10-06-2017, 07:12 AM
Abstract
Results of a 2-yr study of cause-effect relationships involved in roughness of concrete pavements are reported. Data were derived both from analog traces obtained with a profilograph in each wheelpath of randomly selected pavements within hours after placement, and from qualitative observations of placement methods. Construction sampled consisted of 184 sections of one - and - two - lane pavements built under 62 different contracts with seven different form-type finishing machines and three different slip-form pavers. Statistical analysis was held to a minimum because of uncontrolled interactions; however, five factors were found to be common and outstanding significant throughout the contracts studied. High roughness was related (1) to backing up of the last finishing machine, (2) to absence of a float, (3) to use of less than three screeds, (4) to use of a crown section, and (5) to lane-at-a-time paving. Eigh other construction phenomena producing roughness, common to many projects but found less frequently than the five just listed, are also covered in some detail. (Author)