采用ECC改善钢筋混凝土深梁抗剪性能的试验研究
|
摘要
采用国产纤维制成的高性能水泥基复合材料(ECC)替代混凝土形成钢筋增强ECC深梁,并与3根普通钢筋混凝土深梁进行了集中荷载下抗剪性能对比试验研究。研究表明,RC深梁主要是剪切破坏和局压破坏,采用ECC后,RE1、RE3深梁的破坏模式从脆性破坏转为延性弯压破坏,RE深梁出现多条细密裂缝,且无碎屑剥落,整体性良好。相同配筋情况下,RE深梁的名义抗剪强度平均是RC深梁的1.25倍,延性系数平均是RC深梁的2.81倍。就名义极限剪切强度和裂缝宽度而言,ECC的使用至少可以替代RC深梁中0.3%的分布筋。
For the sake of improving the shear performance of reinforced concrete beams, an engineered cementitious composite(ECC) is introduced to substitute concrete in deep beams. A comparative experimental study on shear behaviors of three reinforced concrete(RC) deep beams and three reinforced ECC(RE) deep beams are carried out. The results show that RE deep beams present a ductile failure with the appearance of many fine diagonal cracks. The failure model of RC deep beams are mainly shear failure and local failure. The usage of ECC can turn brittle failure mode into ductility bending-compression failure mode. With the same reinforcement ratio, the nominal ultimate shear strength and the shear ductility index of RE deep beams are about 1.25 times and 2.81 times those of RC deep beams, respectively. Comparing to RC deep beams, ECC can substitute for the 0.3% distributing bars in the aspect of nominal ultimate shear strength and the width of cracks.
For the sake of improving the shear performance of reinforced concrete beams, an engineered cementitious composite(ECC) is introduced to substitute concrete in deep beams. A comparative experimental study on shear behaviors of three reinforced concrete(RC) deep beams and three reinforced ECC(RE) deep beams are carried out. The results show that RE deep beams present a ductile failure with the appearance of many fine diagonal cracks. The failure model of RC deep beams are mainly shear failure and local failure. The usage of ECC can turn brittle failure mode into ductility bending-compression failure mode. With the same reinforcement ratio, the nominal ultimate shear strength and the shear ductility index of RE deep beams are about 1.25 times and 2.81 times those of RC deep beams, respectively. Comparing to RC deep beams, ECC can substitute for the 0.3% distributing bars in the aspect of nominal ultimate shear strength and the width of cracks.
引文
[1]徐世烺,李贺东.超高韧性水泥基复合材料研究进展及其工程应用[J].土木工程学报,2008,41(6):13-17.
[2]杨忠,刘成建,张文健,等.钢筋增强高韧性水泥基复合材料梁受剪延性分析[J].人民长江,2014(13):79-81.
[3]侯利军,陈达,徐世娘,等.无腹筋RUHTCC梁抗剪性能试验研究[J].东南大学学报:自然科学版,2014,44(1):133-139.
[4]PAEGLE I,FISCHER G.Phenomenological interpretation of the shear behavior of reinforced Engineered Cementitious Composite beams[J].Cement and Concrete Composites,2016,73:213-225.
[5]ZIJL G P A G V.Improved mechanical performance:Shear behaviour of strain-hardening cement-based composites(SHCC)[J].Cement and Concrete Research,2007,37(8):1241-1247.
[6]SHIMIZU K,KANAKUBO T,KANADA T,et al.Shear Behavior of PVA-ECC Beams[J].Materials and Structures,2006,35(30):443-351.
[7]许青青.超高韧性水泥基复合材料在深受弯构件中的应用研究[D].大连:大连理工大学,2016.
[8]陈止戈,刘岳,钱国梁,等.钢筋混凝土简支深梁的试验研究[J].建筑结构,1984(1):40-45.
[9]SAHOO D R,MARAN K,KUMAR A.Effect of steel and synthetic fibers on shear strength of RC beams without shear stirrups[J].Construction and Building Materials,2015,83:150-158.
[2]杨忠,刘成建,张文健,等.钢筋增强高韧性水泥基复合材料梁受剪延性分析[J].人民长江,2014(13):79-81.
[3]侯利军,陈达,徐世娘,等.无腹筋RUHTCC梁抗剪性能试验研究[J].东南大学学报:自然科学版,2014,44(1):133-139.
[4]PAEGLE I,FISCHER G.Phenomenological interpretation of the shear behavior of reinforced Engineered Cementitious Composite beams[J].Cement and Concrete Composites,2016,73:213-225.
[5]ZIJL G P A G V.Improved mechanical performance:Shear behaviour of strain-hardening cement-based composites(SHCC)[J].Cement and Concrete Research,2007,37(8):1241-1247.
[6]SHIMIZU K,KANAKUBO T,KANADA T,et al.Shear Behavior of PVA-ECC Beams[J].Materials and Structures,2006,35(30):443-351.
[7]许青青.超高韧性水泥基复合材料在深受弯构件中的应用研究[D].大连:大连理工大学,2016.
[8]陈止戈,刘岳,钱国梁,等.钢筋混凝土简支深梁的试验研究[J].建筑结构,1984(1):40-45.
[9]SAHOO D R,MARAN K,KUMAR A.Effect of steel and synthetic fibers on shear strength of RC beams without shear stirrups[J].Construction and Building Materials,2015,83:150-158.