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摘要:
The meso-structure of concrete, which determines its apparent performance, is closely related to the maximum aggregate size (MAS) and aggregate volume. At cryogenic temperatures, due to the freezing of pore water, the internal structure of concrete is changed, leading to some difference in the role of coarse aggregate particles. In this study, the meso-mechanical modeling method was adopted based on the continuous grading aggregate model to investigate the influence of content and size of aggregate at cryogenic temperatures. The uniaxial compressive and uniaxial tensile behavior of concrete cubic specimens (sized by 150 x 150 x 150 mm(3)) with various aggregate volumes (15 % 45 %) and MAS values (12 mm similar to 36 mm) were simulated with consideration of cryogenic temperatures effects. The variation of compressive strength, tensile strength, elastic modulus, and fracture to energy with maximum aggregate size and aggregate volume fractions at cryogenic temperatures was investigated, and the related influencing mechanism was analyzed. The numerical results demonstrated that the failure patterns of specimens at cryogenic temperature show some differences compared with those at ambient temperature. Besides, it was indicated that the effect of maximum aggregate size and aggregate volume on the elastic modulus and the energy to fracture is consistent with those at ambient temperature. At cryogenic temperatures, the compressive strength is improved with the increase of maximum aggregate size. For the smaller aggregate volume fraction (15 % similar to 30 %), the tensile strength at cryogenic temperatures tends to increase as the increase of maximum aggregate size, while an opposite trend appeared at larger aggregate volume. Additionally, as the increase of aggregate volume fractions, the compressive strength decreases first and then increases at cryogenic temperatures, while the tensile strength and elastic modulus exhibit a trend of increase. It is concluded that cryogenic temperatures can enhance the influence of maximum aggregate size on tensile strength, but weaken the influence of aggregate volume fractions on strengths.
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来源 :
ENGINEERING FRACTURE MECHANICS
ISSN: 0013-7944
年份: 2022
卷: 273
5 . 4
JCR@2022
5 . 4 0 0
JCR@2022
ESI学科: ENGINEERING;
ESI高被引阀值:49
JCR分区:1
中科院分区:2
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