After the asphalt pavement construction, often have different degrees of cracks. The emergence of various cracks will affect the quality of asphalt pavement, pavement performance to shorten the life and impact of pavement. As the saying goes "Wan harm water for the first" effective Treatment of various pavement cracks, preventing the cracks along the road surface water into the grassroots level, but also to prevent groundwater into cracks along the road surface, can significantly extend the pavement life. Causes of pavement cracks are the following. 1, due to lack of overall strength of asphalt pavement cracks which cause the rapid destruction of the road. 2, due to asphalt pavement construction defects caused by cold cracks quickly appeared. 3, reflection cracks cement stabilized crushed stone, lime, fly ash stabilized crushed stone base caused. 4, due to the aging pavement, aggregate adhesion between natural variation and the formation of cracks. Use of relevant theoretical research results, the calculations show that: 1. In Central China, North China, the daily temperature of 15 �� -20 ��, the road surface along the direction of maximum tension is 2-3Mpa above. 2. In the southern region of China, although less pavement cracking at high temperatures, but it can also be diurnal temperature reached 13-14 ��, the maximum gravitational pull pavement structure may also produce up to 1.5MPa. And on the fatigue life of pavement materials, the longer duration of action, namely to reduce the frequency, the shorter life expectancy. When the temperature is high, its life is short, that is, at high temperatures, the fatigue effect of temperature on the fatigue life of more serious than the low temperature. Thermal stress analysis results indicate that, in the semi-rigid base asphalt pavement, temperature stress is a major factor leading to surface cracking. Is cracking down progress from the road surface, crack goes wide and narrow form, not only easy to produce in the winter, summer, large temperature difference between day will lead to cracking of the pavement structure.
