SBIR Phase I: Passive Sensor for Lifetime Monitoring of Concrete

这个小型企业创新研究第一阶段项目建议展示使用嵌入混凝土中的无源传感器来测量湿度、温度和氯化物浓度的可行性。它将为评估混凝土性能提供关键数据，从新拌或新浇筑混凝土的初始质量控制期到其使用寿命，一直到劣化和修理期。从这些传感器获得的数据应该会延长使用寿命，降低基础设施成本，并开发出更有效的补救手段。该设备将在超过一米的距离内使用射频能量进行供电和询问，返回唯一的识别号，以便数据可以与传感器位置相关联。数据将通过对设备中的一个或多个RLC天线进行频率分析来读取，这些天线的共振频率将随着周围材料的变化而改变。路面混凝土的初始强度和使用寿命以及混凝土自浇筑后的含水率对桥梁的影响很大。这种多功能传感器可以广泛使用，因为湿度和温度是硅酸盐水泥水化的主要驱动力，也是最普遍的恶化过程的基本因素，如冻融破坏、碱-集料反应、硫酸盐侵蚀或延迟钙矾石形成。

This Small Business innovation Research Phase I project proposes to demonstrate the feasibility of using a passive sensor, embedded within concrete, to measure moisture, temperature, and concentrations of chlorides. It will provide critical data for evaluating concrete performance starting with the initial quality control period of freshly mixed or freshly cast concrete, through its useful service life, to the period of deterioration and repair. Data obtained from these sensors should result in longer service life, lower infrastructure costs and the development of more effective means of remediation. The device will be powered and interrogated using radio frequency energy from a distance of over one meter, returning a unique identification number so that data can be correlated with sensor location. Data will be read by frequency analysis of one or more RLC antennas in the device, whose resonance frequencies will be altered by changes in the surrounding material. The initial strength and the service life of concrete used in roadways and its moisture content from the time that it is placed onwards significantly affects bridges. Such a multi-functional sensor can be so pervasively useful because moisture and temperature are the primary drivers for the hydration of portland cement, and are essential factors in the most prevalent deteriorative processes such as damage due to freezing and thawing, alkali-aggregate reaction, sulfate attack or delayed Ettringite formation.