冻融循环后再生粗骨料回收钢纤维RC梁受弯性能试验研究  

Experimental study on flexural performance of steel fiber RC beams recovered from recycled coarse aggregate after freeze-thaw cycles

作　　者：李妍[1,2] 孟志颖 LI Yan;MENG Zhiying(School of Civil Engineering,Jilin Jianzhu University,Changchun 130118,China;Jilin Engineering Research Center of Cold Area Green Building Technology,Changchun 130118,China)

机构地区：[1]吉林建筑大学土木工程学院,长春130118 [2]寒地绿色建筑技术吉林省工程研究中心,长春130118

出　　处：《建筑结构》2022年第S01期1496-1501,共6页Building Structure

基　　金：吉林省科技厅重点研发项目(20200403161SF)

摘　　要：再生粗骨料钢筋混凝土梁经冻融循环后其抗弯性能各项指标均会有一定程度的下降,对严寒地区钢筋混凝土建筑物的安全性和耐久性有一定的危害,为此,将具有提高钢筋混凝土梁抗弯性能的工业回收钢纤维掺入再生粗骨料钢筋混凝土梁中,可以有效提高其抗弯性能。通过对12根再生粗骨料钢筋混凝土梁的受弯性能试验,研究了工业回收钢纤维体积率、冻融循环次数对再生粗骨料钢筋混凝土梁抗弯性能的影响。并通过分析荷载-挠度曲线,计算了工业回收钢纤维对再生粗骨料混凝土梁等效断裂韧度的影响。结果表明:再生粗骨料钢筋混凝土梁掺入一定体积掺量的工业废旧轮胎回收钢纤维之后,抗压强度和相对动弹性模量均有所提高,而且在循环冻融环境下,掺入工业废旧回收轮胎钢纤维的试件各方面性能的降低在冻融循环后表现出较小的影响。等效断裂韧度的计算得出与普通再生粗骨料钢筋混凝土梁试件相比,工业回收钢纤维粗骨料钢筋混凝土梁表现出较高的断裂韧度,并且在冻融循环作用后断裂韧度降低的幅度较小,因此工业回收钢纤维可作为有效增强再生粗骨料钢筋混凝土梁的有利材料。Recycled coarse aggregate concrete beam after freezing and thawing cycle the flexural performance indicators will be a certain degree of decline,security and durability of the reinforced concrete structures in cold region has certain harm,therefore,will have to improve the performance of reinforced concrete beam bending recycling of steel fiber mixed with recycled coarse aggregate in the reinforced concrete beam,can effectively improve the bending performance.The effects of volume ratio of industrial recycled steel fiber and number of freeze-thaw cycles on the flexural performance of recycled coarse aggregate reinforced concrete beams were studied through experiments on the flexural performance of 12recycled coarse aggregate reinforced concrete beams.By analyzing the load-deflection curve,the effect of industrial recycled steel fiber on the equivalent fracture toughness of recycled coarse aggregate concrete beams was calculated.Results show that the recycled coarse aggregate concrete beams with certain volume content of waste tyre recycling industry,steel fiber,compressive strength and relative dynamic elastic modulus are improved,and the cyclic freezing and thawing environment,mixed with industrial waste recycling tyre steel fiber specimen to reduce the performance of various aspects show the influence of the smaller after freezing and thawing cycle.Calculation of the equivalent fracture toughness compared with common reinforced concrete beam specimens of recycled coarse aggregate,industrial recovery of steel fiber reinforced concrete beam of the aggregate showed higher fracture toughness,and fracture toughness after freeze-thaw cycle effect reduce the size of the smaller,so the industrial recycling steel fiber reinforced concrete beam can be used as effective increase of recycled coarse aggregate of materials.

关 键 词：再生粗骨料混凝土 冻融循环 回收钢纤维 RC梁 受弯性能 等效断裂韧度 

分 类 号：TU375.1[建筑科学—结构工程]