scholarly journals Impact Resistance of High-Performance Steel Fiber Concrete under Long Term Exposure to Environmental Conditions

2018 ◽  
Vol 206 ◽  
pp. 02007
Author(s):  
Abdulhameed Umar Abubakar ◽  
Tulin Akçaoğlu ◽  
Khaled Marar
Keyword(s):  
Environmental Conditions ◽  
High Performance ◽  
Impact Load ◽  
Impact Resistance ◽  
Plain Concrete ◽  
Fiber Volume ◽  
Steel Fiber Concrete ◽  
Impact Energies ◽  
The Impact

An investigation is presented here that studied the influence of long-term environmental conditions exposure on cylindrical specimens after initial 28 day moist curing. The specimens were tested after six months subjected to Mediterranean weather elements in North Cyprus. Specimens with 150 mm diameter by 60 mm long cylinders were tested under impact load using a modified version of the testing equipment described in ACI 544.2R. Numbers of blows to create first and damage cracks were determined, and subsequently the impact energies calculated. It was seen that there is as much as twenty times improvement in impact energy of fibered concretes at fiber volume of 2% when compared with plain concrete. This will goa long way to improve the impact resistance of industrial floors and slabs on grade.

scholarly journals The comparison of projectile impact resistance of ultra-high-performance fibre-reinforced concrete with various aggregates

2021 ◽  
Vol 250 ◽  
pp. 06007
Author(s):  
Martina Drdlová ◽  
Martin Šperl
Keyword(s):  
Reinforced Concrete ◽  
High Speed ◽  
High Performance ◽  
Structural Integrity ◽  
Impact Load ◽  
Impact Resistance ◽  
Fibre Reinforced Concrete ◽  
Projectile Impact ◽  
The Impact ◽  
High Performance Fibre

In order to apply the ultra-high-performance fibre-reinforced concrete (UHPFRC) in the constructions of ballistic protective structures, the impact resistance of UHPFRC has been investigated experimentally by conducting the high-speed projectile penetration tests. 5 mixtures with basalt and corundum aggregates with various grain size have been prepared and subjected to the quasi-static and 7.62 x 54R B32 API projectile impact load using the striking velocity of 850 m/s. The influence of the strength, size and material of the aggregate on the projectile impact resistance represented by differential efficiency factor (DEF), structural integrity and area and height of impact crater has been evaluated. The superior projectile resistance of UHPFRC with corundum has been observed. Regarding the size of the aggregates, the incorporation of coarser aggregates brings better projectile impact resistance.

Low Velocity Impact Resistance of CPVC Pipes Exposed to Natural Outdoor Weathering Conditions

2012 ◽  
Vol 445 ◽  
pp. 959-964
Author(s):  
Z. Khan ◽  
Necar Merah ◽  
A. Bazoune ◽  
S. Furquan
Keyword(s):  
Impact Resistance ◽  
Outdoor Exposure ◽  
Impact Testing ◽  
Low Velocity Impact ◽  
Pipe Material ◽  
Low Velocity ◽  
Impact Energies ◽  
The Impact ◽  
Impact Events ◽  
Outdoor Weathering

Low velocity drop weight impact testing of CPVC pipes was conducted on 160 mm long pipe sections obtained from 4-inch (100 mm) diameter schedule 80 pipes. Impact test were carried out for the base (as received) pipes and after their exposure to out door natural weathering conditions in Dhahran, Saudi Arabia. The results of the impact testing on the natural (outdoor exposure) broadly suggest that the natural outdoor exposures produce no change in the impact resistance of CPVC pipe material for the impact events carrying low incident energies of 10 and 20J. At the impact energies of 35 and 50J the natural outdoor exposures appear to cause appreciable degradation in the impact resistance of the CPVC pipe material. This degradation is noted only for the longer exposure periods of 12 and 18 months.

scholarly journals Impact Resistance Analysis and Optimization of Variant Truss Beam Structure Based on Material Properties

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5847
Author(s):  
Xiaohao Li ◽  
Junqi Pan ◽  
Xingchen Zhou
Keyword(s):  
Simulation Analysis ◽  
Impact Load ◽  
Impact Resistance ◽  
Structure Design ◽  
Response Surfaces ◽  
Optimization Strategy ◽  
Buffer Effect ◽  
Characteristic Analysis ◽  
Beam Structure ◽  
The Impact

