental campaign: tensile and compressive stress-strain curves.
First material tests have shown a compressive strength of about 130 MPa (tests on cylinders and cubes), tensile strength up to 6 MPa with strain hardening behaviour (axial tensile test) and
a Young’s
modulus from 35 GPa to 40 GPa.
Thus, the obtained UHPFRC concrete is highly suitable for strengthening and conform to UHPFRC require-ments [2].
4 Conclusions
The pumpability and sprayability has been proved by the test campaign. Application of the material as shotcrete is highly suitable.
The first testing of the UHPFRC shows excellent material properties and the feasibility of application with high-performance but conventional construction machinery.
The material properties correspond to the intended material behaviour. Based on the observed material properties, further investigations and optimisations regarding material technology will be carried out. A detailed consideration of the time-depending material properties will be investigated.
As next step in the research program, fields of application are investigated in cooperation with stakeholders and owners of damaged structures (e.g. building authorities). After this, investigation regarding structural design and durability will be carried out.
References
[1] Bundesanstalt für Straßenwesen (BASt), „Verstärkungen älterer Beton- und Spannbetonbrücken,“
2016.
[2] R. Bornemann, M. Schmidt, E. Fehling und B. Middendorf, „UHPC Herstellung, Eigenschaften und Anwendungsmöglichkeiten,“ Beton- und Stahlbetonbau Heft 7, 2001.
Figure 3: Compressive strength
Figure 1: UHPFRC spraying
Figure 2: Tensile strength
List of Authors
175
List of Authors
A. Gopal, Balamurugan 11
Abd Elrahman, Mohamed 23
Abellan, Joaquin 43, 97
Aboubakr, Attitou 131
Abrishambaf, Amin 37
Akanshu, Sharma 155
Alrashidi, Raid S. 31
Alvarado, Yezid 153
Andersson, Louise 1, 77
André, Ludovic 41
Anido, Roberto Lopez 91
Asgedom, Miliyon Yohans 75
Bader, Tobias 55
Batista Ruiz, Carmen Maria 73
Bernard, Florian 41
Bertrand, Jean 41
Beßling, Markus 19
Bilgin, Serdar 51
Billo, Joel 81
Boher, Cédric 41
Boiron, Laurent 133
Brander, Linus 99
Brindley, Gilbert S. 85
Brühwiler, Eugen 109
Buriot, Eric 41
Caerels, Pieter 157
Camacho, Esteban 135, 165
Carrazedo, Ricardo 159
Cauberg, Niki 45
Choi, Hong-Joon 71
Chun, Booki 71
Chung, Sang-Yeop 23
Citek, Adam 47
Citek, David 47
Coll, Hugo 135, 165
Courard, Luc 49
Cwirzen, Andrzej 77
Damtoft, Jesper Sand 73
Dauberschmidt, Christoph 149, 161, 173
de Miranda Saleme Gidrão, Gustavo 159
Delameilleure, Iben 157
Derimay, Julien 81
176
Dinkler, Dieter 141
Domingues, Aline Bensi 147
Dreßler, Inka 27
Eden, Wolfgang 101
Eichler, Hannes 59, 171
El Debs, Mounir Khalil 147
El Madawy, Mohamed 23
Empelmann, Martin 15, 67, 83, 141
Fehling, Ekkehard 13, 59, 129, 131, 171
Fernandez, Jaime 97
Fischer, Oliver 119, 121
Flansbjer, Mathias 99
Fontana, Patrick 51
Fourré, Marlène 81
Franssen, Renaud Jean 49
Galán, Fernando 135, 165
Gehlen, Christoph 27, 33, 61
Göbel, Daniela 105
Grünewald, Steffen 127
Gruyaert, Elke 157
Guirado, Franck 81
Hafezolghorani, Milad 11
Hammerl, Mathias 17
Heard, William F. 3
Heimdal, Anette 139
