Reinforced Concrete Plates under Impact Load—Damage Quantification

Abstract

A large number of impact experiments have been carried out at the Technische Universität Dresden in recent years in several research projects. The focus was on reinforced concrete plates on the one hand and on subsequently strengthened reinforced concrete plates on the other hand. Based on these investigations, two fundamental tasks arose: (1) finding an objective description of the damage of components made of steel reinforced concrete that had previously been subjected to an impact load and (2) quantification of the effect of a subsequently applied strengthening layer. In this paper we will focus on both. At first, the experimental conditions and program as well as the used drop tower facility at the Otto Mohr Laboratory of the Technische Universität Dresden are briefly explained. In the summary presentation of the main test results, the focus is on the observed component damage. Based on the observations, an approach for a damage description is presented. To define global damage, the stiffness of the investigated structural components before and after the impact event is used. At the end of the paper, the potential of the method, but also gaps in knowledge and research needs are discussed.

Tensile Behavior of High-Strength, Strain-Hardening Cement-Based Composites (HS-SHCC) Reinforced with Continuous Textile Made of Ultra-High-Molecular-Weight Polyethylene

“…TRC, also termed textile reinforced mortar (TRM), consists of fine-grained, cementitious matrices reinforced by continuous two- or three-dimensional textile meshes, usually made of carbon or glass multifilament yarns, and exhibits ductile, strain-hardening tensile behavior [ 9 , 10 , 11 , 12 ]. With regard to cyclic and highly dynamic loading, the geometric configuration of typical 2D and 3D textile reinforcements is not sufficiently fine to ensure dense crack patterns and high energy dissipation capacity, without substantial fragmentation and spalling of the cementitious matrix [ 13 ]. The latter can be mitigated by the addition of short, dispersed fibers.…”

“…It has also been shown that the mechanical properties and coating of the textile reinforcement define to a large extent the tensile strength and the pre-peak deformability of the hybrid fiber-reinforced composites under investigation. The carbon textile exhibits high tensile strength and stiffness, both of which are essential for the strong confinement of the RC elements, both under quasi-static and severe dynamic loading [ 1 , 13 ]. However, the strain capacity of typical HS-SHCC is potentially higher compared to that of carbon yarns [ 26 ].…”

Influences on the structural response of beams in drop tower experiments

“…In the experiments described in subsequent studies, [9][10][11] which were also carried out at low impactor velocities, the formation of inclined shear cracks was the main failure criterion. Bangash 1 and Hering et al 6 distinguished between local and global damage in higher velocity impact scenarios. Local damage includes scabbing at the top and spalling at the bottom of the structural member.…”

“…On a large observation scale, a lot of different plate experiments were carried out by different researchers. Information on these experiments can be found for example in subsequent studies 5–8 . Besides plate tests, drop tower beam tests were often performed.…”

Computational Micro-Macro Analysis of Impact on Strain-Hardening Cementitious Composites (SHCC) Including Microscopic Inertia

“…Furthermore, the sound upscaling and application of the meso-level findings in the structural design involving SHCC should be supported by adequate numerical scale-linking models. This is due to the fact that the assessment and discrimination of various structural effects as inertia phenomena and complex fracture-mechanical mechanisms is hardly possible based on structural tests alone (see [6][7][8]). Multiscale methods represent a powerful tool to link the mesoscale and structural scale within the corresponding composite material.…”