When paving the upper and lower layers in layers at the grass-roots level, the interval should be controlled within 24 hours, and the upper layer should be paved continuously with paver. When the upper and lower layers cannot be constructed continuously, the first layer of mixture shall be closed for a long time. The construction temperature of ordinary asphalt binder shall be determined according to the viscosity-temperature curves measured at 135℃ and 175℃ specified in Table 5.2.2- 1.