Experimental and numerical investigations on the impact resistance of SHCC-strengthened RC slabs subjected to drop weight loading

2019 ◽  
Vol 229 ◽  
pp. 116866 ◽  
Author(s):  
Amira B. Elnagar ◽  
Hamdy M. Afefy ◽  
Ahmed T. Baraghith ◽  
Mohamed H. Mahmoud
Keyword(s):  
Impact Resistance ◽  
Numerical Investigations ◽  
Drop Weight ◽  
Rc Slabs ◽  
The Impact ◽  
Weight Loading

Experimental and Numerical Study of Basalt FRP Strip Strengthened RC Slabs under Impact Loads

2020 ◽  
Vol 20 (06) ◽  
pp. 2040001 ◽  
Author(s):  
Wensu Chen ◽  
Thong M. Pham ◽  
Mohamed Elchalakani ◽  
Huawei Li ◽  
Hong Hao ◽  
...  
Keyword(s):  
Failure Modes ◽  
Shear Failure ◽  
Numerical Study ◽  
Impact Resistance ◽  
Basalt Fiber ◽  
Impact Behavior ◽  
Impact Loads ◽  
Quantitative Measurements ◽  
Rc Slabs ◽  
The Impact

Basalt fiber-reinforced polymer (BFRP) has been applied for strengthening concrete structures. However, studies on reinforced concrete (RC) slabs strengthened by BFRP strips under impact loads are limited in open literature. This study investigates the efficiency of using BFRP strips with various strengthening layouts and anchoring schemes on the impact resistance of RC slabs. A total of 11 two-way square slabs were prepared and tested, including one reference specimen without strengthening and ten slabs strengthened with BFRP strips and/or anchors. The RC slabs were impacted by a drop weight with increasing height until slab failure. The observed failure modes include punching shear failure, BFRP sheet debonding and reinforcement fracture. The failure modes and the effects of using various strengthening schemes on the impact resistant capacity of RC slabs were examined. The quantitative measurements, such as impact velocity, indentation depth and diameter, were compared and discussed. In addition, numerical studies were carried out by using LS-DYNA to simulate the impact tests of RC slabs with and without BFRP strengthening. With the calibrated numerical model, the impact behavior of slabs with various dimensions and strengthening layouts under different impact intensities can be predicted with good accuracy.

scholarly journals Experimental Investigation on the Impact Resistance of Carbon Fibers Reinforced Coral Concrete

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4000 ◽  
Author(s):  
Bing Liu ◽  
Jingkai Zhou ◽  
Xiaoyan Wen ◽  
Jianhua Guo ◽  
Xuanyu Zhang ◽  
...  
Keyword(s):  
Weibull Distribution ◽  
Carbon Fibers ◽  
Impact Test ◽  
Concrete Strength ◽  
Impact Resistance ◽  
Initial Crack ◽  
Drop Weight ◽  
Weight Impact ◽  
The Impact ◽  
Two Parameter

In this study, the impact resistance of coral concrete with different carbon fiber (CF) dosages subjected to drop-weight impact test was investigated. For this purpose, three concrete strength grades (C20, C30, C40) and six CF dosages (0.0%, 0.3%, 0.6%, 1.0%, 1.5%, and 2.0% by weight of the binder) were considered, and a total of 18 groups of carbon fibers reinforced coral concrete (CFRCC) were cast. For each group, eight specimens were tested following the drop-weight impact test suggested by CECS 13. Then, the two-parameter Weibull distribution theory was adopted to statistically analyze the variations in experimental results. The results indicated that the addition of CFs could transform the failure pattern from obvious brittleness to relatively good ductility and improve the impact resistance of coral concrete. Moreover, the impact resistance of CFRCC increases with the CF dosage increasing. The statistical analysis showed that the probability distribution of the blow numbers at the initial crack and final failure of CFRCC approximately follows the two-parameter Weibull distribution.

Impact resistance of Nomex honeycomb sandwich structures with thin fibre reinforced polymer facesheets

2016 ◽  
Vol 20 (5) ◽  
pp. 531-552 ◽  
Author(s):  
Longquan Liu ◽  
Han Feng ◽  
Huaqing Tang ◽  
Zhongwei Guan
Keyword(s):  
Finite Element ◽  
Impact Energy ◽  
Sandwich Structures ◽  
Impact Resistance ◽  
Impact Response ◽  
Woven Fabric ◽  
Drop Weight ◽  
Honeycomb Sandwich ◽  
Nomex Honeycomb ◽  
The Impact

