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    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/1255


    Title: 混凝土裂縫密度之量測方法;Measurement method of crack density in concrete
    Authors: 張道武;Dao-wu Zhang
    Contributors: 土木工程研究所
    Keywords: 裂縫密度;裂縫間距;裂縫頻率;表面裂縫;Crack density;Crack spacing;Crack frequencies
    Date: 2009-05-01
    Issue Date: 2009-09-18 17:24:55 (UTC+8)
    Publisher: 國立中央大學圖書館
    Abstract: 常用混凝土裂縫定量參數包含了裂縫寬度、裂縫深度、裂縫間距與裂縫密度,裂縫間距定義是裂縫平面橫截線上的平均裂縫距離;裂縫密度的定義是單位面積內的裂縫總長度。以往裂縫密度中裂縫長度的測量總是曠時費力,但裂縫間距的測量相對容易,本研究目的即著重在探討裂縫間距與裂縫密度之關聯性,期望藉由易量測的裂縫間距推算得出難測量的裂縫密度,並建立裂縫間距的標準量測方法。 量測方法是在裂縫表面覆蓋測線網格,可得測線與裂縫相交的交點數量稱為交點數;網格單元格內含有裂縫通過的數量占總數之百分比稱為格數比。既有文獻的概念中交點數和測線長成正比,其斜率可定義為裂縫間距,整理過去計算交點數來定裂縫間距的方法稱為交點法;另外經由理論推導與試驗驗證當改變測線網格的測線長度與排列間距時,測線間距會與格數比呈現正相關性,便以此為依據建立以計數格數比來計算裂縫間距的新方法稱為計格法。 探究裂縫間距與裂縫密度之關聯方面,從網狀裂縫基塊的多邊形相似性為出發點,在假設裂縫寬度可忽略、裂縫整體分布均勻等向、測線長遠大於排列間距、裂縫基塊為正多邊形與不考慮碎形理論與尺度效應的前提下,利用平面幾何關係的概念,推導得裂縫間距與裂縫密度之乘積為π/2,稱為裂縫常數,再加入曲折係數的觀念,對裂縫密度作曲折還原。 本研究主要為建立裂縫間距的量測流程計點法、計格法,再加入裂縫常數與曲折係數進行計算便可得裂縫密度。論述最後的部分,是以實際案例進行驗證,並且大量抽樣,統計測線長度與測線間距對裂縫間距與裂縫密度測量結果的變異性與誤差影響,歸納出適當的測線長度與測線間距建議值,加入計點法與計格法的量測流程中修定。 The factors of measuring cracks in concrete include crack widths, crack depth, crack spacing, crack density etc., yet this thesis will focus on developing an uncomplicated and understandable method to gauge the cracks block on crack spacing and crack density. According to the similarity of polygons of irregular map cracks, the purpose of the method is exploring the relations between the quantity of intersection point and percentage of the crack-crossed cells of the lattice-arranged lines and crack spacing and crack density by counting the numbers of complete cells instead of the current measurement - counting the numbers of intersection point. Under the hypotheses that crack widths could be passed over, cracks spread averagely, the lines are infinite and crack-based is square, inferring the product of crack spacing and crack density is π/2 by the geometry theory, fractal theory and scale effect are not considered in the study.
    Appears in Collections:[土木工程研究所] 博碩士論文

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