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高温后风积沙混凝土力学性能与微观结构试验研究

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本文将0%、10%、30%、50%的风积沙等质量替代普通河砂制备成风积沙混凝土,对其在温度20、200、400、600、800 ℃作用下的外观形貌变化、质量损失情况、抗压强度、抗折强度进行了试验研究;通过折压比的方法分析了风积沙混凝土在不同温度和不同风积沙掺量下力学性能的演变;通过扫描电子显微镜(SEM)研究了不同温度作用下风积沙混凝土内部微观结构的演化过程,并对微观结构机理进行了分析。结果表明:适量风积沙的掺入可以增加水化产物,优化混凝土的孔隙结构,减小混凝土内部界面过渡区厚度,使混凝土内部结构更密实,力学性能得以提升,并能延缓高温作用后混凝土裂缝与孔隙的生成;然而,风积沙掺量过多则会起到相反的效果,使高温后混凝土力学性能下降。本研究可为风积沙混凝土的应用及高温后风积沙混凝土结构的评定提供依据。
Experimental Study on Mechanical Properties and Microstructure of Aeolian Sand Concrete after High Temperature
In this paper,0%,10%,30%and 50%of aeolian sand were used to replace ordinary river sand to prepare aeolian sand concrete.The appearance change,mass loss,compressive strength and flexural strength of aeolian sand concrete at 20,200,400,600 and 800 ℃ were studied.The evolution of mechanical properties of aeolian sand concrete at different temperatures and different aeolian sand content was analyzed by flexural-compressive ratio.The evolution process of the internal microstructure of aeolian sand concrete under different temperatures was studied by scanning electron microscope(SEM),and the microstructure mechanism was analyzed.The results show that the appropriate amount of aeolian sand can increase the hydration products,optimize the pore structure of concrete,reduce the thickness of interfacial transition zone in concrete,make the internal structure of concrete more compact,improve the mechanical properties,and delay the formation of cracks and pores in concrete after high temperature.However,too much aeolian sand will have the opposite effect,which will reduce the mechanical properties of concrete after high temperature.This study can provide a basis for the application of aeolian sand concrete and the evaluation of aeolian sand concrete structure after high temperature.

aeolian sand concretehigh temperaturemechanical propertymicrostructuremicroscopic mechanismmodel fitting

赵燕茹、龙思睿、白建文、刘明

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内蒙古工业大学,土木工程学院,呼和浩特 010051

内蒙古工业大学,资源与环境工程学院,呼和浩特 010051

保定市水利局西大洋水库事务中心,保定 072350

风积沙混凝土 高温 力学性能 微观结构 微观机理 模型拟合

2024

硅酸盐通报
中国硅酸盐学会 中材人工晶体研究院

硅酸盐通报

CSTPCD北大核心
影响因子:0.698
ISSN:1001-1625
年,卷(期):2024.43(9)