碳纤维长度对硬化水泥净浆微波性能的影响

Effects of Carbon Fiber Length on Microwave Behavior of Hardened Cement Paste

摘要:

针对不同长度的碳纤维改性硬化水泥净浆（CFRC），分析了碳纤维长度对其力学性能、介电性能和微波性能的影响规律，揭示了碳纤维长度对CFRC微波性能的影响机理。结果表明：CFRC的抗压强度和抗折强度随着碳纤维长度的增加而先增大后减小，当碳纤维长度为1 mm时，材料的力学性能最优；CFRC对电磁波的损耗机制与碳纤维长度有关，当纤维长度为1、9、12 mm时，损耗以反射为主，当纤维长度为6 mm时，损耗以吸收为主；CFRC对电磁波的反射归因于阻抗不匹配，吸收则归因于偶极极化、弛豫极化和空间电荷极化。

Abstract:

Carbon fibers， with different lengths， were used to modify the cement paste. The effects of carbon fiber length on the microwave behavior of carbon fiber-reinforced cement paste（CFRC） were studied by analyzing how the length affects the mechanical， dielectric， and microwave behavior. The results show that the compressive strength and flexural strength of CFRC increase first and then decrease with increasing carbon fiber length， such that the highest strengths are obtained at a length of 1 mm. The electromagnetic interference shielding mechanism of CFRC is dependent on carbon fiber length： the reflection is dominant at lengths of 1， 9， 12 mm， while absorption is dominant at a length of 6 mm. The reflection of CFRC to electromagnetic waves is due to the mismatch of impedance， while the absorption of electromagnetic waves is due to dipolar polarization， relaxation polarization， and space-charge polarization.