Temperature-induced transient creep strain in fiber-reinforced concrete

This paper presents development of temperature-induced transient creep strain in different types of concrete. To measure creep strain, concrete specimens were subjected to combined effects of heating and mechanical loading in the temperature range between 20 degrees C and 800 degrees C. The test variables included temperature, load level, rate of heating, strength of concrete and presence of fibers in concrete. Data from these tests indicate that transient creep strain constitutes a significant portion of total strain. Data also affirm that temperature range and stress level have significant influence on the magnitude of transient creep strain, specially at temperatures above 500 degrees C and stress levels of 40% or more. However, rate of heating and presence of fibers in concrete have only a moderate influence on the generated transient creep. Presence of steel fibers in normal strength concrete slightly reduce the extent of transient creep strain, while the addition of polypropylene fibers to high strength concrete leads to higher transient creep strain. Finally, data generated in tests on transient creep strain is utilized to propose temperature and stress dependent creep strain relations for different types of concrete.