TRC加固RC梁的彎曲疲勞破壞過程和應(yīng)變發(fā)展的試驗研究
發(fā)布時間:2018-06-03 19:48
本文選題:纖維編織網(wǎng)增強混凝土 + 受彎梁; 參考:《工程力學(xué)》2015年S1期
【摘要】:該文采用四點彎曲加載方式研究了加固方式、配網(wǎng)率、配筋率、損傷程度等對TRC加固RC梁疲勞壽命、破壞過程及應(yīng)變發(fā)展的影響。試驗結(jié)果發(fā)現(xiàn):TRC加固梁在疲勞荷載作用下其破壞過程可以分為三個階段。第一階段:循環(huán)次數(shù)大約在4萬次以內(nèi),新的裂縫會不斷產(chǎn)生,此階段末裂縫基本出齊,該階段相對加固梁的整個壽命過程較短;第二階段表現(xiàn)為加固梁的撓度幾乎不變,該階段末梁會產(chǎn)生新的裂縫,并形成主裂縫;第三階段:加固梁的跨中撓度迅速增加,在時間很短的情況下梁發(fā)生疲勞破壞。加固梁的混凝土壓應(yīng)變與受拉鋼筋應(yīng)變隨荷載循環(huán)次數(shù)的增加也呈三個階段發(fā)展:初始發(fā)展、穩(wěn)定發(fā)展和迅速發(fā)展。配網(wǎng)率和配筋率的增大都會減緩中和軸的上移速度,減小疲勞破壞時梁頂混凝土壓應(yīng)變,從而提高疲勞壽命。較大荷載作用下的靜力損傷會使加固梁的鋼筋應(yīng)變提前進入第三階段的發(fā)展,會減小RC梁的疲勞壽命。
[Abstract]:In this paper, the effects of strengthening mode, distribution ratio, reinforcement ratio and damage degree on fatigue life, failure process and strain development of RC beams strengthened with TRC are studied by using four-point bending loading method. The test results show that the failure process of the beam strengthened by TRC under fatigue load can be divided into three stages. The first stage: the number of cycles is about 40,000, the new cracks will continue to produce, at the end of this stage, the cracks are basically uniform, the whole life process of the strengthened beam is relatively short in this stage, and the second stage shows that the deflection of the strengthened beam is almost unchanged. At the end of this stage, new cracks will be produced and main cracks will be formed. In the third stage, the deflection in the middle span of strengthened beams increases rapidly, and fatigue failure occurs in the case of very short time. The compressive strain of concrete and the strain of tensile steel bar are also developed in three stages: initial development, steady development and rapid development. The increase of distribution ratio and reinforcement ratio will slow down the upward movement of the neutral axis and decrease the compressive strain of concrete at the top of the beam during fatigue failure, thus increasing the fatigue life. Static damage under large loads will advance the strain of reinforced beams into the third stage and reduce the fatigue life of RC beams.
【作者單位】: 中國礦業(yè)大學(xué)深部巖土力學(xué)與地下工程國家重點實驗室;中國礦業(yè)大學(xué)江蘇省土木工程環(huán)境災(zāi)變與結(jié)構(gòu)可靠性重點實驗室力學(xué)與建筑工程學(xué)院;
【基金】:國家自然科學(xué)基金項目(51478458,51108451) 江蘇省自然科學(xué)基金項目(BK2011220) 中央高;究蒲袠I(yè)務(wù)費專項資金項目(2014QNA79) 中國博士后和江蘇省博士后基金項目(2014T70559,2012M511337,1102082C)
【分類號】:TU375.1
【參考文獻】
相關(guān)期刊論文 前7條
1 尹世平;徐世p,
本文編號:1973966
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