In order to investigate the impact resistance of the Nomex honeycomb sandwich structures skinned with thin fibre reinforced woven fabric composites, both drop-weight experimental work and meso-mechanical finite element modelling were conducted and the corresponding output was compared. Drop-weight impact tests with different impact parameters, including impact energy, impactor mass and facesheets, were carried out on Nomex honeycomb-cored sandwich structures. It was found that the impact resistance and the penetration depth of the Nomex honeycomb sandwich structures were significantly influenced by the impact energy. However, for impact energies that cause full perforation, the impact resistance is characterized with almost the same initial stiffness and peak force. The impactor mass has little influence on the impact response and the perforation force is primarily dependent on the thickness of the facesheet, which generally varies linearly with it. In the numerical simulation, a comprehensive finite element model was developed which considers all the constituent materials of the Nomex honeycomb, i.e. aramid paper, phenolic resin, and the micro-structure of the honeycomb wall. The model was validated against the corresponding experimental results and then further applied to study the effects of various impact angles on the response of the honeycomb. It was found that both the impact resistance and the perforation depth are significantly influenced by the impact angle. The former increases with the obliquity, while the latter decreases with it. The orientation of the Nomex core has little effect on the impact response, while the angle between the impact direction and the fibre direction of the facesheets has a great influence on the impact response.

Relationship between Impact Energy and Flexural Toughness Energy of Steel Fiber Reinforced Lightweight Aggregate Concrete

2011 ◽  
Vol 261-263 ◽  
pp. 385-388
Author(s):  
Hai Tao Wang ◽  
Jin Qing Jia
Keyword(s):  
Impact Energy ◽  
Impact Resistance ◽  
Lightweight Aggregate ◽  
Steel Fibers ◽  
Lightweight Aggregate Concrete ◽  
Aggregate Concrete ◽  
Flexural Toughness ◽  
Drop Weight ◽  
Flexural Tests ◽  
The Impact

In order to determine the impact resistance of lightweight aggregate concrete (LWC), especially the effect of steel fibers on impact resistance of LWC, a series of drop-weight tests, recommended by the ACI committee 544, have been carried out in the present study. Impact and flexural tests were carried out on lightweight aggregate concrete reinforced with five different percentages of steel fibers 0.0%, 0.5%, 1.0%, 1.5% and 2.0% by volume of concrete. For each volume of fibers, complete load–deflection curves of SFLWC were generated in order to determine the total energy absorbed for each specimen. The addition of steel fibers to concrete has improved impact resistance and also the flexural toughness. The test results showed that a logarithmic relation exists between flexural toughness energy by means of the generated load–deflection curves from the flexural tests and the impact energy by means of drop-weight tests.

Effectiveness of hybrid-fibers in improving the impact resistance of RC slabs

2015 ◽  
Vol 81 ◽  
pp. 61-73 ◽  
Author(s):  
Tarek H. Almusallam ◽  
Aref A. Abadel ◽  
Yousef A. Al-Salloum ◽  
Nadeem A. Siddiqui ◽  
Husain Abbas
Keyword(s):  
Impact Resistance ◽  
Hybrid Fibers ◽  
Rc Slabs ◽  
The Impact

Experimental Investigation on Impact Ductility of Polymer-Modified Concrete Subjected to Falling Weight Loading

2014 ◽  
Vol 1030-1032 ◽  
pp. 770-773 ◽  
Author(s):  
Xiao Hui Guo ◽  
Xin Le Zhang ◽  
Hai Cao
Keyword(s):  
Experimental Investigation ◽  
Impact Resistance ◽  
Plain Concrete ◽  
Test Results ◽  
Cement Ratio ◽  
Polymer Modified Concrete ◽  
Falling Weight ◽  
The Impact ◽  
Impact Ductility ◽  
Weight Loading

The impact ductility of plain concrete and polymer-modified concrete with different p-c (polymer-cement) ratio were measured by bend-impact method. The impact-resistance of plain concrete and polymer-modified concrete were contrasted. The modified mechanism of polymer-modified concrete was analyzed. The results indicate that the impact ductility of concrete are increased with contents of polymer firstly and then reduced and the best p-c ratio is 15%. The test results also indicate that the concrete performance are modified by polymer, which prevent crack developing in microcosmic and improve impact ductility in macroscopic.

