Title:
Creep Behavior of Self-Consolidating Concrete Reinforced with Hybrid Fibers
Author(s):
Nassif
Publication:
Web Session
Volume:
Issue:
Appears on pages(s):
Keywords:
DOI:
Date:
10/23/2022
Abstract:
Self-Consolidating Concrete (SCC) is one of the recent great advances in concrete technology that is gaining increasing popularity in the United States. The use of fibers with SCC to help mitigate the potential shrinkage cracking is becoming more popular in producing Fiber-reinforced Self-Consolidating Concrete (FR-SCC) for various structural applications. However, there is a need to understand the long-term behavior, such as creep and shrinkage, of FR-SCC, in comparison with SCC, under sustained loads. In particular, the effect of using of hybrid fibers as a combination of steel and polypropylene macro and micro-fibers, has not been fully addressed. There is a need to understand and identify how changes in the composition and porosity of FR-SCC, and consequently the elastic modulus, would affect its early age as well as its long-term performance. The main objective of this paper is to examine the accuracy of available prediction models for creep and shrinkage of SCC with and without fibers. The study included an experimental program to compare compression creep of SCC reinforced with hybrid fibers and creep of non-fibrous as well as mono fibrous SCC. Experimental data for creep and shrinkage were also compared to various prediction models. Results show that a combination of micro and macro polypropylene fibers cause the most reduction in shrinkage but also cause the most increase in creep strain compared to non-fiber reinforced self-consolidating concrete. Furthermore, polypropylene fibers of 1.5" length and steel crimped fibers of 1.5" length cause the highest and lowest increase in specific creep, respectively. Finally, among all models that were considered in this study, the Bazant-Baweja B3 Model is the most accurate model in predicting creep behavior for the FR-SCC mixes while CEB90-99 is the most accurate for predicting shrinkage behavior for FR-SCC.