多相导电混凝土的受弯开裂自监测性能

Self-Monitoring Performance of Cracking Development of Multiphase Conductive Concrete Subjected to Bending

将结构型钢纤维(SF)、碳纤维(CF)及纳米炭黑(NCB)作为多相导电材料加入混凝土中,研究了多相导电材料对混凝土开裂后的力学性能、导电性能及裂缝扩展自监测性能的影响.建立了混凝土梁的受拉区表面电阻变化率(FCR)与裂缝张开位移(COD)之间的关系.结果表明:导电相材料的加入能够显著提高抗弯强度与弯曲韧性;多相导电材料对弯曲性能及裂缝扩展的自监测性能具有正混杂效应;电阻变化率与裂缝张开位移呈线性关系.

By adding the macro steel fiber （SF ）, th e c a rb o n f ib e r （ C F ） an d th e n a n o -c a rb o n b la c k （N C B ） intothe concrete as the multiphase conductive materials, th e in f lu en c e s of th e S F, th e CF a ncal properties and conductivity of the cracked concrete as well as on the self-monitoring development are investigated. Then, a relationship between the fractional change of the surface resistance （ F C R ）and the crack opening displacement （COD ） of th e co n d u c t iv e co n c re te b e ams is e s tab l ish e d . T h e re su l ts （ 1 ） the addition of the conductive materials can greatly enhance the flexural strength and toughness of the con-crete ;（ 1 ） the hybrid use of the NCB, the CF and the SF shows a clear pos itive hybrid effect on the f lexural beha-vior and the slf-monitoring performance of the crack development; a n d （3 ） th e re is a l in e a r re la t io n sh ip be tween the FCR and the COD.