高掺量粉煤灰混凝土力学性能试验研究  

Experimental Study on Mechanical Properties of High Content Fly Ash Concrete

作　　者：张兴龙 ZHANG Xinglong(Beijing Hospital of Traditional Chinese Medicine,Capital Medical University,Beijing 100010,China)

机构地区：[1]首都医科大学附属北京中医医院,北京100010

出　　处：《粉煤灰综合利用》2025年第2期49-53,共5页Fly Ash Comprehensive Utilization

摘　　要：为研究高掺量粉煤灰混凝土力学性能,制备了掺40%、50%、60%、70%不同比例粉煤灰及钢纤维0.25%、0.50%、0.75%、1%(体积分数)的混凝土试件,并将其置于模拟环境条件中进行试验。通过测试试件的抗压强度、劈裂抗拉强度、干燥收缩率及微观结构,分析高掺量粉煤灰混凝土的力学性能。结果表明:当粉煤灰掺量在40%~50%时,混凝土抗压强度下降最为明显;当钢纤维体积分数掺量为1%时,劈裂抗拉强度较未掺钢纤维混凝土增长24.4%,抗折强度达到最大值6.2 MPa,较原始强度提高了29.2%;混凝土的干燥收缩率随着粉煤灰掺量的增加呈现出先降低后升高的趋势,当掺量增加至70%时,收缩率较基准混凝土降低了12.22%,同时混凝土的孔隙率略有回升,约为8%;适当比例的粉煤灰和钢纤维掺入能够显著提升混凝土的抗拉强度、抗折强度,并优化其干燥收缩性能和孔隙结构,增强混凝土的力学性和致密性。To study the mechanical properties of high content fly ash concrete,concrete specimens containing different proportions of fly ash(40%,50%,60%,70%)and steel fibers(volume fractions of 0.25%,0.50%,0.75%,1%)were prepared and tested under simulated environmental conditions.Analyze the mechanical properties of high content fly ash concrete by testing the compressive strength,splitting tensile strength,drying shrinkage rate,and microstructure of the specimens.The results show that the compressive strength of concrete decreases most significantly when the fly ash content is between 40%and 50%;When the volume fraction of steel fibers increases to 1%,the splitting tensile strength has increased by 24.4%compared with that of the concrete without steel fibers,and the maximum flexural strength reaches 6.2 MPa,an increase of 29.2%compared to the original strength;The drying shrinkage rate of concrete shows a trend of first decreasing and then increasing with the increase of fly ash content.When the content increases to 70%,the shrinkage rate decreases by 12.22%compared to the benchmark concrete,and the porosity of the concrete slightly increases to about 8%.It can be concluded that the appropriate proportion of fly ash and steel fibers can significantly improve the tensile strength and flexural strength of concrete,optimize its drying shrinkage performance and pore structure,thereby enhancing the mechanical properties and compactness of concrete.

关 键 词：高掺量 粉煤灰 混凝土 钢纤维 力学性能 

分 类 号：TU528.01[建筑科学—建筑技术科学]