Comparative study of compressive and tensile basic creep behavior of concrete

Abstract

Due to its poor strain capacity and a low tensile strength, concrete is brittle and highly sensitive to cracking detrimental to application sustainability. Despite this well-established knowledge, the irony today is that investigations on concrete are usually limited to the compression behavior. The creep behavior that is a major concern for concrete structures is no exception to this observation. Only one reason can explain this aberration: the difficulty to perform a tensile test on cement-based materials, particularly their fixture to the loading device. This paper describes the experimental setup developed to achieve direct tensile and bending creeps. The precautions taken to obtain relevant data are described. For comparison, tensile, flexural and compressive basic creep test were conducted in parallel. Although the approach is still controversial, the basic creep strain was determined by subtracting the shrinkage strain and instantaneous strain from the total strain. Results available for specimens subjected to 50% of the strength in tension or in compression are presented. The final discussion compares the basic creep under the different types of loading.