작성일 : 10-09-22 23:45
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크랙1.8mm간격은 자연치유된다.
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크랙이 적은 것은 7주 내지 5년에 걸쳐 자동으로 하자가 치유된다는 내용
Autogenous Healing
This phenomenon occurs between opposing surfaces of narrow cracks. The mechanism of the healing is the hard white ‘crust like’ formation on the concrete pipe known as calcium carbonate. The crack healing requires the presence of moisture, which when reacting with cement powder, restarts the hydration (curing) process. Autogenous healing has also been witnessed where debris enters the crack and over time fills the crack.
The strength of the healed crack has been studied under laboratory conditions. It has been suggested that full healing creates a monolithic structure, so the pipe is “as good as new”, and should be considered structurally sound and capable of performing in the manner originally intended.
Regardless of the mechanism, autogenous healing will occur in concrete pipe that has cracked. The question is how wide a crack can be healed? The answer is not simple.
Literature reports cracks as wide as 1.5mm (Loving) healed in a period of 5 years. Edvardsen found that cracks of 0.2mm healed completely within 7 weeks. It appears that the narrower the crack, the more rapid the healing can occur. The Ohio DOT has developed Supplemental Specification 802, Post Construction Inspection of Storm Sewers and Drainage Structures identifies the rehabilitation methods for installed pipe which has evidence of cracking. The specification requires the contractor to “Do Nothing” for cracks up to 1.8mm in width, with the expectation that autogenous healing will create a watertight pipe over a period of a few years.
OCPA Concrete Pipe Information Booklet
The Significance of Cracking in Concrete Pipe
Autogeneous Healing
[이 게시물은 선진산업님에 의해 2013-11-08 14:21:22 견적상담에서 이동 됨]
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