本文利用碳纤维导电水泥基复合材料(CFRM)的压敏特性制成应变传感器,并研究了CFRM应变传感器在养护期间和养护完成后的电阻稳定性。试验结果表明,CFRM应变传感器的电阻在养护初期增长迅速,然后逐渐变慢,养护结束后很长一段时间内持续呈线性增长;此外,CFRM的电阻对温度很敏感,在降温0.105℃/h的过程中,电阻的变化率为2.027Ω/h;在100 h左右时间里,两个应变传感器的电阻差基本稳定在750Ω左右,拟合电阻变化率约为单个应变传感器电阻变化率的1/60,从而证明带补偿的CFRM应变传感系统可以补偿掉龄期和温度对CFRM应变传感器的影响,测量结果具有较好的稳定性。
Strain sensors were made of carbon fiber reinforced conductive cement-based material(CFRM) due to its piezoresistive phenomenon.The resistance stability of CFRM strain sensors was studied during and after their curing age.Results show that the resistance of CFRM strain sensors grows rapidly at the beginning of curing age,and then slowly.After the curing age,the resistances sustain linear growth in a long period.Resistance of CFRM is sensitive to temperature.When getting 0.105 ℃/h decline,the resistance change rate is 2.027 Ω/h.In about 100 h,the resistance difference of two strain sensors basically stable at 750 Ω and the resistance change rate is 1/60 of that of a single strain sensor.So that the CFRM strain measure system with compensation can alleviate the impact of curing age and temperature,has better stability.