| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of composing and manufacturing a matrix to avoid cracking of a precast segment as a tunnel lining, while enhancing its fireproof function. SOLUTION: Plastic fiber-mixed concrete 4 and/or 5 and normal concrete 6 are stacked as the matrix of a segment 2 to avoid a neutralization degradation resulting from microcracks caused by drying shrinkage force during fabrication and by changes in temperature and external load (earth pressure/water pressure) after use. While temperature is elevated in the event of a tunnel fire, the plastic melts at low temperatures at the early stage of the fire, creating penetrating voids, and avoiding the explosion of trapped water as steam and blasting due to the expansion of reinforcements. A method of forming different kinds of ready-mixed concrete such as plastic fiber-mixed concrete into a uniform thickness employs easy and economical manufacturing techniques based on such methods as centrifugal forming, using stationary forms, embedding curved plates, or setting plastic cages. COPYRIGHT: (C)2004,JPO
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