短切碳纤维对混凝土孔结构及特征的影响

硅酸盐通报 ›› 2022, Vol. 41 ›› Issue (8): 2759-2766.

短切碳纤维对混凝土孔结构及特征的影响

王慧孜¹, 聂良学², 罗鑫³, 刘鹏程²

1.浙江翔翔机场工程集团有限公司,杭州 311215;
2.93125部队,徐州 221005;
3.军事科学院国防工程研究院,北京 100036

收稿日期:2022-03-03 修回日期:2022-05-23 出版日期:2022-08-15 发布日期:2022-08-30
通讯作者: 罗鑫,博士,高级工程师。E-mail:youranluo1205@yeah.com
作者简介:王慧孜(1986—),女,工程师。主要从事机场道面材料及结构方面的研究。E-mail:972447703@qq.com
基金资助:
国家人民防空办公室立项课题(RF20SC01J-S0)

Effects of Chopped Carbon Fibers on Pore Structure and Characteristics of Concrete

WANG Huizi¹, NIE Liangxue², LUO Xin³, LIU Pengcheng²

1. Zhejiang Xiang Xiang Airport Engineering Group Co. Ltd., Hangzhou 311215, China;
2. 93125 Troops of PLA, Xuzhou 221005, China;
3. National Defense Engineering Institute, Academy of Military Sciences, Beijing 100036, China

Received:2022-03-03 Revised:2022-05-23 Online:2022-08-15 Published:2022-08-30

摘要/Abstract

摘要： 为探究短切碳纤维(CFs)对混凝土内部孔结构微观特征的影响规律,制备体积掺量分别为0%、0.1%、0.2%、0.3%和0.5%的短切碳纤维增强混凝土(CFC)试件,采用压汞法(MIP)分析各组试件内部孔结构特性,并引入分形理论对孔径分形规律展开进一步探讨。结果表明:掺入适量的CFs可有效降低混凝土总孔隙量和平均孔径,且掺量为0.1%时改善效果最佳;混凝土内部孔径具有显著的分形特性,各组试件ln(W_n/r²_n)、ln Q_n曲线拟合相关系数R²均在0.996以上,斜率可作为孔表面积分形维数(D_p);随着CFs掺量的增加,D_p先减小后增大,且D_p越大,平均孔径越大,进一步验证了CFs对混凝土内部结构的改善规律。

关键词: 短切碳纤维, 混凝土, 孔结构, 孔径, 分形维数, 孔隙量, 微观特征

Abstract: For the purpose of explore the effects of chopped carbon fibers (CFs) on the microscopic characteristics of the internal pore structure of concrete, chopped carbon fibers reinforced concrete (CFC) specimens with volume content of 0%, 0.1%, 0.2%, 0.3% and 0.5% of CFs were prepared. The internal pore structure characteristics of each group of specimens were analyzed by means of mercury intrusion porosimetry (MIP), and the fractal law of pore size was further discussed by introducing fractal theory. The results show that adding an appropriate amount of CFs can effectively reduce the total porosity and average pore size of concrete, and the improvement effect reaches the best when the content of CFs is 0.1%. The inner pore size shows remarkable fractal characteristics, and the fitting correlation coefficient R² of ln(W_n/r²_n) and ln Q_n of each group specimens of concrete is more than 0.996, which means the slopes can be used as pore surface fractal dimension (D_p). The D_p decreases firstly and then increases with the increase of CFs content, and the larger the D_p is, the larger the average pore size is, which further verifies the improvement law of CFs on the internal structure of concrete.

Key words: chopped carbon fiber, concrete, pore structure, pore size, fractal dimension, porosity, microscopic characteristic

中图分类号:

TU528.58

王慧孜, 聂良学, 罗鑫, 刘鹏程. 短切碳纤维对混凝土孔结构及特征的影响[J]. 硅酸盐通报, 2022, 41(8): 2759-2766.

WANG Huizi, NIE Liangxue, LUO Xin, LIU Pengcheng. Effects of Chopped Carbon Fibers on Pore Structure and Characteristics of Concrete[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2022, 41(8): 2759-2766.

