TY - JOUR A1 - Signorini, C. A1 - Bracklow, F. A1 - Hering, Marcus A1 - Butler, M. A1 - Leicht, L. A1 - Schubert, T. A1 - Beigh, M. A. B. A1 - Beckmann, B. A1 - Curbach, M. A1 - Mechtcherine, V. T1 - Ballistic limit and damage assessment of hybrid fibre-reinforced cementitious thin composite plates under impact loading N2 - Impact resistance of reinforced concrete (RC) structures can be significantly improved by strengthening RC members with thin composite layers featuring high damage tolerance. Indeed, to limit the well-known vulnerability of cement-based materials against impact loading, the synergistic effects of short fibres and continuous textile meshes as hybrid reinforcement has been proved to be highly beneficial. This paper addresses the characterisation of novel cement-based hybrid composites through accelerated drop-weight impact tests conducted on rectangular plates at different impact energies. Two distinct matrices are assessed, with particular interest in a newly developed limestone calcined clay cement (LC3)-based formulation. Important parameters quantifying energy dissipation capability, load bearing capacity and damage are cross-checked to compute the ballistic limit and estimate the safety-relevant characteristics of the different composites at hand. Although textiles alone can improve the damage tolerance of fine concrete to some extent, the crack-bridging attitude of short, well-dispersed fibres in hybrid composites imparts a certain ductility to the cement-based matrices, allowing a greater portion of the textile to be activated and significantly reducing the amount of matrix spalling under impact. KW - Impact loading KW - Cement-based composites KW - SHCC KW - TRC KW - Sustainable binders PY - 2023 DO - https://doi.org/10.1016/j.jobe.2023.108037 VL - 80 SP - 1 EP - 21 PB - Elsevier Ltd. AN - OPUS4-58793 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schubert, T. A1 - Bracklow, F. A1 - Unger, N. A1 - Hering, Marcus A1 - Beckmann, B. T1 - Impact Tests on Reinforced Concrete Slabs – Variation in Results and Residual Load Bearing Capacity due to Hard Impact N2 - Structures such as concrete slabs and concrete barriers of critical infrastructure facilities must be able to withstand impact events or severe accidents. In particular, the structural safety of the confinements of nuclear power plants against a possible aircraft impact is essential to ensure the safety of inhabitants and environment. This article presents research results of hard impact on reinforced concrete slabs, which have been carried out at the Institute of Concrete Structures (IMB) at TUD Dresden University of Technology Technische Universität (TU Dresden). A specially designed drop tower is available for this purpose on the premises of the Otto Mohr Laboratory of TU Dresden. In the framework of a research project many reinforced concrete slabs of dimension 1.5 x 1.5 x 0.2 m³ were tested by hard impact. The investigation on some already carried out impact tests on reinforced concrete slabs intend to show the range of deviation of impact tests. In particular, the possible standard deviations that should be regarded in impact tests are estimated for the applied test setup. Furthermore, the residual structural capacity of an undamaged and damaged reinforced concrete slab has been investigated. T2 - Conference: 27th International Conference on Structural Mechanics in Reactor Technology (SMiRT) CY - Yokohama, Japan DA - 04.03.2024 KW - Reinforced Concrete KW - Drop Tower KW - Hard Impact PY - 2024 SP - 1 EP - 10 PB - IASMiRT CY - Yokohama, Japan AN - OPUS4-61915 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hering, Marcus A1 - Sievers, Jürgen A1 - Curbach, Manfred A1 - Beckmann, Birgit T1 - An Approach to Predicting the Ballistic Limit of Thin Textile-Reinforced Concrete Plates Based on Experimental Results N2 - In this article, a partial selection of experiments on enhancing the impact resistance of structural components with non-metallic, textile-reinforced concrete is discussed. The focus is on the experimental investigations in which the impact resistance of thin, textile-reinforced concrete plates is characterized. The article discusses the materials, fabrics and test setup used. For the experimental work, a drop tower from the Otto Mohr Laboratory, which belongs to the Technische Universtät Dresden, was used. Furthermore, the experimental results are presented and evaluated using different methods. Based on the collected data, a suitable approach to determining the perforation velocity of an impactor through the investigated thin, textile-reinforced concrete plates is shown. KW - Building and Construction KW - Civil and Structural Engineering PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-586692 DO - https://doi.org/10.3390/buildings13092234 VL - 13 IS - 9 SP - 1 EP - 14 PB - MDPI AN - OPUS4-58669 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hering, Marcus A1 - Fiedler, Georg T1 - Investigation of multiple impact-damaged reinforced concrete structures as a reference for liquid penetration behavior and tomographic studies N2 - The structural integrity of outer reinforced concrete (RC) containments of nuclear power plants provides an essential shield against external hazards. If this containment is damaged by an impact