A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Modulus-Based Construction Specification for Compaction of Earthwork and Unbound Aggregate. Research Results Digest 391. National Cooperative Highway Research Program
Earthwork and unbound aggregates, collectively called compacted geomaterials, are a significant portion of the construction of pavements. Much of the distress observed in pavements, particularly in flexible pavements, can be traced to problems in geomaterials. Good pavement performance can only be assured with (1) appropriate process control to ensure the geomaterials used are similar to the ones selected, (2) proper processing of the material to ensure that the material is uniformly mixed and contains an appropriate amount of moisture before compaction, and (3) adequate compaction equipment to ensure proper density and stiffness. Currently, the nuclear density gauge is the primary tool for quality management to ensure that appropriate density. Despite the importance of moisture content at the time of compaction to the quality of the final product, not all highway agencies include moisture content in their specifications. However, measurement of moisture content and dry density does not directly tie the construction quality to mechanistic-empirical (ME) design processes where stress and modulus are key input and output parameters. In-situ nondestructive testing (NDT) devices that estimate the stiffness parameters of a constructed pavement structure are now commonly available. Such stiffness parameters provide a direct link to the pavement performance predicted through a mechanistic empirical based design process. Transformation from a density-based to a modulus-based quality assurance approach involves technical and organizational challenges that must be recognized and addressed in order to develop an efficient, practical modulus-based specification.
Modulus-Based Construction Specification for Compaction of Earthwork and Unbound Aggregate. Research Results Digest 391. National Cooperative Highway Research Program
Earthwork and unbound aggregates, collectively called compacted geomaterials, are a significant portion of the construction of pavements. Much of the distress observed in pavements, particularly in flexible pavements, can be traced to problems in geomaterials. Good pavement performance can only be assured with (1) appropriate process control to ensure the geomaterials used are similar to the ones selected, (2) proper processing of the material to ensure that the material is uniformly mixed and contains an appropriate amount of moisture before compaction, and (3) adequate compaction equipment to ensure proper density and stiffness. Currently, the nuclear density gauge is the primary tool for quality management to ensure that appropriate density. Despite the importance of moisture content at the time of compaction to the quality of the final product, not all highway agencies include moisture content in their specifications. However, measurement of moisture content and dry density does not directly tie the construction quality to mechanistic-empirical (ME) design processes where stress and modulus are key input and output parameters. In-situ nondestructive testing (NDT) devices that estimate the stiffness parameters of a constructed pavement structure are now commonly available. Such stiffness parameters provide a direct link to the pavement performance predicted through a mechanistic empirical based design process. Transformation from a density-based to a modulus-based quality assurance approach involves technical and organizational challenges that must be recognized and addressed in order to develop an efficient, practical modulus-based specification.
Modulus-Based Construction Specification for Compaction of Earthwork and Unbound Aggregate. Research Results Digest 391. National Cooperative Highway Research Program
Nazarian S. (author)
2015
18 pages
Report
No indication
English
| TIBKAT | 1982
| NTIS | 1982
| UB Braunschweig | 1982