In order to meet the increasing application requirements with regards to structural impact resistance in industries such as mining, construction, aerospace engineering, and disaster relief and mitigation, this paper designs a variant truss beam structure with a large shrinkage ratio and high impact resistance. Based on the principle of the curved trajectory of scissor mechanisms, this paper conducts a finite element simulation analysis of the impact load on the truss beam structure, a theoretical analysis of the impact response and a relevant prototype bench-top experiment, completing a full study on the impact resistance mechanism of the designed variant truss beam structure under the impact load. In the paper, the buffer effect of the external load impact on the variant truss beam structure is analyzed from the perspective of the energy change of elastic–plastic deformation. This paper proposes an optimization strategy for the variant truss beam structure with the energy absorption rate as the optimization index through extensive analysis of the parameter response surfaces. The strategy integrates analyses on the response characteristic analysis of various configuration materials to obtain an optimal combination of component parameters that ensures that the strength of the truss beam structure meets set requirements. The strategy provides a feasible method with which to verify the effectiveness and impact resistance of a variant truss structure design.

scholarly journals Impact Response of Hammerhead Pier Fibrous Concrete Beams Designed with Topology Optimization

2020 ◽  
Author(s):  
Meivazhisalai Parasuraman Salaimanimagudam ◽  
Covaty Ravi Suribabu ◽  
Gunasekaran Murali ◽  
Sallal R. Abid
Keyword(s):  
Topology Optimization ◽  
Concrete Beams ◽  
Impact Load ◽  
Impact Resistance ◽  
Adaptive Mesh ◽  
Impact Response ◽  
Adaptive Meshing ◽  
Repeated Impact ◽  
Ductility Ratio ◽  
The Impact

Reducing the weight of concrete beams is a primary (beyond strength and durability) concern of engineers. Therefore, this research was directed to investigate the impact response of hammerhead pier concrete beams designed with density-based method topology optimization. The finite element topology optimization was conducted using Autodesk fusion 360 considering three different mesh sizes of 7 mm, 10 mm, and adaptive meshing. Three optimized hammerhead beam configurations; HB1, HB2, and HB3, respectively, with volume reductions greater than 50 %. In the experimental part of this research, nine beams were cast with identical size and configuration to the optimized beams. Three beams, identical to the optimized beams, were tested under static bending for verification purposes. In comparison, six more beams, as in the preceding three beams but without and with hooked end steel fibers, were tested under repeated impact load. The test results revealed that the highest flexural capacity and impact resistance at crack initiation and failure were recorded for the adaptive mesh beams (HB3 and HB3SF). The failure impact energy and ductility ratio of the beam HB3SF was higher than the beams HB1SF and HB2SF by more than 270 %. The results showed that the inclusion of steel fiber duplicated the optimized beam’s impact strength and ductility several times. The failure impact resistance of fibrous beams was higher than their corresponding plain beams by approximately 2300 to4460 %, while their impact ductility ratios were higher by 6.0 to 18.1 times.

Interplay of fabric structure and shear thickening fluid impregnation in moderating the impact response of high-performance woven fabrics

2020 ◽  
Vol 54 (28) ◽  
pp. 4387-4395
Author(s):  
Sanchi Arora ◽  
Abhijit Majumdar ◽  
Bhupendra Singh Butola
Keyword(s):  
Beneficial Effect ◽  
Energy Absorption ◽  
Impact Energy ◽  
High Performance ◽  
Research Work ◽  
Impact Resistance ◽  
Woven Fabrics ◽  
Woven Fabric ◽  
Fabric Structure ◽  
The Impact

The beneficial effect of STF impregnation in enhancing the impact resistance of high-performance fabrics has been extensively reported in the literature. However, this research work reports that fabric structure has a decisive role in moderating the effectiveness of STF impregnation in terms of impact energy absorption. Plain woven fabrics having sett varying from 25 × 25 inch−1 to 55 × 55 inch−1 were impregnated with STF at two different padding pressures to obtain different add-ons. The impact energy absorption by STF impregnated loosely woven fabrics was found to be higher than that of their neat counterparts for both levels of add-on, while opposite trend was observed in case of tightly woven fabrics. Further, comparison of tightly woven plain, 2/2 twill, 3/1 twill and 2 × 2 matt fabrics revealed beneficial effect of STF impregnation, except for the plain woven fabric, establishing that there exists a fabric structure-STF impregnation interplay that tunes the impact resistance of woven fabrics.