event, such as an aircraft crash, the question arises to which degree the reinforced concrete containment still has its protective capability. This concerns both purely structural protection and protection against liquids penetrating the interior of the containment. Due to the dimensions of the containment structures, it is difficult to perform real scale impact experiments, so in the past decades plate geometries at medium scale have been used for investigations. Detailed investigations on the structural behaviour of RC members or RC plates subjected to impact loading have already been presented in Just et al., Hering, Hering et al., Bracklow et al., Hille et al. and Nerger et al. The following investigations deal with the single and multiple impact event (first hard impact and/or subsequent soft impact) on a RC specimen, which provides the basis for further investigations. A description of the test setup and the test procedure as well as a presentation of the test results from the impact tests are provided. Furthermore, the experimental program is presented, which the damaged RC specimens are to undergo to deal with the question of how much the impact-damaged RC structure has become permeable to liquid media, such as water and kerosene, depending on the intensity of the impact. The aim of these following investigations is to develop a test setup that can be applied to investigate the liquid penetration behaviour (LPB) of small, medium, and large-scale RC members. In addition to the liquid penetration experiments, the damaged specimens are to be examined by planar tomography to obtain the damage inside the specimen. The combination of damaging event, fluid penetration behaviour and tomography should enable a comprehensive understanding of the damage to the RC specimen. T2 - Conference: 27th International Conference on Structural Mechanics in Reactor Technology (SMiRT) CY - Yokohama, Japan DA - 04.03.2024 KW - Drop Tower KW - Hard Impact KW - Multiple Impact KW - Soft Impact PY - 2024 AN - OPUS4-61991 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hering, Marcus A1 - Fiedler, Georg A1 - Schubert, T. A1 - Hille, Falk A1 - Hüsken, Götz A1 - Beckmann, B. A1 - Grunwald, Marcel A1 - Redmer, Bernhard A1 - Rogge, Andreas T1 - Investigation of multiple impact-damaged reinforced concrete structures as a reference for liquid penetration behavior and tomographic studies N2 - The structural integrity of outer reinforced concrete (RC) containments of nuclear power plants provides an essential shield against external hazards. If this containment is damaged by an impact event, such as an aircraft crash, the question arises to which degree the reinforced concrete containment still has its protective capability. This concerns both purely structural protection and protection against liquids penetrating the interior of the containment. Due to the dimensions of the containment structures, it is difficult to perform real scale impact experiments, so in the past decades plate geometries at medium scale have been used for investigations. Detailed investigations on the structural behaviour of RC members or RC plates subjected to impact loading have already been presented in Just et al., Hering, Hering et al., Bracklow et al., Hille et al. and Nerger et al. The following investigations deal with the single and multiple impact event (first hard impact and/or subsequent soft impact) on a RC specimen, which provides the basis for further investigations. A description of the test setup and the test procedure as well as a presentation of the test results from the impact tests are provided. Furthermore, the experimental program is presented, which the damaged RC specimens are to undergo to deal with the question of how much the impact-damaged RC structure has become permeable to liquid media, such as water and kerosene, depending on the intensity of the impact. The aim of these following investigations is to develop a test setup that can be applied to investigate the liquid penetration behaviour (LPB) of small, medium, and large-scale RC members. In addition to the liquid penetration experiments, the damaged specimens are to be examined by planar tomography to obtain the damage inside the specimen. The combination of damaging event, fluid penetration behaviour and tomography should enable a comprehensive understanding of the damage to the RC specimen. T2 - Conference: 27th International Conference on Structural Mechanics in Reactor Technology (SMiRT) CY - Yokohama, Japan DA - 04.03.2024 KW - Drop tower KW - Hard impact KW - Soft impact KW - Multiple impact PY - 2024 SP - 1 EP - 10 PB - IASMiRT CY - Yokohama, Japan AN - OPUS4-59723 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hering, Marcus A1 - Agasty, Amit A1 - Costard, René A1 - Hüsken, Götz A1 - Chruscicki, Sebastian A1 - Hicke, Konstantin T1 - Explosion effects on reinforced concrete structures – A preliminary study of scaling laws N2 - Blast tests are required to investigate accidental or intentional blast events and to assess the level of protection for people and facilities in critical infrastructures. Conducting large-scale field tests for complex scenarios is very resource intensive. Reliable small-scale experiments are a promising alternative. However, the scaling laws for the design