Drop-Weight Impact Resistance of Ultrahigh-Performance Concrete and the Corresponding Statistical Analysis

Author(s):  
Yalin Liu ◽  
Ya Wei
Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4000 ◽  
Author(s):  
Bing Liu ◽  
Jingkai Zhou ◽  
Xiaoyan Wen ◽  
Jianhua Guo ◽  
Xuanyu Zhang ◽  
...  

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.


Seikei-Kakou ◽  
1998 ◽  
Vol 10 (6) ◽  
pp. 381-388
Author(s):  
Hiroshi Kataoka ◽  
Tamotsu Tonegawa

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7773
Author(s):  
Jae-Hoon Lee ◽  
Jin-Seok Choi ◽  
Tian-Feng Yuan ◽  
Young-Soo Yoon

Following the fourth Industrial Revolution, electronic and data-based technology is becoming increasingly developed. However, current research on enhancing electromagnetic interference (EMI) shielding and the physical protection performance of structures incorporating these technologies is insufficient. Therefore, in this study aiming for the improvement of EMI shielding and structural performance of structures, twelve concrete walls were fabricated and tested to determine their shielding effectiveness and drop-weight impact resistance. Concrete walls strengthened by three thickness types of high-strength, high-ductility concrete (HSDC) have been considered. The test results showed that the shielding effectiveness with strengthening thickness increased by approximately 35.6–46.2%. Specimens strengthened by more than 40% and 10% of the strengthening area ratio of single- and double-layer, respectively, exhibited more than 20 dB of shielding effectiveness. Moreover, the relationship between the damaged area ratio and shielding effectiveness was evaluated by means of the drop-weight impact test. The structural performance and EMI shielding effectiveness improved as the HSDC thickness increased.


Author(s):  
Anish Ravindra Amin ◽  
Yi-Tang Kao ◽  
Bruce L. Tai ◽  
Jyhwen Wang

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.


2020 ◽  
Vol 897 ◽  
pp. 49-55 ◽  
Author(s):  
Hussain A. Jabir ◽  
Sallal R. Abid ◽  
Munther L. Abdul Hussein ◽  
Sajjad H. Ali

The impact resistance of micro-steel fiber-reinforced and hybrid fiber-reinforced reactive powder concrete is investigated in this study. Six groups of specimens were prepared with 2.5% volumetric contents of different combinations of fibers. For this purpose, micro-steel fibers with 6 and 15 mm length in addition to polypropylene fibers were used. Each group includes 12 identical specimens. The impact tests were conducted using the repeated drop-weight impact test of ACI 544-2R. However, higher drop-height (700 mm) and drop-weight (10 kg) were adopted to accelerate the failure and reduce the effort required to crack the specimens. The test results showed that the use of only 15 mm micro-steel fiber led to much higher impact resistance than other micro-steel fiber combinations. The recorded number of blows for the group with SF15 was 247, while those of SF6 and combined SF6 and SF15 were 127 and 112, respectively. The replacement of 0.5% of micro-steel fiber by 0.5% of PP fiber was found to reduce the impact resistance regardless of the type or combination of the used micro-steel fiber.


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