再生PET塑料骨料砂浆的弯曲韧性及阻尼特性  

Flexural toughness and damping property of recycled PET plastic aggregate mortar

作　　者：鲍聪 赵晓钦 樊伟 梁超锋 占海华[4] BAO Cong;ZHAO Xiaoqin;FAN Wei;LIANG Chaofeng;ZHAN Haihua(School of Civil Engineering,Shaoxing University,Shaoxing 312000,China;Zhejiang Jinggong Steel Building CO.,LTD.,Shaoxing 312030,China;Department of Structural Engineering,Tongji University,Shanghai 200092,China;College of Textile and Garment,Shaoxing University,Shaoxing 312000,China)

机构地区：[1]绍兴文理学院土木工程学院,绍兴312000 [2]浙江精工钢结构集团有限公司,绍兴312030 [3]同济大学建筑工程系,上海200092 [4]绍兴文理学院纺织服装学院,绍兴312000

出　　处：《复合材料学报》2023年第4期2343-2354,共12页Acta Materiae Compositae Sinica

基　　金：浙江省自然科学基金项目(LGF22 E080035);住房与城乡建设部科技研发项目(2021-K-123);绍兴市揭榜挂帅专项基金(2021 B41003)。

摘　　要：为研究再生聚对苯二甲酸乙二醇酯(PET)塑料骨料砂浆(RPAM)的弯曲韧性及阻尼特性,利用废弃PET塑料制备再生PET塑料骨料(RPA),以RPA取代率为参变量,开展了RPAM三点弯曲加载试验和悬挂梁弯曲自由振动试验,分析了三点弯曲RPAM荷载-挠度全曲线与弯曲韧性、弯曲振动一阶阻尼比与频率随RPA取代率的演变规律,并通过SEM测试RPA界面特征,分析其阻尼机制。结果表明:随RPA取代率增加RPAM延性增加,荷载-挠度曲线上升段和下降段斜率逐渐降低,初裂强度和抗弯强度降低;RPA的掺入使得RPAM破坏更具延性,初裂挠度和峰值挠度均明显增大,韧性指数I_(5)、I_(10)、I_(20)分别比普通砂浆提高4.17倍、5.65倍、5.89倍,且RPAM的剩余强度随RPA取代率增加逐渐增大;随RPA取代率增加,RPAM一阶频率降低9.0%~25.9%,阻尼比增加11.3%~58.1%;RPA与水泥基体之间的界面过渡区(ITZ)微观结构疏松,ITZ界面滑移与摩擦作用及RPA的黏性增加了RPAM的阻尼耗能;RPA最佳用量为15.5vol%~17.2vol%。In order to study the flexural toughness and damping characteristics of recycled polyethylene terephthalate(PET)plastic aggregate mortar(RPAM),the recycled PET plastic aggregate(RPA)was prepared from the wasted PET plastics.Taking RPA substitution rate as the variable,the three-point bending loading test and the suspension beam bending free vibration test on RPAM were carried out.The load-deflection curve,flexural toughness,firstorder damping ratio and frequency of RPAM with different RPA substitution rates were analyzed.Besides,the damping mechanism of RPA interface was analyzed based on the SEM test.The results show that with the increase of RPA substitution rate,the ductility of RPAM increases,the slopes of loading branch and unloading branch of loaddeflection curve gradually decrease,and the initial crack strength and flexural strength decrease.The addition of RPA makes the failure of RPAM more ductile,which increases the initial crack deflection and peak deflection significantly.The toughness indexes I_(5),I_(10)and I_(20)are 4.17,5.65 and 5.89 times larger than that of ordinary mortar,respectively.The residual strength of RPAM increases gradually as the RPA substitution rate increasing.With the increase of RPA substitution rate,the first-order frequency of RPAM decreases by 9.0%-25.9%,while the damping ratio increases by 11.3%-58.1%.The micro structure of interface transition zone(ITZ)between RPA and cement matrix is loose.The slippage and friction of the ITZ and the viscosity of RPA increase the damping energy consumption of RPAM,and the recommended dosage of RPA is in the range of 15.5vol%-17.2vol%.

关 键 词：再生PET塑料骨料砂浆 荷载-挠度曲线 韧性指数 延性 阻尼比 频率 界面过渡区 阻尼机制 

分 类 号：TU528.57[建筑科学—建筑技术科学]