高掺量粉煤灰PVA-ECC的力学性能研究及粉煤灰作用机理分析

Mechanical Properties of PVA-ECC with High Volume Fly Ash and Mechanism Analysis of Fly Ash

主要研究了高掺量粉煤灰对PVA-ECC力学性能的影响,对粉煤灰掺量分别为40%、50%、60%情况下PVAECC的抗压强度、薄板四点弯曲性能等进行试验研究,并分析了粉煤灰在ECC中的作用机理。结果表明:随着粉煤灰掺量的增加,ECC的抗压强度呈降低趋势,四点弯曲试验中ECC试件的初裂荷载和峰值荷载降低,跨中挠度增加,且裂缝宽度减小;高掺量粉煤灰下,纤维长度对ECC抗压强度和延性有较大的影响,掺12 mm纤维的PVA-ECC在保证强度的同时,可获得较高的延性和韧性。

In order to study the effect of high volume fly ash on the mechanical properties of PVA-ECC and analyze the mechanism of fly ash in ECC,four-point bending test and compressive strength test were carried out. The replacement ratio of cement with fly ash was 40%,50% and 60%,respectively. The experimental results indicate that with the increase of fly ash content,the compressive strength of ECC decreases,the initial crack load and peak load of ECC specimen in four point bending test decrease,the mid span deflection increases and the crack width decreases. Under the condition of high volume fly ash,the fiber length has a great influence on the compressive strength and ductility of ECC,and the 12 mm fiber can ensure the strength and obtain high ductility and toughness at the same time.