Quasi-Static Lap Shear and Dynamic Impact of High Performance VHB™ Acrylic Foam and Adhesive Transfer Tape Bonded Aluminum Joints Subjected to Environmental Degradation

2005 ◽  
Author(s):  
Manoj Anakapalli ◽  
P. Raju Mantena ◽  
Ahmed Al-Ostaz ◽  
S. Jimmy Hwang
Keyword(s):  
High Performance ◽  
Shear Failure ◽  
Electrochemical Impedance ◽  
Impact Load ◽  
Bond Quality ◽  
Dynamic Impact ◽  
Impulse Frequency ◽  
Lap Shear ◽  
Failure Loads ◽  
The Impact

A range of 3M™ VHB™ acrylic foam tapes and high performance adhesive transfer tapes were used to bond 1” × 1/8″ (25.4 mm × 3.175 mm) aluminum 2024 T-4 adherends in single-lap joint (SLJ) and three-point end-notched flexure (ENF) configurations. Three types of 0.045” thick double-coated acrylic foam tapes: Foam 41, 50 and 52 (firm, soft and softer), and three types of adhesive transfer tapes: Adhesives 69, 73 and 85 (0.005”, 0.01” and 0.005” thick, respectively) were used for this study. The samples were subjected to two types of aggressive environments simulating extreme service conditions: freeze-thaw cycling from 10°F to 50°F at 6 cycles per day (ASTM C666 Procedure A) for 21 days with samples immersed in water; heat-cool cycling (with 90% of maximum recommended temperature by the manufacturer of both acrylic foam and adhesive transfer tapes attained at 70% relative humidity) and 3 cycles per day for 21 days. Initially the impulse-frequency response vibration and electrochemical impedance spectroscopy (EIS) techniques were used for monitoring bond quality nondestructively and selecting the best out of 250 fabricated samples. After obtaining baseline data, the specimens were subjected to quasi-static lap-shear and dynamic impact loading to compare their lap-shear failure loads and shear energy along with the impact load and energy absorbed.

scholarly journals Axial Impact Load of a Concrete-Filled Steel Tubular Member with Axial Compression Considering the Creep Effect

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3134 ◽  
Author(s):  
Tao Lan ◽  
Guangchong Qin ◽  
Jinzhao Zhuang ◽  
Youdi Wang ◽  
Qian Zheng ◽  
...  
Keyword(s):  
Impact Load ◽  
Slenderness Ratio ◽  
Concrete Strength ◽  
Pressure Ratio ◽  
Impact Resistance ◽  
Axial Pressure ◽  
Axial Impact ◽  
Creep Effect ◽  
The Impact ◽  
Peak Value

The dynamic loads acting on concrete-filled steel tubular members under axial impacts by rigid bodies were studied herein by FEM. The whole impact process was simulated and the time history of the impact load was obtained. The effects of eight factors on the axial impact load were studied; these factors were the impact speed, mass ratio, axial pressure ratio, steel ratio, slenderness ratio, concrete strength, impact position, and boundary conditions. Besides this, the effects of concrete creep on the impact load were also considered by changing the material parameters of the concrete. The results show that axial impact load changes with time as a triangle. The peak value of impact load increases and the impact resistance improves with the growth of the axial pressure ratio, steel ratio, slenderness ratio, and concrete strength after creep occurs. As the eccentricity of the axial impact acting on a concrete-filled steel tubular member increases, the peak value of the impact load decreases. The enhancement of constraints at both ends of the member can improve the impact resistance. The creep reduction coefficients for the peak axial impact load of a concrete-filled steel tubular member under axial compression and considering the creep effect over 6 months and 30 years are 0.60 and 0.55, respectively. A calculation formula for the peak value of impact load was suggested based on the existing formula, and its accuracy was proved by finite element calculation in this study.

scholarly journals Experimental Investigation on Relations Between Impact Resistance and Tensile Properties of Cement-Based Materials Reinforced by Polyvinyl Alcohol Fibers

