【摘要】：為了初步地了解廢棄纖維再生混凝土梁的受剪和受彎性能,本文分別對(duì)12根和14根不同廢棄纖維摻入量及不同再生骨料取代率下的矩形截面梁進(jìn)行了斜截面受剪和受彎性能試驗(yàn)。廢棄纖維的摻入量的體積分別為0.08%、0.12%、0.16%,纖維長(zhǎng)度分別為12mm、 19mm、30mm、再生骨料取代率分別為0、50%、100%。梁截面尺寸分別為2300mm×200mm ×300mm和2250mm×150mm×300mm。本文對(duì)廢棄纖維再生混凝土梁在斜截面以及正截面短期荷載作用下的受力性能、破壞形態(tài)及變形特征有了初步了解,同時(shí)研究分析了廢棄纖維再生混凝土梁的斜截面和正截面承載能力、抗裂度、正常使用荷載下的最大裂縫寬度和撓度情況,并按照現(xiàn)行《混凝土結(jié)構(gòu)設(shè)計(jì)規(guī)范》GB50010-2010中相關(guān)公式對(duì)廢棄纖維再生混凝土梁的開裂彎矩、受彎極限承載力、跨中撓度、最大裂縫寬度以及斜截面受剪極限承載力的理論計(jì)算的適用性進(jìn)行了分析。通過對(duì)試驗(yàn)結(jié)果的分析研究,本文總結(jié)出以下主要結(jié)論：(1) 廢棄纖維再生混凝土梁的正截面混凝土應(yīng)變均符合平截面假定；受剪破壞的廢棄纖維再生混凝土梁在極限荷載的40%以內(nèi)符合平截面假定;(2) 廢棄纖維的摻入可以改善再生混凝土梁的抗裂性,使得廢棄纖維再生混凝土梁的抗裂性能達(dá)到甚至超過普通混凝土梁。并且可以更好地限制裂縫的發(fā)展,提高了試件的剛度。(3) 廢棄纖維的摻入使廢棄纖維再生混凝土梁的延性明顯提高。在試件受拉鋼筋開始屈服之后至達(dá)到極限承載力之前,廢棄纖維再生混凝土梁相比于普通混凝土梁以及再生混凝土梁仍能保持較長(zhǎng)時(shí)間的持載能力,試件變形增大的同時(shí),承載力仍能有一定的提升。(4) 廢棄纖維再生混凝土梁在各階段承載能力均達(dá)到甚至超過普通混凝土梁。按照現(xiàn)行《規(guī)范》公式對(duì)廢棄纖維再生混凝土梁的正截面受彎和斜截面受剪承載力進(jìn)行計(jì)算是可行的,且計(jì)算結(jié)果偏于安全。(5) 按照現(xiàn)行《規(guī)范》公式對(duì)廢棄纖維再生混凝土梁的撓度進(jìn)行驗(yàn)算是可行的,且計(jì)算結(jié)果偏于安全。(6) 按照現(xiàn)行《規(guī)范》公式對(duì)廢棄纖維再生混凝土梁的最大裂縫寬度進(jìn)行驗(yàn)算是可行的,但相比于普通混凝土梁,按照《規(guī)范》公式計(jì)算的最大裂縫寬度安全儲(chǔ)備較大。本文提出修正系數(shù)。系數(shù)v建議取1.40。(7) 通過對(duì)各廢棄纖維摻入量下廢棄纖維再生混凝土梁受彎以及斜截面受剪性能的綜合對(duì)比發(fā)現(xiàn),廢棄纖維再生混凝土梁受彎以及斜截面受剪性能并不與廢棄纖維的摻入量的多少以及纖維長(zhǎng)度的長(zhǎng)短成正比。
[Abstract]:In order to understand the shear and flexural behavior of recycled concrete beams, In this paper, the shear and bending properties of 12 and 14 rectangular beams with different waste fiber content and different replacement ratio of recycled aggregate were tested. The volume of waste fiber was 0.08 and 0.120.16, the fiber length was 12mm and 19mm / 30mm, respectively, and the replacement rate of recycled aggregate was 0.50mm and 100mm respectively. The cross section sizes of the beams are 2300mm 脳 200mm 脳 300mm and 2250mm 脳 150mm 脳 300mm. In this paper, the mechanical behavior, failure form and deformation characteristics of abandoned fiber regenerated concrete beams under the action of oblique section and normal section are preliminarily understood. At the same time, the load-bearing capacity, crack resistance, maximum crack width and deflection of abandoned fiber recycled concrete beams under normal load are studied and analyzed. According to the relevant formula in GB50010-2010, the cracking moment, ultimate flexural capacity and mid-span deflection of abandoned fiber reinforced recycled concrete beams are studied. The applicability of theoretical calculation of maximum crack width and shear ultimate bearing capacity of inclined section is analyzed. The main conclusions are summarized as follows: (1) the normal section concrete strain of abandoned fiber regenerated concrete beam conforms to the assumption of plane section; The shear failure of abandoned fiber reinforced recycled concrete beams is within 40% of the ultimate load according to the assumption of plane section. (2) the crack resistance of recycled concrete beams can be improved by adding waste fiber, and the crack resistance of recycled concrete beams is even higher than that of ordinary concrete beams. And it can better limit the crack development and improve the stiffness of the specimen. (3) the ductility of recycled concrete beams is obviously improved by the incorporation of waste fiber. After the tensile steel bar begins to yield to reach the ultimate bearing capacity, the recycled fiber reinforced concrete beam can maintain the capacity of holding load for a long time compared with the ordinary concrete beam and the recycled concrete beam, and the deformation of the specimen increases at the same time. The bearing capacity can still be improved to some extent. (4) the bearing capacity of abandoned fiber recycled concrete beams reaches or even exceeds that of ordinary concrete beams in every stage. According to the current formula, it is feasible to calculate the shear capacity of normal section and oblique section of abandoned fiber recycled concrete beam. And the calculation results are more safety. (5) it is feasible to check the deflection of abandoned fiber recycled concrete beams according to the current formula. And the calculation results are more safety. (6) it is feasible to check the maximum crack width of abandoned fiber recycled concrete beams according to the current formula, but compared with ordinary concrete beams, The safety reserve of maximum crack width calculated according to the formula is large. In this paper, the correction coefficient is proposed. Coefficient v suggested 1.40. (7) through the comprehensive comparison of the shear behavior of recycled concrete beams with waste fibers, the flexural behavior and the shear behavior of oblique sections of recycled concrete beams are found. The shear behavior of recycled concrete beams is not proportional to the amount of waste fibers and the length of the fibers.
【學(xué)位授予單位】：沈陽建筑大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TU377.9

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本文編號(hào)：2304991