of reinforced concrete structures under blast loads are not sufficiently established. In our research work, a consortium made up of three BAM departments, focuses on reinforced concrete structures that are suitable for the standardization of scaled blast tests. As part of the feasibility study, blast tests were carried out on test specimens of different sizes on the BAM Test Site for Technical Safety (TTS). Various reinforced concrete plates were tested and subjected to different blast loads. The blast tests included various measurement techniques to quantify the blast load and the behavior of the reinforced concrete plate. The blast load was measured with flush-mounted piezoelectric pressure gauges, while accelerometers and embedded fiber optic sensor cables were used to characterize the dynamic behavior of the plate under blast loading. In addition, damage characteristics were also determined using distributed fiber optic sensing. The application of these measurement techniques as well as the use of different numerical software tools offer the possibility to verify or adapt the scaling laws. T2 - 19th International Symposium on Interaction of the Effects of Munitions with Structures (19th ISIEMS) CY - Bonn, Germany DA - 09.12.2024 KW - Scaling KW - Blast KW - Fiber optic sensing PY - 2024 SP - 1 EP - 9 AN - OPUS4-62258 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agasty, Amit A1 - Hering, Marcus T1 - Experimental and Numerical Analysis of Reinforced Concrete Structures Under Blast Loading: Scopes and Challenges N2 - Protection against terrorist or accidental scenarios in industrial settings requires suitable designs of structures to resist blast loads. Field testing as well as finite element simulations are among the techniques available to engineers in the understanding of the structural behavior against blast loading. As blast testing of complex scenarios can be very resource intensive, tests are generally performed for simplified scenarios. Numerical tools can be used to model these scenarios in order to get a better insight into blast loading, structural response and the resulting damage to the structure. In the next steps, the simplified scenario is successively modified in numerical simulations to incorporate complexities that cannot be covered in blast testing experiments. One of the conditions for this approach to work is that the original simplified numerical simulation is valid. The scopes and challenges encountered in such a validation are the focus of this presentation. A relatively ‘simple’ field test of a horizontal reinforced concrete (RC) slab subjected to blast loading is taken as an example for validation of the performance of numerical tools. The blast test incorporated various measurement techniques to quantify the blast load as well as the behavior of the RC slab. Blast load was measured using flush-mounted piezoelectric pressure gauges, whereas acceleration sensors and fiber-optic sensor cables were used to characterize the dynamic behavior of the slab under blast loading. Additionally, damage characteristics were ascertained also using fiber-optic sensing. The application of such measurement techniques, along with different numerical software available for the analysis of the scenario in question, demonstrate the scope of our contribution. T2 - 24th International Physical Security Forum Brussels CY - Brussels, Belgium DA - 15.04.2024 KW - Blast KW - Reinforced Concrete Structures KW - Numerical simulations PY - 2024 AN - OPUS4-60880 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hering, Marcus T1 - Explosion effects on reinforced concrete structures: A preliminary study of scaling laws N2 - Blast tests are required to investigate accidental or intentional blast events and to assess the level of protection for people and facilities in critical infrastructures. Conducting large-scale field tests for complex scenarios is very resource intensive. Reliable small-scale experiments are a promising alternative. However, the scaling laws for the design of reinforced concrete structures under blast loads are not sufficiently established. In our research work, a consortium made up of three BAM departments, focuses on reinforced concrete structures that are suitable for the standardization of scaled blast tests. As part of the feasibility study, blast tests were carried out on test specimens of different sizes on the BAM Test Site for Technical Safety (TTS). Various reinforced concrete plates were tested and subjected to different blast loads. The blast tests included various measurement techniques to quantify the blast load and the behavior of the reinforced concrete plate. The blast load was measured with flush-mounted piezoelectric pressure gauges, while accelerometers and embedded fiber optic sensor cables were used to characterize the dynamic behavior of the plate under blast loading. In addition, damage characteristics were also determined using distributed fiber optic sensing. The application of these measurement techniques as well as the use of different numerical software tools offer the possibility to verify or adapt the scaling laws. T2 - 19th International Symposium on Interaction of the Effects of Munitions with Structures (19th ISIEMS) CY - Bonn, Germany DA - 09.12.2024 KW - Blast KW - Fiber