00676697

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http://onlinepubs.trb.org...trr/1994/1458/1458-014.pdf

https://scholar.google.co...sard&publication_year=1994

An air-entrained, high-strength concrete was prepared in a precasting plant to evaluate the effect of initial heat treatment and subsequent outdoor storage on concrete characteristics. One set of standard specimens was cured in lime-saturated water at 23 deg C until testing. Another set of specimens and a large panel were heat cured on a steel bed heated by 50 deg C water circulating underneath it. Heating began 6 hr following concrete casting and lasted for 8 hr. Heated concrete remained on the bed for an additional 6 hr before demolding; it was then cured indoor at 15 deg C until the age of 7 days before outdoor storage. Investigated properties included temperature rise, compressive, splitting tensile, and flexural strengths, modulus of elasticity, chloride ion permeability, and frost durability. Mechanical properties were evaluated at 1, 4, 28, 91, and 365 days. Test results indicate that the investigated concrete can secure high early strength without early heat curing. Initial heating increased compressive strength; however, such heat treatment coupled with subsequent outdoor storage had a deleterious effect on ultimate strength, especially for concrete from the precast panel where initial peak temperature was 56 deg C, compared with 42 deg C for accompanying heated specimens. Maximum reductions in compressive, splitting tensile, and flexural strengths and modulus of elasticity of concrete subjected to early heat curing and subsequent outdoor storage compared with standard-cured specimens were approximately 15, 35, 40, and 15 percent, respectively. Regardless of curing history, the concrete exhibited excellent frost durability. Mercury intrusion porosimetry of 1-yr old samples demonstrated that heated concrete had greater porosity than standard-cured concrete and higher concentrations of pores with 1-5 micrometer diameter. That was confirmed by microscopical examination; however, no particular increase in microcracking in the paste or transition zone of heated concrete, as compared with moist-cured concrete, was observed.

This paper appears in Transportation Research Record No. 1458, Concrete Research. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved

01401262

English

p. 91-98

1994

Transportation Research Record

0309060656

Figures (7) ; Photos (2) ; References (18) ; Tables (2)

Air entrained concrete; Chlorides; Compressive strength; Concrete; Flexural strength; Freeze thaw durability; Frost susceptibility; High strength concrete; Metal heating; Modulus of elasticity; Permeability; Physical properties; Pore size distribution; Porosity; Tensile strength

Concrete properties; Heat treatment

Highways; Materials; I32: Concrete

TRIS, TRB

Apr 28 1995 12:00AM

• ADDITION OF CLASS C FLY ASH TO CONTROL EXPANSIONS DUE TO ALKALI-SILICA REACTION
• DEVELOPMENT OF CONCRETE DURABILITY SPECIFICATION AND RATINGS IN FLORIDA
• EFFECT OF CURING ON DURABILITY OF FLY ASH CONCRETE
• EFFECT OF NATURAL POZZOLAN ADDITION ON EXPANSIONS CAUSED BY ALKALI-SILICA REACTION
• EVALUATION AND COMPARISON OF THE PHYSICAL PROPERTIES OF FIBRILLATED POLYPROPYLENE FIBER-REINFORCED CONCRETES
• IMAGE ANALYSIS OF PORTLAND CEMENT CONCRETE AND ASPHALT CONCRETE PAVEMENTS USING SCANNING ELECTRON MICROSCOPE IMAGES (WITH DISCUSSION AND CLOSURE)
• INFLUENCE OF LOADING TYPE, SPECIMEN SIZE, AND FIBER CONTENT ON FLEXURAL TOUGHNESS OF FIBER-REINFORCED CONCRETE
• INTERPRETATION OF ACCELERATED TEST METHOD ASTM P214 TEST RESULTS
• MECHANICAL PROPERTIES OF LIGHTWEIGHT CONCRETE INCORPORATING RECYCLED SYNTHETIC WASTES
• NONDESTRUCTIVE IDENTIFICATION OF INTERNALLY DAMAGED AREAS OF CONCRETE BEAM USING THE SPECTRAL ANALYSIS OF SURFACE WAVES METHOD
• OPTIMIZATION OF ROLLER-COMPACTED CONCRETE FOR LOCAL APPLICATION
• PERFORMANCE CHARACTERISTICS OF MONOFILAMENT POLYPROPYLENE FIBER-REINFORCED CONCRETE
• PREDICTION OF CREEP EFFECT IN SEGMENTAL CONCRETE BRIDGE CONSTRUCTION
• RECYCLING CONTAMINATED SPENT BLASTING ABRASIVES IN PORTLAND CEMENT MORTARS
• STABILIZATION AND SOLIDIFICATION OF CONTAMINATED SOILS AND SLUDGES USING CEMENTITIOUS SYSTEMS: SELECTED CASE HISTORIES
• SYSTEM OPTIMIZATION OF FAILURE, CONSTITUTIVE MODELING, AND STRENGTHS OF CONCRETE AND OTHER GEOLOGICAL MATERIALS USING GENETIC ALGORITHM
• USE OF MATURITY AND PULSE VELOCITY TECHNIQUES TO PREDICT STRENGTH GAIN OF RAPID CONCRETE PAVEMENT REPAIRS DURING CURING PERIOD