Rate-dependent compressive behavior of concrete confined with Large-Rupture-Strain (LRS) FRP
Rate-dependent compressive behavior of concrete confined with Large-Rupture-Strain (LRS) FRP
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DOI：
10.1016/j.compstruct.2021.114199
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发表时间：
2021-05
影响因子：
6.3
通讯作者：
Zhi Yan;Yu Bai;T. Ozbakkaloglu;W. Gao;J. Zeng
中科院分区：
文献类型：
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作者：
Zhi Yan;Yu Bai;T. Ozbakkaloglu;W. Gao;J. Zeng
聚萘(PEN)和聚对苯二甲酸乙二酯(PET)纤维的拉伸断裂应变大于5%，因此被称为大断裂应变(LRS)纤维增强聚合物(FRP)材料。其较大的断裂应变特性可能有助于显著提高钢筋混凝土结构的抗冲击性能。通过分离式霍普金森压杆(SHPB)试验，研究了LRS FRP约束混凝土的应变率效应。结果表明，与CFRP复合材料约束的混凝土试件相比，LRS FRP约束混凝土试件在单次冲击下表现出更好的抗冲击性能。LRS FRP约束混凝土试件的临界应变、抗压强度和韧性随着应变率的增加而增大。由于LRS FRP约束混凝土试件具有较大的断裂应变特性，在单次冲击后几乎没有明显的损伤。为了研究混凝土的损伤演化机理，将试件以相同的能量多次冲击，直至试件破坏。由于混凝土的渐进性破坏，在多次冲击下，混凝土的动态抗压强度和韧性都出现了下降。这些发现可能会促进LRS FRP材料作为一种很有前途的外护套材料在钢筋混凝土结构抗冲击设计领域的应用。
The polyethylene naphthalene (PEN) and polyethylene terephthalate (PET) fibers have a tensile rupture strain of over 5%, and hence they are referred to as large-rupture-strain (LRS) fiber reinforced polymer (FRP) materials. Their large rupture strain characteristics may contribute to significant improvement of the impact resistance of reinforced concrete (RC) structures. This study investigates the strain rate effect on LRS FRP-confined concrete through Split Hopkinson Pressure Bar (SHPB) test. Results revealed that LRS FRP-confined concrete specimens exhibited superior impact resistance behaviors compared to the counterpart confined with CFRP composites when subjected to a single impact. The critical strain, compressive strength and toughness of the LRS FRP-confined concrete specimen increased with increasing strain rate. Due to the large rupture strain characteristics, the LRS FRP-confined concrete specimen virtually had no visible damage after a single impact. To study the damage evolution mechanism of concrete, the specimens were impacted for multiple times with the same energy until the failure of the specimen. Due to progressive concrete damage, the dynamic compressive strength and toughness experienced a decrease during multiple impacts. These findings might promote the application of LRS FRP materials in the field of impact resistance design of RC structures as a promising external jacketing material.