FACTORS AFFECTING CRACK WIDTH OF CONTINUOUSLY REINFORCED CONCRETE PAVEMENT

Abstract

Crack width is an important factor affecting the behavior and performance of continuously reinforced concrete pavement (CRCP). Wide cracks can lead to various pavement distresses, including spalling, punchouts, and steel rupture. Various factors affecting CRCP crack width were evaluated on the basis of the width measurements of 208 transverse cracks randomly selected from a series of experimental test sections constructed in Houston, Texas. The crack widths were measured at various times and slab temperatures by using a microscope with a graduated eyepiece. It was found from a statistical analysis of the collected data that the factors that significantly affect crack width are construction season, coarse aggregate type, amount of steel, and time of crack occurrence. Thus, hot weather placement produced much wider cracks than cool weather placement. The use of siliceous river gravel resulted in cracks wider than those associated with the use of limestone, and the difference was larger at lower temperatures. The greater the amount of longitudinal steel, the narrower the crack width. Cracks occurring during the first 3 days of construction were significantly wider than those that occurred later. Finally, the effect of crack spacing on crack width was found to be insignificant.