| 袁群,赵国藩.老化钢筋混凝土结构的分形性质分析[J].水利学报,2000,31(12):0021-0026 |
| 老化钢筋混凝土结构的分形性质分析 |
| Fractal characteristics of aged reinforced concrete structure |
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| DOI： |
| 中文关键词: 钢筋混凝土 老化 分形 均匀性 裂缝 碳化 混凝土强度 |
| 英文关键词: reinforced concrete aging fractal evenness crack carbonization concrete strength |
| 基金项目: |
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| 摘要点击次数: 1651 |
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| 中文摘要: |
| 混凝土结构中的超声声速测值或回弹测值被描绘成一立体图形时，图形上表面的起伏程度反映了结构混凝土的均匀程度。计算分析发现，超声声速值和回弹值的功率谱与圆频率有负幂率关系，表明立体图的上表面即混凝土均匀性具有分形性质。由于代表混凝土不均匀程度的超声声速和回弹分维数，与构件混凝土强度和混凝土碳化深度有着良好的相关关系，混凝土的均匀性就与结构的老化进程相关，是进行结构耐久性分析时需要考虑的一个因素。另外，实例计算表明，混凝土裂缝的分布也具有分形的统计自相似性，其分布的分维数能较好地表征裂缝的发育程度，且与结构老化的其它指标相互印证。因此，裂缝分布的分维数也可以作为衡量结构老化程度的一个有效指标。 |
| 英文摘要: |
| The 3-D distribution variations of measured ultrasonic velocity and rebound in concrete tructure reflct the evenness of concrete performance. The power spectrums of the ultrasonic and the rebound are in negative exponent related to circular frequency. It means the upper surface of the 3-D distribution diagram i. e. the evenness of concrete possesses fractal property. The fractal dimensions of ultrasonic velocity and rebound, which represent the concrete evenness, are strongly related to concrtet strength and its carbonization depth. Thus, the concrete evenness is related to the aging process of the structure. Furthermore, the calculation result shows that the distribution of concrete cracks has the characteristic of self-similarity of fractal statistics, and the fractal dimension of the distribution can well characterize the growth of cracks. Thereby, the fractal dimension of crack distribution is an effective index for appraisal of structure aging. |
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