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| Fourier vibration of massive concrete by demolding |
| Revised:August 31, 2002 |
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| DOI：10.7511/jslx20042029 |
| KeyWord:concrete,demolding,surface protection,Fourier vibration |
| Huang Dahai |
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| Abstract: |
| Because of increasing demands on concrete durability, more and more attentions are paid on damage mechanics on the surface of early-age concrete, in which temperature change is one of the most dangerous environmental factor that should be discussed. In this paper, a simplified numerical model of massive concrete is applied to simulate the temperature process by move out the molds (demolding) from solidified concrete and covering it with heat insulated material. According to Fourier heat conduction law, when the formwork of concrete is demolded, heat, generated by cement, would flow from inner part of concrete to outside, and almost every point would has the same flow speed. And when the outside boundary is covered with heat insulated material, the heat flow would be hold back suddenly, and the Fourier vibration would be found in the internal part. As a matter of fact, temperature vibration in concrete is impossible, especially for the part far away from the boundary. So, some thing is misunderstood. Through analytical method, the reason is discovered and the relationship between disturbed time and Fourier vibration impact is presented, which indicates that Fourier vibration can be used to explain the false response phenomenon. At last, an approach to eliminate Fourier vibration is suggested. |
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