00740647

Component

https://doi.org/10.3141/1574-16

http://scholar.google.com...kins&publication_year=1997

Significant progress has been made in the development of a field prototype device for slipform pavers to measure the degree of consolidation of concrete during vibration. The device operates on the principle that since air is an insulator and fresh concrete is a conductor, electrical impedance measurements can indicate the release of air during the consolidation of fresh concrete. When the air is released from the fresh concrete through the process of vibration, the electrical impedance of the concrete drops in value. The device, which is based on the impedance bridge, is portable, battery-powered, noise resistant, and easy to operate. Fresh concrete has been found to be equivalent to an RC (resistor and capacitor in parallel) circuit in terms of its electrical response. Limited tests indicate that the entrapped air is released at a faster rate than entrained air, creating two distinct parts to the AC-resistance curve against time of vibration. The intersection of these two curves represents the point at which consolidation is complete. The system has a 0- to 15-V analog meter to indicate that point of completion. Project constraints did not permit the research to be completed by testing its performance on a slipform paver. However, the likelihood of commercialization has been augmented since a prototype and specifications now exist for a portable field meter.

This paper appears in Transportation Research Record No. 1574, Advances in Concrete and Concrete Pavement Construction.

English

p. 116-122

1997

Transportation Research Record

0309059739

Figures (10) ; Photos (1) ; References (7) ; Tables (1)

Air voids; Concrete pavements; Consolidation; Electrical impedance; Electrical measurement; Measuring instruments; Mechanical impedance; Paving; Prototypes; Quality control; Slip form pavers; Vibration

Bridges and other structures; Construction; Highways; I52: Construction of Pavements and Surfacings

TRIS, TRB, ATRI

Sep 8 1997 12:00AM

• APPLICABILITY AND SIGNIFICANCE OF RHEOMETRIC TESTS FOR RHEOLOGY OF FLUID AND SELF-LEVELING HIGH-STRENGTH CONCRETE
• APPLYING STATISTICAL METHODS FOR FURTHER IMPROVEMENT OF HIGH-PERFORMANCE CONCRETE FOR NEW YORK STATE BRIDGE DECKS
• CONTROL OF CRACKING WITH SHRINKAGE-REDUCING ADMIXTURES
• CRITERIA FOR OPENING EXPEDITED BONDED CONCRETE OVERLAYS TO TRAFFIC
• EFFECT OF SILICA FUME AND SUPERPLASTICIZER ADDITION ON SETTING BEHAVIOR OF HIGH-STRENGTH MIXTURES
• EFFECT OF SUPERPLASTICIZER ON SELF-COMPACTABILITY OF FRESH CONCRETE
• ELECTROMAGNETIC PROPERTIES OF CONCRETE AND THEIR SIGNIFICANCE IN NONDESTRUCTIVE TESTING
• FIBER OPTIC SENSING OF PRESTRESSED-PRISM-REINFORCED CONTINUOUS-COMPOSITE CONCRETE BEAMS FOR BRIDGE DECK APPLICATION
• FREEZE-THAW DURABILITY OF CONCRETE WITH GROUND WASTE TIRE RUBBER
• FUTURE RESEARCH TRENDS IN HIGH-PERFORMANCE CONCRETE: COST-EFFECTIVE CONSIDERATIONS
• INVESTIGATION OF FIBER-REINFORCED CONCRETE FOR USE IN TRANSPORTATION STRUCTURES
• NONDESTRUCTIVE DETERMINATION OF RESPONSE OF SHEAR KEYS TO ENVIRONMENTAL AND STRUCTURAL CYCLIC LOADING
• PERFORMANCE OF RIGID PAVEMENTS CONTAINING RECYCLED CONCRETE AGGREGATES
• RELATIVE COSTS OF VARIOUS CONCRETE PAVEMENT FEATURES
• VIBRATION STUDY FOR CONSOLIDATION OF PORTLAND CEMENT CONCRETE