Experimental study on flexural creep of self-compacting concrete reinforced with vegetable and synthetic fibers

Abstract

This article evaluates the impact of different fiber types on the flexural creep of self-compacting concretes (SCC). The study focuses on the effects of vegetable fibers (Hemp, [H] and Dis [D]) and synthetic fibers (Polypropylene [P]) on SCC. To assess the SCC, various tests such as spreading, J Ring, compressive strength, and flexural strength are conducted. The authors developed a test configuration and methodology to subject beams measuring 120 cm in length to sustained flexural stresses for 200 days. Two curing modes of the beams are also studied: total creep (beams exposed to air) and endogenous creep (beams protected from air). Moreover, the plant fibers were previously subjected to two treatments separately; the first involves immersing them in a 5% alkaline solution of NaOH (HN and DN) and the second in a solution of the polymer styrene-butadiene rubber (SBR) (HS and DS). The findings show that the treatment of vegetable fibers by SBR reveals high mechanical properties as well as a good capacity for endogenous and total creep. SCC-DS shows an increase in flexural strength of 9% and 13% with a decrease in total creep of 4% and 16% compared to SCC without fiber and SCC-DN, respectively. These results are promising for further reflection on a large scale to explore the issue of strengthening SCC with treated vegetable fibers.

Keywords:
self-compacting concrete; vegetable fibers; hemp; dis; polypropylene; styrene-butadiene rubber; flexural creep