optic sensing KW - Scaling PY - 2024 AN - OPUS4-62260 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schubert, Thomas A1 - Máca, Petr A1 - Hering, Marcus A1 - Fiedler, Georg A1 - Beckmann, Birgit T1 - Impact Experiments on Reinforced Concrete Specimens - Investigation of Repeatability and Scaling N2 - Nowadays, the impact resistance of concrete structures has become a prominent concern for critical infrastructure operators, particularly amidst escalating geopolitical tensions. Regulators and design engineers know that reinforced concrete structures can only be developed with high efficiency by considering nonlinear structural and highly nonlinear material behavior. Therefore, specific guidelines on impact design provide instructions for design and analysis of structures required to resist impact loading. These instructions are usually based on published results and evaluated data of impact experiments carried out in laboratories. To widen the knowledge and increase the scientific data the Institute of Concrete Structures (IMB) at TUD Dresden University of Technology (TUD) has carried out many impact experiments on reinforced concrete specimens in recent years. A specially designed drop tower is available for this purpose on the premises of the Otto Mohr Laboratory, TUD. In the framework of the past research at TUD some important issues, such as influence of rebar arrangement, structural thickness, scalability of specimen and repeatability, with regard to experimental impact testing were investigated. This article presents the drop tower facility and research results of impact experiments on reinforced concrete slabs. First, the scalability of impact experiments will be discussed in conjunction with already known theoretical scaling parameters provided by researchers in the past, e.g. Rüdiger et al. [1]. Scalability of experimental data is of huge importance since protective structures made of reinforced concrete differ usually in size in comparison to experimental specimens. The second important research focus is on repeatably of impact experiments. Since impact experiments are usually time consuming and expensive, a certain impact scenario is mostly carried out only once. It is intended to show the range of deviation of impact tests on some already carried out experiments on reinforced concrete slabs. A possible standard deviation is estimated for the applied test setup. T2 - 15th International Conference on Shock & Impact Loads on Structures CY - Gothenburg, Sweden DA - 12.06.2025 KW - Reinforced concrete KW - Drop-weight impact KW - Scaling KW - Repeatability KW - Digital image correlation PY - 2025 SP - 80 EP - 91 AN - OPUS4-63627 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agasty, Amit A1 - Costard, Rene A1 - Hering, Marcus A1 - Chruscicki, Sebastian A1 - Hicke, Konstantin A1 - Hüsken, Götz T1 - Assessment of the Application of Scaling Concepts for Blast Effects Analysis N2 - Blast testing finds its implementation in several applications, e.g. for the purpose of investigation into accidental or intentional explosions, or for an assessment of the level of protection provided by a certain structural configuration. Analytical and/or semi-empirical methods are generally limited to preliminary assessments prior to blast testing. Applications of numerical simulations with hydrocodes coupled with finite element methods (FEM) can only reduce the amount of blast testing required, as these necessitate fulfillment of the fundamental prerequisites of model verification and that of model validation. Field tests are implemented for contact detonations as well as near-field blast scenarios and shock tube tests for far-field blast scenarios. However, these can be extremely resource intensive. Reliable small-scale experiments are a promising alternative. The concepts of dimensional analysis and similarity based on Buckingham’s Π-theorem (1914) have been applied in different fields. For applications to the phenomenon of shock wave propagation, Hopkinson-Cranz or cube-root scaling is a well-established concept. When it comes to scaling the structural response, research has predominantly focused on structures made of metallic materials. Scaled investigations with concrete or reinforced concrete (RC) structures remain limited. The lack of even the most basic guidelines (far from any ‘standardized scaling methods’ for blast tests) show that scaling as a method is not yet established in blast effects analysis. In this preliminary study, we present a systematic approach and evaluation of scaling of blast effects analysis for RC slabs in order to develop guidelines for resource efficient testing methods. We study the blast scenario at two different scales. The focus of these investigations has been on evaluation of scaling of dynamics using pressure sensors, acceleration sensors and fiber optic sensing cables for distributed acoustic sensing (DAS). Further, the resulting plastic behavior upon blast is characterized by distributed strain sensing (DSS) along the same cables. T2 - 27th International Symposium on Military Aspects of Blast and Shock (MABS27) CY - Colmar, France DA - 06.10.2025 KW - Similarity and scaling KW - Blast KW - RC-slabs PY - 2025 SP - 1 EP - 11 AN - OPUS4-64617 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -