基于CNT增强ECC基压阻/压电复合型传感器（俘能器）的智能交通系统

Sensors are essential to intelligent transportation system (ITS). The techniques involving surface modification of CNT with different properties, preparation of micro (nano)-scale PZT powder, dispersion of PVA fiber, and activation of cement particles were firstly focused, and then the effect of ball milling & sonication hybrid process on compatibility & dispersion of these four ingredients with great density & addition discrepancy was studied, obtaining a novel preparation method of CNT reinforced ECC-based piezoresistive/piezoelectric composite with superior anti-cracking toughness, static/dynamic self-sensing (energy-harvesting) characters; Combination of electronic transport mechanism in features of CNT/PZT, circuit technology, and traffic detection techniques, the electrode design, static/dynamic signal sampling and extraction method of characteristic self-sensing signal of the composite were proposed; Static/dynamic self-sensing "fingerprint" and energy-harvesting properties under different spatial-temporal condition of the composite were studied; On the above basis of three aspects, the static/dynamic self-sensing mechanism and interaction mechanism of piezoresistive/piezoelectric effect of the composite were revealed combining with numerical simulation, microstructure, and electromechanical coupled analysis, and the optimization method of the piezoresistive/piezoelectric properties was proposed; Finally, the prepared composite was waterproof packaged into the sensor (energy harvester), and the pavement or bridge deck element based on these sensors (energy harvesters) was constructed, to fulfill the simultaneous monitor to traffic/structural parameters (self-powered) and health evaluation for ITS covering full frequency-domain.

传感器是智能交通系统（ITS）的基础。本课题首先研究不同性质CNT的表面修饰、微纳米级PZT粉体的合成、PVA纤维分散与水泥活化工艺，接着研究球磨/超声混杂工艺对这四种密度差异大、掺量不同组分相容分散性的影响，获得具有优异抗裂韧性、静/动态感知（俘能）特性的CNT增强ECC基压阻/压电复合材料的制备方法；结合CNT/PZT的电子输运机理、电路技术与交通传感技术，提出复合材料的电极设计、静/动态信号采集与特征感知信号提取方法；研究复合材料在不同时空条件下的静/动态感知"指纹"与俘能性能；在上述三方面基础上，结合数值模拟、微观观察和机电耦合分析，揭示复合材料静/动态感知性能的产生机理、压阻/压电效应相互作用机理，并提出感知/俘能性能优化方法；最终将该复合材料防水封装成传感器（俘能器），构建基于该传感器（俘能器）的路面或桥面单元，实现涵盖全频域ITS交通与结构参数的同步监测（自供能）与评估。

传感器是智能交通系统（ITS）的基础，水泥基传感器因在服役期间不会损害现有混凝土路面或桥面的结构性能，具有相容耐久性好、维护方便及长寿命等特点而得到广泛应用。然而现有水泥基传感器多为单结构型传感器，仅能对道路或桥梁结构性能参数变化的探测，不能对车流量、车速、车型、车重量等交通流参数同步探测。本项目组合CNT的表面修饰与超声活化、微纳米级PZT粉体的溶胶-凝胶合成及共混模压等工艺制备出一种CNT增强水泥基压阻/压电复合材料(CNT/PZT/CC)，并将该复合材料防水封装成压阻/压电复合型传感器。结合CNT/PZT电子输运机理、电路设计及静/动态特征感知信号提取技术等，研究了该复合型传感器的不同荷载大小及频率状态下静/动态电学感知能力。这为实现涵盖全频域ITS交通与结构参数的同步监测与评估提供了可能。.关键数据：.1. 结合Fenton试剂超声或UV/Fenton修饰法，获得不显著改变CNT表面电学特性的CNT功能修饰及良好分散工艺；.2. 利用溶胶-凝胶法、溶胶-水热法，并结合正交实验优化方法获得最佳压电性能的纳米级钙钛矿晶型PZT粉体制备方法，相应PZT压电陶瓷、CNT/PZT/CC的压电常数d33分别为50.6pC/N、38.5pC/N。.3. 通过掺杂碳酸锶有效抵消PZT陶瓷片煅烧过程产生的收缩应力，大幅提升PZT片的压电性能（d33=123.0pC/N、相对介电常数ζr=5.35）；相应PZT、温石棉纤维与硫铝酸盐水泥混杂复合材料封装传感器在不同冲击荷载大小及频率的电荷响应情况线性度，灵敏度，重复度分别为2.4%、1.5、3.42%。.4. 利用有限元软件对水泥基压电复合材料（PCM）传感器圆片分别进行了静力特性、模态特性、谐响应特性、瞬态动力特性进行了力-电耦合场模拟分析；并以最少材料用量为优化目标进行了PCM优化设计，得出PCM片最佳半径、厚度分别为5.07mm、0.762mm。.科学意义：.研制了一种与混凝土路/桥交通结构单元相容耐久性佳，又能对其交通与结构参数进行同步检测的复合型传感器，在ITS传感系统中具有良好应用前景。