椰子纤维泡沫混凝土静动态力学性能研究  

Study on static and dynamic mechanical properties of coconut fiber foamed concrete

作　　者：薛苗苗 刘巧会 刘周强 谢东武[3] XUE Miaomiao;LIU Qiaohui;LIU Zhouqiang;XIE Dongwu(Zhengzhou Technology and Business University,Zhengzhou 451450,China;School of Civil Engineering,Guangzhou University,Guangzhou 510006,China;Department of Underground Architecture and Engineering,School of Civil Engineering,Tongji University,Shanghai 200092,China)

机构地区：[1]郑州工商学院,河南郑州451450 [2]广州大学土木工程学院,广东广州510006 [3]同济大学土木工程学院地下建筑与工程系,上海200092

出　　处：《混凝土》2024年第12期57-64,共8页Concrete

基　　金：国家自然科学基金(51568007)。

摘　　要：泡沫混凝土(Foamed Concrete,简称FC)存在明显的强度低、韧性差的问题,椰子纤维(Coir Fiber,简称CF)可用于改善其脆性、提高强度和吸能性能,拓宽其工程应用范围。本研究制备了4组试样,分别通过静态压缩试验和3种气压(0.20 MPa、0.25 MPa、0.30 MPa)下的霍普金斯压杆(Split Hopkinson)冲击试验探究了椰子纤维掺量(0、1.0%、1.5%、2.0%、2.5%)对泡沫混凝土失效形态、动静态抗压强度、静态荷载-位移曲线、动态应力-应变行为、吸能性能的影响。结果表明:CF含量小于1.5%时,静态抗压强度和压缩吸能分别达1.51 MPa、94.87 J。CF含量为1.5%时,动态抗压强度分别达到2.27 MPa(动态气压:0.20 MPa)、3.18 MPa(动态气压:0.25 MPa)和4.21 MPa(动态气压:0.30 MPa)。动态气压为0.20 MPa、0.25 MPa和0.30 MPa时的吸能峰值分别为8.9 J(CF含量2.0%)、14.9 J(CF含量1.5%)、22.4 J(CF含量1.5%)。但当CF掺量过量时,泡沫混凝土的静态压缩与动态冲击吸能性能反而下降。适量的CF能显著改善泡沫混凝土的静力与动力性能,静态压缩和动态冲击下试样的塑性随纤维掺量增加而明显提高,本试验综合最佳的纤维剂量为1.5%。Foamed Concrete(FC)has obvious problems of low strength and poor toughness.Coir Fiber(CF)is a natural material with high tensile strength and excellent toughness,so it can be used to improve the brittleness,strength and energy absorption properties of foam concrete,and broaden its engineering applications.In this study,four sets of specimens were prepared and tested by static compression test and Hopkinson's compression bar impact test at three impact air pressures(0.20 MPa,0.25 MPa and 0.30 MPa),respectively.Hopkinson impact tests at three impact air pressures(0.20 MPa,0.25 MPa and 0.30 MPa)were conducted to investigate the effects of coconut fiber admixture(0,1.0%,1.5%,2.0% and 2.5%)on the failure modes,dynamic and static compressive strengths,static load-displacement curves,dynamic stress-strain behaviors,and energy-consuming properties of the foam concrete.The results showed that the static compressive strength,modulus of elasticity,peak stress,residual stress,and compression energy absorption at a CF content of less than 1.5%were up to 1.51 MPa,respectively.When the CF content is 1.5%,the dynamic compressive strength reaches 2.27 MPa(dynamic air pressure:0.20 MPa),3.18 MPa(dynamic air pressure:0.25 MPa)and 4.21 MPa(dynamic air pressure:0.30 MPa).Dynamic air pressures of 0.20 MPa,0.25 MPa and 0.30 MPa,the peak dynamic energy absorption was 8.9 J(2.0%CF content),14.9 J(1.5%CF content),and 22.4 J(1.5%CF content),respectively.However,the static compression and dynamic impact energy absorption properties of the foam concrete decreased when the CF dosage was too much.Moderate CF amount can significantly improve the static and dynamic properties of foam concrete,and the plastic properties of specimens under static compression and dynamic impact increased significantly with the increase of fiber admixture,and the optimum level of this test was reached at a CF content of 1.5%.

关 键 词：泡沫混凝土 椰子纤维掺量 静态压缩性能 动态冲击性能 吸能性能 

分 类 号：TU528.572[建筑科学—建筑技术科学]