Application of Microtomography to Fracture Processes in Cement-Based Materials

9523019沙阿这是缅因州大学和西北大学的联合研究项目。本研究的目的是观察水泥和砂浆小试件在单轴压缩下内部微裂纹的三维扩展。微裂纹将使用同步加速器x射线显微断层摄影术和三维图像分析技术相结合来测量。这项研究工作首次实现了水泥基材料内部裂纹的微米级定量测量。更清楚地了解断裂机制对于开发更坚固、更韧性的材料至关重要。最近，利用亚微米毫米级微细颗粒堆积的概念，已经开发出抗压强度高达800兆帕的混凝土。粒度分布(活性颗粒和非活性颗粒)对断裂韧性的影响有待研究。

9523019 Shah This is a joint research project between University of Maine and Northwestern University. The objective of the research is to observe the three dimensional growth of internal microcracks in small cement and mortar specimens loaded in uniaxial compression. The microcracking will be measured using synchrotron x-ray microtomography combined with a 3-D image analysis technique. The research work represents the first time that quantitative measurements of internal cracking of cement-based materials have been possible at micron resolution. A clearer understanding of fracture mechanisms are critical for the development of materials which are both stronger and tougher. Recently, using the concepts of microfine particle packing in the range of submicron millimeter, concrete with a compressive strength of up to 800 MPa has been developed. The influence of particle size distribution (reactive and non-reactive particles) on fracture toughness is to be investigated.