混杂玄武岩纤维混凝土孔隙结构及抗冻性  

Pore structure and frost resistance of mixed basalt fiber concrete

作　　者：邵善庆 龚爱民 罗加辉 王福来 黄逸尔 金镯 雍康 SHAO Shanqing;GONG Aimin;LUO Jiahui;WANG Fulai;HUANG Yi’er;JIN Zhuo;YONG Kang(College of Water Resources,Yunnan Agricultural University,Kunming 650201,China)

机构地区：[1]云南农业大学水利学院,昆明650201

出　　处：《水力发电学报》2025年第2期116-124,共9页Journal of Hydroelectric Engineering

基　　金：云南省教育厅科学研究基金项目(2022Y286)。

摘　　要：玄武岩纤维粉煤灰混凝土符合绿色、经济发展理念,为提高其工程实际应用的可靠性,本文研究了不同玄武岩纤维长度(6、12、18 mm)单掺和混杂条件下,通过粉煤灰与水泥水化过程形成的孔隙、孔隙物相分布及分形维数,探究了玄武岩纤维粉煤灰混凝土孔隙结构表征及其抗冻性。研究结果表明,在300次冻融循环后,粉煤灰混凝土冻融损伤程度由大到小排序为:未掺玄武岩纤维、单掺玄武岩纤维、混杂玄武岩纤维。从孔隙结构表征来看,玄武岩纤维掺入细化了孔隙,即最大孔隙直径和孔隙率减小,从孔隙物相分布及分形维数来看,单掺孔隙主要集中在纤维的周围,使得内部孔隙形成线型集中分布,易造成冻胀应力集中,而混杂孔隙集中的现象减少,其微小孔隙分散效应有利于减小冻胀应力作用,同时粉煤灰延后水化微填充作用改善了孔隙结构,纤维的“桥接”作用阻止了孔隙径向裂隙的进一步发展,从而提高了混凝土的抗冻性。Basalt fiber fly ash concrete conforms to the concept of green and economically viable development.To improve the reliability of its practical application in engineering,this paper presents a study on the characterization of its pore structure,frost resistance by the formation of pores,pore physical phase distribution,and fractal dimension,through the hydration process of fly ash and cement under the conditions of different basalt fiber lengths(6,12,and 18 mm)in single mixing and blending scenarios.The results show that after 300 freeze-thaw cycles,the degree of freeze-thaw damage to fly ash concrete from high to low is unadulterated basalt fiber,single-adulterated basalt fiber,and mixed-adulterated basalt fiber.From pore structure characterization,basalt fiber admixture refines the pore space,that is,the maximum pore diameter and porosity both are reduced.From pore phase distribution and fractal dimension,the pore space of single admixture is mainly concentrated around the fiber,so that the internal pore space forms a linear concentrated distribution,causing the concrete to be prone to frost stress concentration.In the blending case,pore concentration is reduced significantly,and the small pore dispersion effect is conducive to reducing the role of frost stress.The fly ash component improves the pore structure through delaying the hydration micro-filling effect,and the fibers’bridging effect prevents radial cracks in the pore space from further development,thus improving the frost resistance of concrete.

关 键 词：玄武岩粉煤灰混凝土 单掺 混杂 孔隙结构表征 抗冻性 

分 类 号：TU528[建筑科学—建筑技术科学]