Hejazi, Farzad 11
Hendrix, Douglas R. 63
Hofmann, Jan 155
Hong, Sung-Gul 29, 53
Höper, Svenja 141
Hoppe, Johannes 51
Hordijk, Dick 127
Hurtado, Jeisson 153
Huß, Michael 5, 117, 137
Ilg, Manuel 65
Jang, Yun-Sik 71
Javidmehr, Sara 67
Jayananda, Nikhil 127
Jung, Myungjun 53
Jungwirth, Jörg 161, 173
Kang, Sung-Hoon 79
Kim, Hoang Huy 5, 117, 137
Kim, Min-Jae 145
List of Authors
177
Kolisko, Jiri 47
Kothari, Ankit 77
Kowalsky, Ursula 141
Krahl, Pablo Augusto 147, 159
Kränkel, Thomas 27, 33, 61
Kromoser, Benjamin 17
Krystov, Martin 47
Kumar, Dhanendra 3
Kustermann, Andrea 149, 161, 173
Kusumawardaningsih, Yuliarti 13, 131
Kytzia, Susanne 103
Lackner, Roman 55
Landis, Eric 91
Langer, Mathias 49
Lanwer, Jan-Paul 141
Larsen, Ingrid Lande 139
Le, Hoang Thanh Nam 95
Lechner, Thomas 119, 121
Lehmann, Christian 87
Leutbecher, Torsten 9
Lion, Maxime 81
Lohaus, Ludger 107, 111
López, Juan Ángel 135, 165
Lorenz, Paul 129
Lowke, Dirk 27
Marek, Jan 47
Matthäus, Carla 61
Matz, Henrik 15
Maurer, Marco 133
Mayer, Michael 117
Meglin, Ronny 103
Meng, Birgit 51, 87, 151
Metje, Kevin 9
Middendorf, Bernhard 25, 57, 69, 101, 105
Mihaylov, Boyan 49
Milad, Hafezolghorani 125
Minne, Peter 157
Mladena, Luković 127
Mokhberdoran, Paria 143
Moon, Juhyuk 79
Mueller, Urs 21, 99
Nguyen, Duc Tung 93
Nguyen, Tue Viet 5, 93, 117, 137
178
Nicot, Pierre 81
Nielsen, Erik Pram 73
Nunes, Sandra 37, 143
Nuñez, Andres 43, 97, 153
Ocampo, Manuel 153
Ochmann, Carmen 19
Oettel, Vincent 67, 141
O'Flaherty, Tomas 35
Orlowsky, Jeanette 19
Otto, Corinne 107
Pahn, Matthias 39
Park, Ji-Seul 29
Perry, Vic H. 115
Piérard, Julie 45
Pimentel, Mário 37, 143
Plank, Johann 65
Poh, Leong-Hien 95
Pollner, Toni 149, 173
Pons, Tony 81
Prieto, Miguel 99
Rabade, Miguel Prieto 21
Ragalwar, Ketan A. 3
Rai, Bijaya 7
Ranade, Ravi 3
Reece, Jerry W. 85
Renaud, Jean-Claude 81
Riding, Kyle Austin 31
Roosen, Marco 127
Roy, Manish 169
Ruiz, Daniel 153
Rushing, Todd 91
Samuel, Arango 43
Sarah Voss, Megan 31
Schade, Tim 101
Scheydt, Jennifer C. 123
Schleiting, Maximilian 69
Schmidt, Markus 173
Schmitt, Nicolas 81
Schöne, Stefan 123
Schramm, Nicholas 119, 121
Schultz-Cornelius, Milan 39
Seibert, Peter J. 85, 115
Shen, Xiujiang 109
List of Authors
179
Shin, Wonsik 71, 145
Sikora, Pawel 23
Silva, Nelson 1, 77
Simon, Alain 81
Sine, Aurélio 143
Singh, Nashatra Bahadur 75
Siqueira, Gustavo Henruque 159
Smarzewski, Piotr 163
Smith Gillis, Reagan 91
Stephan, Dietmar 23, 87
Strotmann, Andre 161, 173
Stuerwald, Simone 103
Suchorzewski, Jan 21
Tan, Jhen Shen 125
Tej, Petr 47
Terrade, Benjamin 81
Thiedeitz, Mareike 27
Thiemicke, Jenny 59, 131, 171
Thorstensen, Rein Terje 139
Tian, Hongwei 87
Tomann, Christoph 111
Torres, Nancy 97
Toumi, Ahmed 41
Toutlemonde, Francois 81
Turatsinze, Anaclet 41
Ulfkjær, Jens Peder 113
Ulzurrun, Gonzalo S.D. 89
Umbach, Cristin 25
Vacca, Hermes 153
van der Zee, Pieter 45
Vandenberg, Aileen C. 167
Vertes, Katalin 139
Vidal, Thierry 41, 81
Vita, Norbert 155
Voigt, Marieke 87, 151
Vojvodic, Goran 5, 93
Vollmar, Roland 59, 171
von Werder, Julia 51, 151
Voo, Yen Lei 11, 125
Wachter, Lisa 123
Wang, Shasha 95
Weger, Daniel 33, 61
Wetzel, Alexander 25, 57, 69, 105