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The cement concrete pavement is one of the most important form of the pavement structure, which is widely used in the road at all levels. At present, with the rapid development of transport, the cement concrete pavement diseases increase, which seriously affectes the using performance of the way and the traveling quality of the vehicle, and has brought about tremendous losses to the national economy. Research and practice shows that develop the excellent crack repair materials is an effective way to solve these problems.Based on the extensive research for the cement concrete pavement cracks, and with the existing results, this paper use the silica fume as a modifier and the ultra-fine cement as a matrix material, developed a new type of pavement crack repair material. In order to study the performances of the new type crack repair material, this research began from the view point of rheological, detailedly analysed the effect of MRCRM (modified ultra-fine cement repair material) rheology to its working and filling capacity, and has brought forward the MRCRM mix design plan based on rheology and working capacity. And then, on the foundation of this mix design plan, the compared cement paste and five kinds of modified cement paste were made, their working capacity, mechanical properties and durability were systematically tested, through which the impact of the law of mix design parameters to the performances of the modified cement paste could be revealed, then the best mixing proportion with consideration of all MRCRM performances was obtained. Finally, using the analytical tools of XRD, SEM and hydration heat test, the modification mechanism of silica fume to MRCRM performances was analysed through the view point of hydration process and microstructure, and the correlation between microstructure and macro-road performance were revealed.
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