Sentence:  The quantity of asphalt used will vary with the nature of the work. Where no <WSD>resectioning</WSD> of the road is necessary, i.e., where the new 2" layer is uniform in thickness on the picked up old surface 0-9cwt, or 100lbs. per 100 sq. ft. will be sufficient, as the binding material in the old surface works up through the new metal. 
Meaning of the word marked with <WSD> tags:  To remove material from the surface of a road in order to achieve a uniform thickness.