【作者】 简华丽；

【导师】 谢慧才；

【作者基本信息】 汕头大学 ， 结构工程， 2004， 硕士

【摘要】 碳纤维增强水泥基复合材料作为智能材料的一个重要分支其作用日益受到重视，但研究较多的仍是碳纤维水泥砂浆（CFRM），对粗骨料碳纤维混凝土（CFRC）的研究较少涉及。粗骨料的引入使碳纤维混凝土各方面性能与碳纤维水泥砂浆有较多不同。 碳纤维混凝土的压敏性是其诸多性能中一个很重要的方面。研究发现：CFRC的电阻相对变化率Δρ／ρ₀与所受外加荷载之间存在一一对应关系。本文尝试着将这一压敏原理用于交通称重系统研究。 首先，以立方体试件为研究对象，介绍了CFRC的制作工艺、试验设备。测试了碳纤维混凝土的劈拉、抗压力学性能，电学性能和循环荷载下的压敏性能，通过力学和压敏性能综合对比确定了合理的碳纤维混凝土配方。 其次，研究了环境因素对CFRC电学和压敏性能的影响，主要考虑了温度、含水量这两种环境因素。同时还研究了混凝土龄期、荷载循环次数等因素对其压敏性能稳定性的影响。结果显示，CFRC压敏性随着龄期和荷载循环的增加而渐趋稳定。 基于压敏性能的车重监测系统的研究是本文的重点。首先，提出了系统的工作原理、系统的构造设计方案。其次，进行了系统的实验室模拟试验。通过对常见车型的统计来进行荷载分级，确定了试验室荷载加载级别。用分级脉动荷载来模拟实际的交通荷载，进行了分级荷载下的压敏性能测试。着重研究了荷载沿道路横向移动时系统的稳定性问题，以及信号快速采集方法。通过优化电极布置及连接方式，取得了较好的效果。此外，还研究了车速、荷载与试件接触面积对压敏性的影响。 试验结果表明：在分级荷载的作用下，CFRC的电阻相对变化率Δρ／ρ₀的峰值也有明显的分级，不同级别的荷载对应不同级别的电阻相对变化率。这就为CFRC在实际交通监测领域的应用提供了理论支持，为交通道路行车荷载监测找到了一个具有创新性的方法。更多还原

【Abstract】 Carbon fiber-reinforced cement-based composites, one branch of the intelligent material, is arousing more and more attention in home and broad, but most of the research focalizes on the Carbon fiber-reinforced mortar (CFRM) and the research of the carbon fiber-reinforced concrete (CFRC) is rarely mentioned now.The pressure sensitivity is one the most important properties of CFRC. Previous studies have showed that , within the elastic regime, the fractional change in electrical resistance, decreased during pressure loading and in each cycle and increased during unloading in each cycle. We are tying to apply this pressure-sensitivity property to the traffic monitoring system.The mechanical property and the sensitivity of carbon fiber reinforced concrete are different from that of the carbon fiber mortar because of the coarse aggregate, so the mix proportion and the measurement method of the carbon-fiber reinforced concrete are introduced in the first chapter. The mechanical and pressure-sensitivity properties of the concrete are also involved. Reasonable fiber content is confirmed by comparing the comprehensive property of concrete with different fiber content in the same conditions.Many factors have impact on the measured resistance of carbon-fiber reinforced concrete due to its complicated mechanism of conductivity. Advanced measures have been taken to resolve the problems encountered in the resistance measurement .Influences of the environmental conditions, such as temperature and humidity, on the electrical and pressure-sensitivity prosperities of carbon-fiber reinforced concrete are introduced in the third chapter.Chapter four is the emphases of this paper. The collocation of the flaky electrode and the collection method of the DC electrical signals are listed amply in this part. Also, the weighting in motion system of strip sample based on the pressure-sensitivity is studied. The fractional electrical resistance system of carbon fiber reinforced concrete for traffic monitoring and weighting in motion was demonstrated in the laboratory for stresses from 18 KN up to 100KN. The result of the experimentation indicates that Under the Hierarchical-loading, the fractional change in the electrical resistance is also hierarchical according to the level of the load This result testify that the applying of the carbon fiber-reinforced concrete is practical.更多还原