参考文献

[1] MANDELBROT B. The fractal geometry of nature[M]. New York: WH Freeman, 1982.
[2] GAO S, LI Q Y, LUO J L. Fractal characteristic of recycled aggregate and its influence on physical property of recycled aggregate concrete[J]. Reviews on Advanced Materials Science, 2021, 60(1): 663-677.
[3] 王璜琪,薄艾,王栋民,等.连续级配集料分形理论的误差分析及求解示例[J].材料导报,2021,35(s2):254-258.
WANG H Q, BO A, WANG D M, et al. Error analysis and solution example of fractal theory of continuous grading aggregate[J]. Materials Reports, 2021, 35(s2): 254-258 (in Chinese).
[4] 范小春,葛腾,梁天福.混杂钢纤维超高性能混凝土梁裂缝分形理论研究[J].硅酸盐通报,2022,41(5):1578-1588+1598.
FAN X C, GE T, LIANG T F. Study on factal theory of cracks in hybrid steel fiber ultra-high performance concrete beams[J]. Bulletin of the Chinese Ceramic Society, 2022, 41(5): 1578-1588+1598 (in Chinese).
[5] YOO D Y, KANG M C, CHOI H J, et al. Influence of chemically treated carbon fibers on the electromagnetic shielding of ultra-high-performance fiber-reinforced concrete[J]. Archives of Civil and Mechanical Engineering, 2020, 20(4): 1-15.
[6] HAN J H, WANG D B, ZHANG P. Effect of nano and micro conductive materials on conductive properties of carbon fiber reinforced concrete[J]. Nanotechnology Reviews, 2020, 9(1): 445-454.
[7] 秦昭巧,陈新杰,储洪强,等.镀镍碳纤维水泥基材料的电热性能研究[J].硅酸盐通报,2022,41(3):802-809.
QIN Z Q, CHEN X J, CHU H Q, et al. Electrothermal performance of nickel-plated carbon fiber cement-based materials[J]. Bulletin of the Chinese Ceramic Society, 2022, 41(3): 802-809 (in Chinese).
[8] KATZ A, BENTUR A. Mechanical properties and pore structure of carbon fiber reinforced cementitious composites[J]. Cement and Concrete Research, 1994, 24(2): 214-220.
[9] LIU R, XIAO H G, GENG J S, et al. Effect of nano-CaCO₃ and nano-SiO₂ on improving the properties of carbon fibre-reinforced concrete and their pore-structure models[J]. Construction and Building Materials, 2020, 244: 118297.
[10] 孟博旭,许金余,彭光.纳米碳纤维增强混凝土抗冻性能试验[J].复合材料学报,2019,36(10):2458-2468.
MENG B X, XU J Y, PENG G. Anti-freeze performance test of nano carbon fiber reinforced concrete[J]. Acta Materiae Compositae Sinica, 2019, 36(10): 2458-2468 (in Chinese).
[11] 杨虹,王海龙,王红珊,等.碳纤维轻骨料混凝土力学性能试验研究[J].建筑结构,2021,51(11):108-112+46.
YANG H, WANG H L, WANG H S, et al. Experimental study on mechanical properties of carbon fiber light-weight aggregate concrete[J]. Building Structure, 2021, 51(11): 108-112+46 (in Chinese).
[12] 张玲玲.改性碳纤维增强水泥基材料抗裂抗渗性的研究[D].南京:东南大学,2021.
ZHANG L L. Study on crack and permeability resistance of modified carbon fiber reinforced cement based materials[D]. Nanjing: Southeast University, 2021 (in Chinese).
[13] 施劲松,许金余,任韦波,等.高温后混凝土冲击破碎能耗及分形特征研究[J].兵工学报,2014,35(5):703-710.
SHI J S, XU J Y, REN W B, et al. Research on energy dissipation and fractal characteristics of concrete after exposure to elevated temperatures under impact loading[J]. Acta Armamentarii, 2014, 35(5): 703-710 (in Chinese).
[14] 王春晓,董建明,李得胜.基于孔结构分形的混杂纤维混凝土抗冻性能研究[J].硅酸盐通报,2021,40(11):3608-3616.
WANG C X, DONG J M, LI D S. Research on frost resistance of hybrid fiber reinforced concrete based on fractal theory of pore structure[J]. Bulletin of the Chinese Ceramic Society, 2021, 40(11): 3608-3616 (in Chinese).
[15] RÜBNER K, HOFFMANN D. Characterization of mineral building materials by mercury-intrusion porosimetry[J]. Particle & Particle Systems Characterization, 2006, 23(1): 20-28.
[16] 褚武扬.材料科学中的分形[M].北京:化学工业出版社,2004.
CHU W Y. Fractals in materials science[M]. Beijing: Chemical Industry Press, 2004 (in Chinese).
[17] ZHANG B Q, LI S F. Determination of the surface fractal dimension for porous media by mercury porosimetry[J]. Industrial & Engineering Chemistry Research, 1995, 34(4): 1383-1386.
[18] KAMESWARA RAO C V S, SWAMY R N, MANGAT P S. Mechanical behaviour of concrete as a composite material[J]. Matériaux et Construction, 1974, 7(4): 265-271.