华南理工大学学报（自然科学版）
華南理工大學學報（自然科學版）
화남리공대학학보（자연과학판）
Journal of South China University of Technology(Natural Science Edition)
2015年
8期
113-118
,共6页
锈蚀钢筋混凝土梁%抗弯刚度%锈蚀疲劳%疲劳加载%挠度
鏽蝕鋼觔混凝土樑%抗彎剛度%鏽蝕疲勞%疲勞加載%撓度
수식강근혼응토량%항만강도%수식피로%피로가재%뇨도
corroded reinforced concrete beams%flexural stiffness%corrosion fatigue%fatigue loading%deflection
通过13根钢筋混凝土试验梁的加速锈蚀试验与疲劳加载试验,研究了锈蚀钢筋混凝土梁在疲劳反复荷载作用下的破坏形态及刚度变化.试验结果表明:所有锈蚀后的试验梁在循环加载到一定次数后,均发生以某一根主筋疲劳断裂为标志的疲劳破坏;未锈蚀的试验梁在循环加载200万次后不发生疲劳破坏,并且疲劳作用对未锈蚀梁的静力破坏形态及极限承载能力没有实质影响.分析了疲劳作用下锈蚀钢筋混凝土梁刚度的变化规律,发现其存在明显的两阶段特征,即缓慢减小并趋于稳定.根据试验实测数据,引入分别考虑钢筋锈蚀与疲劳作用的刚度修正系数,定量化地提出了疲劳加载下锈蚀钢筋混凝土梁刚度的修正计算公式,并对公式计算值与试验实测值进行了对比验证.该公式可用于锈蚀钢筋混凝土梁桥在长期活载作用下挠度变形的计算与评估.
通過13根鋼觔混凝土試驗樑的加速鏽蝕試驗與疲勞加載試驗,研究瞭鏽蝕鋼觔混凝土樑在疲勞反複荷載作用下的破壞形態及剛度變化.試驗結果錶明:所有鏽蝕後的試驗樑在循環加載到一定次數後,均髮生以某一根主觔疲勞斷裂為標誌的疲勞破壞;未鏽蝕的試驗樑在循環加載200萬次後不髮生疲勞破壞,併且疲勞作用對未鏽蝕樑的靜力破壞形態及極限承載能力沒有實質影響.分析瞭疲勞作用下鏽蝕鋼觔混凝土樑剛度的變化規律,髮現其存在明顯的兩階段特徵,即緩慢減小併趨于穩定.根據試驗實測數據,引入分彆攷慮鋼觔鏽蝕與疲勞作用的剛度脩正繫數,定量化地提齣瞭疲勞加載下鏽蝕鋼觔混凝土樑剛度的脩正計算公式,併對公式計算值與試驗實測值進行瞭對比驗證.該公式可用于鏽蝕鋼觔混凝土樑橋在長期活載作用下撓度變形的計算與評估.
통과13근강근혼응토시험량적가속수식시험여피로가재시험,연구료수식강근혼응토량재피로반복하재작용하적파배형태급강도변화.시험결과표명:소유수식후적시험량재순배가재도일정차수후,균발생이모일근주근피로단렬위표지적피로파배;미수식적시험량재순배가재200만차후불발생피로파배,병차피노작용대미수식량적정력파배형태급겁한승재능력몰유실질영향.분석료피노작용하수식강근혼응토량강도적변화규률,발현기존재명현적량계단특정,즉완만감소병추우은정.근거시험실측수거,인입분별고필강근수식여피노작용적강도수정계수,정양화지제출료피로가재하수식강근혼응토량강도적수정계산공식,병대공식계산치여시험실측치진행료대비험증.해공식가용우수식강근혼응토량교재장기활재작용하뇨도변형적계산여평고.
Based on the accelerated corrosion test and the fatigue loading test of thirteen reinforced concrete beam specimens, the failure mode and flexural stiffness of corroded reinforced concrete ( RC) beams under fatigue loads are investigated.The test results show that, after cyclic loading a certain number of times, fatigue failure occurs in all the corroded beam specimens and it is marked by the fatigue fracture of a main reinforcing bar, and that, nofa-tigue failure occurs in uncorroded specimens after cyclic loading two million times, and the fatigue effect has no substantial influence on the static failure mode and the ultimate bearing capacity of uncorroded RC beams.More-over, analysis on the flexural stiffness change of corroded RC beams under the effect of the fatigue loading indicates that there are two obvious stages, specifically, the flexural stiffness decreases slowly and then tends to be stable. According to the measured data, the stiffness correction coefficients, which take into account the steel bar corrosion and the fatigue effect respectively, are introduced to quantitatively derive the correction formula calculating the flexural stiffness of the corroded RC beams under the fatigue loading, and the formula is then verified by comparing the calculated values with the measured ones.It is also found that the proposed formula can be used to calculate and evaluate the deflection of corroded RC girder bridges under long-term live loads.