2019 ◽  
Vol 9 (20) ◽  
pp. 4434
Author(s):  
Ju Zhang ◽  
Pucun Bai ◽  
Changwang Yan ◽  
Shuguang Liu ◽  
Xiaoxiao Wang
Keyword(s):  
Polyvinyl Alcohol ◽  
Tensile Properties ◽  
Impact Load ◽  
Impact Resistance ◽  
Crater Diameter ◽  
Cement Based Materials ◽  
Weight Test ◽  
Ultimate Failure ◽  
Drop Weight Test ◽  
The Impact

Cement-based material is brittle and is easily damaged by an impact load with a few blows. The purpose of this paper is to study the relations between the impact resistance and tensile properties of cement-based materials reinforced by polyvinyl alcohol fiber (PVA-FRCM). A drop-weight test and uniaxial tension test were performed. The relations were studied based on the experimental results, including the relation between the blow number and the tensile stress at the first visible cracking (σc) and the relation between the blow number and the tensile strain at the ultimate failure (εf). Results showed that the blow number for the first visible crack for disc impact specimens increases obviously with the increase of σc of slab specimens. The crater diameter and blow number for ultimate failure of the disc specimens increase with the increase of εf of slab specimens. For the PVA-FRCM specimens with larger σc and εf, much more blows are needed to cause both the first visible crack and ultimate failure. Polyvinyl alcohol fibers can reinforce impact resistance and tensile properties of cement-based materials.

scholarly journals Experimental Tests and Reliability Analysis of the Cracking Impact Resistance of UHPFRC

Fibers ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 74
Author(s):  
Hussain A. Jabir ◽  
Sallal R. Abid ◽  
Gunasekaran Murali ◽  
Sajjad H. Ali ◽  
Sergey Klyuev ◽  
...  
Keyword(s):  
High Performance ◽  
Steel Fiber ◽  
Impact Resistance ◽  
High Strength ◽  
Experimental Tests ◽  
Fiber Reinforced Concrete ◽  
Fiber Types ◽  
Impact Performance ◽  
High Performance Fiber ◽  
The Impact

Ultra-high performance (UHP) concrete is a special type of fibrous cementitious composite that is characterized by high strength and superior ductility, toughness, and durability. This research aimed to investigate the resistance of ultra-high performance fiber-reinforced concrete (UHPFRC) against repeated impacts. An adjusted repeated drop mass impact test was adopted to evaluate the impact performance of 72 UHPFRC disc specimens. The specimens were divided into six mixtures each of 12 discs. The only difference between the mixtures was the types of fibers used, while all other mixture components were the same. Three types of fibers were used: 6 mm micro-steel, 15 mm micro-steel, and polypropylene. All mixtures included 2.5% volumetric content of fibers, however with different combinations of the three fiber types. The test results showed that the mixtures with the 15 mm micro-steel fiber absorbed a higher number of impact blows until cracking compared to other mixtures. The mixture with pure 2.5% of 15 mm micro-steel fiber exhibited the highest impact resistance, with percentage increases over the other mixtures ranging from 25 to 140%. In addition, the Weibull distribution was used to investigate the cracking impact resistance of UHP at different levels of reliability.

Influence of Crumb Rubber on Impact Energy of Steel Fiber Concrete Beams

2015 ◽  
Vol 802 ◽  
pp. 196-201
Author(s):  
Ahmed Tareq Noaman ◽  
Badorul Hisham Abu Bakar ◽  
Hazizan Md. Akil
Keyword(s):  
Impact Energy ◽  
Steel Fiber ◽  
Concrete Beams ◽  
Impact Load ◽  
Crumb Rubber ◽  
Fine Aggregate ◽  
Low Velocity ◽  
Fiber Concrete ◽  
Steel Fiber Concrete ◽  
The Impact

This paper presents the impact energy of steel fiber concrete beams at first crack and failure with different replacement ratios of crumb rubber. The test was carried out using simple low velocity drop weight test rig for both normal concrete (NC) and steel fiber concrete (SFC). The crumb rubber with particle size of 1 – 2 mm was added with replacement ratios of 5%, 15%, and 25% by volume of fine aggregate. Six batches consisting of 6 beams (100x100x500 mm) containing 0.5% of hooked end steel fibers were tested under impact load in accordance with ACI Committee 544. The specimens were tested at the age 90 days after curing in water. The results show a reduction in the compressive strength for both NC and SFC with the incorporation of crumb rubber with greater reduction at higher crumb rubber content. However, the measured impact energy for both NC and SFC was foundincreasing with the crumb rubber replacement.

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