Early age behaviour of self compacting concrete with polypropylene fibers and carbon nanofibers

Author(s): J. Puentes, G. Barluenga, I. Palomar
Paper category: Conference
Book title: 8th RILEM International Symposium on Fiber Reinforced Concrete: challenges and opportunities (BEFIB 2012)
Editor(s): Joaquim A.O. Barros
Print ISBN: 978-2-35158-132-2
e-ISBN: 978-2-35158-133-9
Publisher: RILEM Publications SARL
Pages: 611 - 623
Total Pages: 12
Language: English

Abstract: 
An experimental study on the performance of a self compacting concrete (SCC) with fibers, during the cement hydration process and the evolution in to a rigid material, was carried out. The aim of this study was to investigate the improvement of the hardened performance due to the use of fibers and the early age cracking control ability of fibers at two different scales: on a nano-structural level with the addition of carbon nano-fibers (CNF) and on a micro-structural level with the addition of polypropylene micro-fibers. The inclusion of nanofibers increased the flexural strength of cement based pastes although some problems concerning early age cracking emerged.
As any other concrete, SCC can exhibit problems during the very early ages after mixing, when cement hydration occurs, as shrinkage and early cracking. Although these problems arise during early ages, their effect can seriously compromise the long term performance and durability of the material.
SCC samples with and without fibers were monitored through its hardening process using several experimental techniques and considering the effect of water evaporation due to wind exposition during the setting process. The effect of the fibers and different SCC components, as nanosilica, and a high range water reducing admixture (HRWRA), was analysed. Besides, the ability of the applied components to avoid the stress development during the early ages was also evaluated. The influence of the fibers and additional components on the early age shrinkage was assessed, identifying the relationship between shrinkage and early age cracking.

Online publication: 2013
Publication Type: full_text
Public price (Euros): 0.00