凍融循環(huán)后預(yù)應(yīng)力混凝土梁受彎性能研究*
李琮琦1, 2，葛文杰2，曹大富2
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（1 江蘇大學(xué)土木工程與力學(xué)學(xué)院， 鎮(zhèn)江 212013; 2 揚(yáng)州大學(xué)建筑科學(xué)與工程學(xué)院， 揚(yáng)州 225127）
［摘要］為研究凍融循環(huán)次數(shù)對預(yù)應(yīng)力混凝土梁受彎性能的影響，制作了普通混凝土梁和預(yù)應(yīng)力度分別為0.35，0.52和0.62的預(yù)應(yīng)力混凝土梁各4根，將構(gòu)件經(jīng)歷一定次數(shù)的凍融循環(huán)后進(jìn)行靜力受彎性能試驗。研究表明，預(yù)應(yīng)力度和凍融循環(huán)次數(shù)對預(yù)應(yīng)力混凝土梁的承載力影響比較明顯，隨凍融循環(huán)次數(shù)的增加，預(yù)應(yīng)力混凝土梁的受彎承載力明顯下降。中、低預(yù)應(yīng)力度混凝土梁的受彎承載力隨凍融循環(huán)次數(shù)增加而下降的速率較高預(yù)應(yīng)力度混凝土梁的緩慢。凍融循環(huán)后預(yù)應(yīng)力混凝土梁的開裂彎矩可按規(guī)范相關(guān)公式計算，極限彎矩也可按規(guī)范公式計算，但需考慮綜合影響系數(shù)。［關(guān)鍵詞］預(yù)應(yīng)力混凝土梁; 預(yù)應(yīng)力度; 凍融循環(huán); 受彎性能中圖分類號：TU375.1 文獻(xiàn)標(biāo)識碼：A 文章編號：1002-848X(2015)24-0101-05
Study on the mechanical behaviors of prestressed concrete beams after freeze-thaw cyclesLi Congqi1, 2, Ge Wenjie2, Cao Dafu2(1 College of Civil Engineering and Mechanics, Jiangsu University, Zhenjiang 212013, China; 2 College of Civil Science and Engineering, Yangzhou University, Yangzhou 225127, China)Abstract: In order to study the flexural behavior of prestressing concrete beams after freeze-thaw cycles, four normal concrete beams and four prestressed concrete beams with three different partial prestressing ratios (PPR) 0.35, 0.52 and 0.62 were made and theirs static flexural experiments were carried out after certain freeze-thaw cycles. The results show that PPR and freeze-thaw cycles are the two main influence factor to the flexural behavior of prestressing concrete beams. Ultimate moment decreases significantly with the increasing of freeze-thaw cycles. Ultimate moments of prestressing concrete beams with moderate and low PPR decrease slower than prestressing concrete beams with high PPR. Cracking moment of prestressed concrete beams after the freeze-thaw cycle could calculate by current design code of concrete structure. Ultimate moment could also calculate by current design code, but comprehensive influence coefficient should be taken into consideration.Keywords: prestressed concrete beam; partial prestressing ratio (PPR); freeze-thaw cycle; flexural behavior
*國家自然科學(xué)基金資助項目(51278445, 51278230, 50978224)， 江蘇省普通高校研究生科研創(chuàng)新計劃 (CXZZ12-0655)。作者簡介：李琮琦，碩士，講師， Email: licq@yzu.edu.cn。
