contents of study

1) Title:

EFFECT OF WATER CONTENT ON EXPANSION AND CREEP OF CONCRETE UNDER CONSTANT MULTI-AXIAL STRESS

by S. KAWABE and T. OKAJIMA

Abstract :

The purpose of this study is to clarify the effect of water content on the thermal expansion of plain concrete under constant multi-axial stress. The thermal expansion of pre-heated concrete between 20C and 100C, under constant compressive stress including tri-axial loading in which maximum compressive stress is below one third of strength, can be concluded to be equal to the sum of elastic deformation caused by external forces and by the thermal expansion without external load. The thermal expansion of air dried and water saturated concrete is smaller than the thermal expansion of pre-heated concrete. The strain of concrete can be obtained as the sum of elastic deformation, free thermal expansion and creep strain. The creep strain of concrete at any temperature can be obtained by using the "Time Temperature Equivalence Principle."

Keywords:

Concrete, creep,water content, elevated temperature, time temperature equivalence principle, multi-axial stress, thermal expansion.

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2) Title:

THERMAL EXPANSION AND CREEP OF HIGH STRENGTH CONCRETE UNDER MULTI-AXIAL STRESS CONDITIONS

by S. Kawabe and T. Okajima

Abstract :

The purpose of this study is to clarify the thermal expansion of high strength concrete under constant multi-axial stress. The thermal expansion of air dried concrete between 20C and 100C, under constant compressive stress including tri-axial loading in which maximum compressive stress is below one third of strength, can be concluded to be equal to the sum of elastic deformation caused by external forces and by the thermal expansion without external load and creep strain. The creep strain of concrete at any temperature can be obtained by using the "Time Temperature Equivalence Principle."

Keywords:

Concrete, high strength concrete, creep, elevated temperature, time temperature equivalence principle, multi-axial stress, thermal expansion.

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