CAJ | 학술논문

利用我国西南部某特高拱坝施工现场的拌合楼，浇筑成型骨料最大粒径150 mm的大坝混凝土楔入劈拉试件，试件尺寸分别为800 mm ×800 mm ×450 mm、1000 mm ×1000 mm ×450 mm和1200 mm ×1200 mm ×450 mm。通过试验获得现场浇筑大坝混凝土试件的起裂荷载，进而由有限元计算得到其起裂断裂韧度值，分析了龄期变化对起裂断裂韧度的影响规律，给出了起裂断裂韧度随试件尺寸的变化规律。结果表明，通过现场浇筑试件，得到大坝混凝土的起裂断裂韧度，能够真实反映大坝的实际断裂性能。现场浇筑大坝混凝土的起裂断裂韧度随着龄期增加而增加，180 d龄期的现场浇筑大坝混凝土的起裂断裂韧度在试件有效高度800~1200 mm范围内不存在明显的尺寸效应。
이용아국서남부모특고공패시공현장적반합루，요축성형골료최대립경150 mm적대패혼응토설입벽랍시건，시건척촌분별위800 mm ×800 mm ×450 mm、1000 mm ×1000 mm ×450 mm화1200 mm ×1200 mm ×450 mm。통과시험획득현장요축대패혼응토시건적기렬하재，진이유유한원계산득도기기렬단렬인도치，분석료령기변화대기렬단렬인도적영향규률，급출료기렬단렬인도수시건척촌적변화규률。결과표명，통과현장요축시건，득도대패혼응토적기렬단렬인도，능구진실반영대패적실제단렬성능。현장요축대패혼응토적기렬단렬인도수착령기증가이증가，180 d령기적현장요축대패혼응토적기렬단렬인도재시건유효고도800~1200 mm범위내불존재명현적척촌효응。
In this paper,the study aims to examine the initial fracture toughness KIinic of dam concrete ob?tained directly from a construction site. All test specimens with a maximum aggregate size of dmax = 150 mm were cast on site of an actual super-high arch dam in southwest China, and the dimensions of the wedge-splitting specimen were 800 mm × 800 mm × 450 mm,1000 mm × 1000 mm × 450 mm,1200 mm × 1200 mm × 450 mm, respectively. Based on the experimentally acquired initial cracking loads, the initial fracture toughness KI inic of the site-casting specimens was numerically obtained using the finite element method. Fur?thermore,the effect of specimen age and size on initial fracture toughness was analyzed and discussed. The results show that real fracture parameter KI inic of a super-high arch dam could be obtained by casting the test specimens at the construction site. The initial fracture toughness KI inic of the site-casting specimens in?creases with specimen age. The KI inic of the site-casting specimens at the age of 180 days is independent of specimen size at depths of 800 mm to 1200 mm.