Evaluation of Consolidation in Concrete Pavements

Evaluation of Consolidation in Concrete Pavements
Author: Daniel Stephen Lane
Publisher:
Total Pages: 18
Release: 1994
Genre: Pavements, Concrete
ISBN:

Petrographic examinations of specimens from two recently constructed concrete pavements suggested that complete consolidation of the concrete may not have been achieved. Consequently, a quantitative evaluation of the degree of consolidation in these specimens was undertaken. The pavements were of plain, jointed design with dowels for load transfer. Both projects were constructed using slip-form paving machines with spud vibrators. It was found that the entrapped void content was excessive. In both cases, the entrapped void content of the lower half of the pavement was higher than the upper half. This situation apparently occurred because the vibrators were set to ride above the preplaced dowel assemblages. In one pavement the consolidation of the upper half was adequate, but the entrapped void content of the upper half of the other pavement was also found to be excessive. The following recommendations are made: (1) During preplacement conferences and actual construction, emphasize the importance of adequate consolidation of concrete throughout the pavement, especially in the vicinity of dowel assemblages. (2) Consider alternative methods of dowel placement. Pavers with dowel bar inserters are available. (3) Investigate methods to evaluate and monitor consolidation during construction. Nuclear gauges are used for this purpose in some states although not all applications have been successful. Ultrasonic techniques show promise for this application.

Handbook on Nondestructive Testing of Concrete

Handbook on Nondestructive Testing of Concrete
Author: V.M. Malhotra
Publisher: CRC Press
Total Pages: 387
Release: 2003-12-29
Genre: Technology & Engineering
ISBN: 1420040057

Civil and structural engineering consultants engaged in quality control or investigations of hardened concrete need a comprehensive resource that explains the methods of determining strength and other performance characteristics. Handbook on Nondestructive Testing of Concrete, Second Edition answers this demand by providing a thorough analys

Initial Laboratory Studies of the Nondestructive Evaluation of Concrete Consolidation Using a Pulsed Ultrasonic Interferometer

Initial Laboratory Studies of the Nondestructive Evaluation of Concrete Consolidation Using a Pulsed Ultrasonic Interferometer
Author:
Publisher:
Total Pages: 38
Release: 1996
Genre: Nondestructive testing
ISBN:

The objectives of this study were (1) to study the feasibility of using a pulsed, swept-frequency ultrasonic interferometer in the nondestructive evaluation of the degree of concrete consolidation and (2) to find a correlation between the degree of consolidation and the ultrasonic velocity calculated from the phase slope. The system developed incorporated a pulsed ultrasonic interferometer, an oscilloscope, and a PC for automatic data logging and processing. Typical results from the ultrasonic monitoring of consolidation in fresh concrete at an early age are presented, and a correlation between the degree of consolidation and the ultrasonic velocity calculated from the phase slope is shown. The system developed was able to make ultrasonic velocity, amplitude, waveform, and frequency measurements on plastic and hardened concrete. The results suggest that void size may affect ultrasonic travel in a manner that can be differentiated by the equipment. Variations in paste development that affect the measurement of velocity abate about 12 hr after mixing. Thereafter, the system can be an accurate approach for the nondestructive evaluation of the degree of concrete consolidation. The authors recommend additional study to further refine the capabilities of the system.

Relationship of Consolidation to Performance of Concrete Pavements

Relationship of Consolidation to Performance of Concrete Pavements
Author: David Whiting
Publisher:
Total Pages: 152
Release: 1988
Genre: Concrete
ISBN:

A study was made of the influence of consolidation on properties of portland cement concrete. A model acceptance sampling plan for concrete consolidation is proposed. The plan is of the inspection by variables type and requires a sample size of eight per lot. The plan provides for buyer's and seller's risks of 5 percent. The plan was field tested in Idaho and Iowa. Field testing indicated that monitoring concrete pavement consolidation is practical and economically feasible.

Report No. FHWA-RD.

Report No. FHWA-RD.
Author: United States. Federal Highway Administration. Offices of Research and Development
Publisher:
Total Pages: 112
Release: 1973
Genre:
ISBN:

Quality Control of Concrete On-site

Quality Control of Concrete On-site
Author: David Whiting
Publisher: National Research Council
Total Pages: 68
Release: 1994
Genre: Technology & Engineering
ISBN:

This implementation package provides descriptions and evaluations of conventional concrete testing and new concrete testing. New test descriptions and evaluations include 1) microwave oven drying, 2) temperature-matched curing, 3) maturity, 4) density, and 5) pulse-velocity.