西部盐渍土地区玄武岩纤维混凝土冻融试验及数值分析  

Freeze-Thaw Test and Numerical Analysis of Basalt Reinforced Fiber Concrete in Western Saline Soil Area

作　　者：朱飞飞 乔宏霞[1] 付勇 王新科 ZHU Feifei;QIAO Hongxia;FU Yong;WANG Xinke(School of Civil Engineering,Lanzhou University of Technology,Gansu Advanced Civil Engineering Materials Engineering Research Center,Lanzhou 730050;State Key Laboratory of High-Performance Civil Engineering Materials of Jiangsu Sobute New Materials Co.,Ltd.,Nanjing 211103)

机构地区：[1]兰州理工大学土木工程学院,甘肃省先进土木工程材料工程研究中心,兰州730050 [2]江苏苏博特新材料股份有限公司,高性能土木工程材料国家重点实验室,南京211103

出　　处：《硅酸盐学报》2024年第11期3431-3443,共13页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(U21A20150、52178216);青海省基础研究计划项目(2022-ZJ-921)。

摘　　要：西部盐渍土地区中的腐蚀离子严重影响了混凝土的耐久性,在混凝土中加入玄武岩纤维(BF)可减少初始缺陷,延缓腐蚀离子进入混凝土内部的速度,从而改善混凝土的耐久性。基于西部盐渍土环境,对不同BF掺量的玄武岩纤维混凝土(BFRC)在Na_(2)SO_(4)侵蚀和冻融循环耦合作用下的宏观性能和微观变化进行研究,并采用有限元软件ABAQUS对试验进行模拟,分析试验过程中BFRC内部应力场、应变场的变化规律。结果表明:BF的加入明显降低了混凝土在Na_(2)SO_(4)溶液-冻融循环过程中质量、相对动弹性模量、抗压强度、劈裂抗拉强度的损失率。在冻融过程中BF起到传递和分散应力的作用,使混凝土内部应力重分布提高了混凝土的抗盐冻性能,掺量0.3%(体积分数)时BFRC抗盐冻性能最佳。该有限元模型直观有效地反映出BF在混凝土冻融损伤演化过程中的重要作用。Introduction On the Loess Plateau in western China,there exists a large number of saline soils,most of which contain salts,typically of sulfate and chloride salts.Since the sulfates in saline soils are sensitive to temperature changes,they are susceptible to salt crystallization expansion and frost heave at low temperatures,which can lead to destruction of concrete structures.Salty soils and freeze-thaw environments cause concrete to be subjected to the coupled effects of simultaneous sulfate attack and freezing and expansion,which further increases the deterioration degree of concrete and seriously threatens the durability of concrete in this area.Adding fibers to concrete can effectively inhibit the plastic shrinkage cracking and improve the durability of concrete such as wear resistance,impermeability and frost resistance.Basalt fiber(BF)has excellent properties such as high strength,light weight,high temperature resistance,high elastic modulus,fracture resistance and corrosion resistance,and it is easy to disperse in concrete and has excellent cooperative work performance with concrete.Therefore,in this paper,the durability of concrete is improved by incorporating an appropriate amount of BF into the concrete to reduce the initial defects and slow down the rate of corrosive ions into the interior of the concrete.Furthermore,the effect of different BF admixtures on the relative dynamic modulus of elasticity,mass loss,compressive strength,and splitting tensile strength of concrete during salt freezing were investigated.The effect of the included BF is also clarified.Methods The concrete was prepared by P·O 42.5 ordinary Portland cement,II grade fly ash,5-20 mm continuous graded gravel and natural river sand fineness modulus of 2.83.The volume content of basalt fiber was 0%,0.1%,0.2%and 0.3%.The test was carried out with reference to the quick-freezing method in GB/T 50082—2009‘Test method for long-term performance and durability of ordinary concrete’,using HC-HDK9/Y type fast freeze-thaw cycle tester.Acc

关 键 词：玄武岩纤维混凝土 冻融循环 硫酸盐 有限元模拟 

分 类 号：TU528.572[建筑科学—建筑技术科学]