01648586

Monograph

http://www.trb.org/Main/Blurbs/176497.aspx

The level of in-place density (also expressed as air voids content) attained by mixture compaction during construction plays a major role in achieving satisfactory long-term pavement performance. At present, there is no standard on how agencies should measure and set criteria for in-place pavement density. Most agencies have developed their own methodologies and acceptance criteria based on past practices and experiences. The result is that widespread variability exists nationally with regard to the methods of measuring in-place density, test locations in a paving lane, frequency of tests, specified density levels, as well as how measured data are applied against the specified minimum acceptance criteria. This report presents a critical analysis of the current state of knowledge and existing agency practices to measure and specify the in-place density of asphalt pavements. Based on the results of this project, areas in which improvements in the state-of-the-practice should be considered are the following: quality control and acceptance activities should be consistently performed for projects; training for all personnel is a key need; frequency of testing is highly variable and should be standardized within specific classes of project; density testing should be done for all projects, regardless of size; and both a minimum and maximum percent density should be specified. In addition, absorption evaluation of core samples should be standard for all testing if cores are obtained from the project; testing for maximum theoretical specific gravity should be performed during mix design and plant production of the mix; established standard procedures for use of non-destructive testing gauges should be followed; adequate testing should be performed to properly evaluate all material placed and test frequencies should take into account observed variations in the product to ensure a robust testing plan; a vacuum drying procedure for all cores should be followed; roller management using intelligent compaction should be used to ensure consistency of roller patterns; and joint sealers should be required for all longitudinal joints.

Project 20-07/Task 382

English

66p

2017

NCHRP Research Report

9780309446501

Digital/other

Bibliography; Figures; Tables

Air voids; Asphalt pavements; In place density; Pavement performance; Performance based specifications; Quality assurance; Quality control

Highways; Materials; Pavements

TRIS, TRB, ATRI

Oct 13 2017 12:01PM