椰壳纤维泡沫混凝土弯曲性能及孔隙特性研究  

Study on flexural performance and pore characteristics of coir fiber foamed concrete

作　　者：乔聪 赵三欣 李瑞园 谢东武[3] QIAO Cong;ZHAO Sanxin;LI Ruiyuan;XIE Dongwu(Shangqiu University,Kaifeng 475000,China;College of Civil Engineering,Guangxi University,Nannning 530004,China;Department of Underground Architecture and Engineering,School of Civil Engineering,Tongji University,Shanghai 200092,China)

机构地区：[1]商丘学院,河南开封475000 [2]广西大学土木学院,广西南宁530004 [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10期25-31,共7页Concrete

基　　金：国家自然科学基金(41977227)。

摘　　要：泡沫混凝土(FC)是一种轻质、低能耗的绿色建筑材料,常用于地基回填、轻质隔墙和缓冲吸能材料。然而,抗折强度低、脆性大和容易开裂等缺点限制了泡沫混凝土的应用。通过掺入高强度、高韧性可再生天然椰壳纤维(CF)来提高泡沫混凝土的强度和韧性,增强其工程适用性。共制备了18个试样,分为6组通过三点弯曲试验研究了CF掺量对椰壳纤维泡沫混凝土(CFFC)抗弯强度、韧性、能量吸收和失效模式的影响,以及利用图像处理软件(IPP)研究了不同掺量纤维CFFC的孔隙形态、孔隙率、平均孔径和孔隙圆度。研究表明:CF可以影响CFFC的孔隙特性,改善其抗折性能。将CF从0增加到2.0%,CFFC的极限承载力从205 N增加到472 N,刚度从630 N/m增加到1830 N/m,抗折强度从0.33 MPa增加到0.73 MPa,韧性吸能从0.05 J增加到1.4 J。然而,CFFC的抗弯性能会因过量的CF而降低,建议椰壳纤维的最佳掺量为2.0%。Foamed concrete,a lightweight and low-energy green building material,is commonly used for foundation filling,lightweight partition walls,and cushioning energy-absorbing materials.However,its disadvantages,such as low flexural strength,high brittleness,and easy cracking,limit its applications.In this experiment,renewable natural coir fiber with high strength and toughness were added to improve the strength and toughness of foamed concrete,and enhance its engineering applicability.A total of 18 specimens were prepared and divided into 6 groups.The effects of coir fiber content on the bending strength,toughness,energy absorption,and failure mode of coir fiber foamed concrete were studied through three-point bending tests.Additionally,image processing software was used to study the pore morphology,porosity,average pore size,and pore roundness of coir fiber foamed concrete with different fiber contents.The results showed that coir fiber can affect the pore characteristics of of coir fiber foamed concrete and improve its flexural performance.When the coir fiber content increased from 0 to 2.0%,the ultimate bearing capacity of of coir fiber foamed concrete increased from 205 N to 472 N,stiffness increased from 630 N/m to 1830 N/m,flexural strength increased from 0.33 MPa to 0.73 MPa,and toughness energy absorption increased from 0.05 J to 1.4 J.However,the bending performance of of coir fiber foamed concrete would decrease due to excessive coir fiber,and this study suggested that the optimal coir fiber content for coir fiber is 2.0%.

关 键 词：泡沫混凝土 椰壳纤维掺量 抗折性能 微观机理 孔隙特性 

分 类 号：TU528.572[建筑科学—建筑技术科学]