Dynamic Response of 3D-Printed Bi-Material Structure Using Drop Weight Impact Test

2017 ◽  
Author(s):  
Anish Ravindra Amin ◽  
Yi-Tang Kao ◽  
Bruce L. Tai ◽  
Jyhwen Wang
Keyword(s):  
Energy Absorption ◽  
Impact Test ◽  
Impact Resistance ◽  
Silicone Elastomer ◽  
Material Structure ◽  
Pu Foam ◽  
Drop Weight ◽  
3D Printed ◽  
Weight Impact ◽  
The Impact

Additive manufacturing has led to increasing number of applications that require complex geometries and multiple materials. This paper presented a bi-material structure (BMS) composed of a cushion matrix held by a 3D printed frame structure for an improved impact resistance. The study mainly focused on understanding the effects of structural topology and matrix material. Two matrix materials, silicone elastomer and polyurethane (PU) foam, were selected to impregnate into two different PLA frame structures. Drop weight impact test was carried out to measure the impact force and energy absorption. The results showed that the overall impact resistance was dominated by the frame, while the matrix reinforcement required proper structural interlocking mechanism and material matching. In the particular specimens of this study, PU foam led to more energy absorption and force bearing capacity of the structure than the silicone elastomer.

Impact and static behavior of strain-hardening cementitious composites–strengthened reinforced concrete slabs

2020 ◽  
Vol 23 (8) ◽  
pp. 1614-1628 ◽  
Author(s):  
Mohamed H Mahmoud ◽  
Hamdy M Afefy ◽  
Ahmed T Baraghith ◽  
Amira B Elnagar
Keyword(s):  
Reinforced Concrete ◽  
Thin Layer ◽  
Strain Hardening ◽  
Human Life ◽  
Impact Resistance ◽  
Concrete Slabs ◽  
Cementitious Composites ◽  
Reinforced Concrete Slabs ◽  
Drop Weight ◽  
The Impact

Impact loading could impair the entire structure or a part of it, thus making the human life at stake. In this study, to improve the impact resistance of reinforced concrete slabs under drop-weight loading, a thin layer of strain-hardening cementitious composites was added at either tension or compression side of the slab. The main parameter of this study was the three contact surface conditions, namely grinding, grinding plus steel dowels, and grinding plus epoxy adhesive, between the substrate slab and the strain-hardening cementitious composites layer. Therefore, 63 reinforced concrete slabs were prepared and tested under the effect of drop-weight falling from three different heights: 1, 1.5, and 2 m. In addition, for comparison purposes, additional seven slabs were tested under central incremental static loading until failure is presented. It was found that the strain-hardening cementitious composites–strengthening layer enhanced the impact and static response of the strengthened slabs when added at either tension or compression side. Besides, to achieve the outermost impact resistance showing ductile performance, it is better to provide a thin layer of the strain-hardening cementitious composites at the tension side of the slab connected to the substrate slab by epoxy resin applied on pre-prepared grinded surface.

scholarly journals Researchon Impact Resistance of Fibre Reinforced Concrete

2019 ◽  
Vol 8 (6S4) ◽  
Keyword(s):  
Reinforced Concrete ◽  
Impact Test ◽  
Impact Resistance ◽  
Steel Fibers ◽  
Fibre Reinforced Concrete ◽  
Drop Weight ◽  
Weight Test ◽  
Drop Weight Test ◽  
The Impact

in this exam, an undertaking is needed to bear in mind the impact restriction of fiber bolstered concrete. on this exam, a easy, rational and reasonable drop weight test become finished on fiber invigorated cement as indicated with the resource of ACI board 544. Fibers containing steel, polypropylene, sisal have been used because the invigorating in four unmistakable quantity components, for instance, 0%,0.five%,1%,1.five%. The results validated that developing the quantity part of fiber prolonged the impact deterrent of sturdy version stood out from customary bond. The outcomes moreover shown that steel fibers are greater dominant at extending the impact test than severa strands.

scholarly journals Evaluation of Impact Resistance for Derailment Containment Provision Using Drop Weight Test

2020 ◽  
Vol 20 (5) ◽  
pp. 185-194
Author(s):  
NamHyuk Kim ◽  
YunSuk Kang ◽  
HyunUng Bae ◽  
KyungJu Kim ◽  
NamHyoung Lim
Keyword(s):  
High Speed ◽  
Impact Resistance ◽  
Impact Behavior ◽  
Human Errors ◽  
Railway Bridges ◽  
Drop Weight ◽  
Weight Test ◽  
Drop Weight Test ◽  
Protective Performance ◽  
The Impact

In Korea, to prepare for unexpected accidents caused by human errors and natural disasters that cannot be completely prevented, a protective wall (a type of side-structure) against derailed trains has been installed on high-speed railway bridges as one of the physical measures to mitigate the associated damage. However, taking the geometric aspects of a domestic railway bridge's super structure into consideration, such a protective wall is not appropriate, and the corresponding protective performance does not provide adequate security. Hence, a protective wall named Derailment Containment Provision (DCP) was newly developed and installed in the track gauge. In this study, to evaluate the impact resistance of the newly developed DCP, a drop weight experiment was conducted, and the impact behavior corresponding to a specific impact energy was analyzed.

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