Modified J-Ring Test for Self-Compacting Concrete

Author(s): H. B. Dhonde
Paper category: Conference
Book Title: 8th International RILEM Symposium on Self-Compacting Concrete - SCC 2016
Editor: Kamal H. Khayat
ISBN: 978-2-35158-156-8
e-ISBN: 978-2-35158-157-5
Publisher: RILEM Publications SARL
Publication year: 2016
Pages: 133-144
Total Pages: 12
Language: English

Abstract: Passing Ability (PA) is one of the defining workability properties of Self-Compacting Concrete (SCC). It is commonly measured using the J-Ring (JR) apparatus by computing either the JR value or the ASTMJR value. Both these tests indirectly measure the PA - as the difference in heights of SCC inside-and-outside the JR (i.e. JR value), or as the difference between the un-restricted and restricted slump flows (i.e. ASTMJR value). Though the traditional JR test is a reliable method, it is cumbersome, time consuming and difficult to interpret; while the ASTMJR test, in spite of being simple, has been found to be irrational and unreliable. A new Modified J-Ring (MJR) test with little alteration to the traditional JR apparatus and testing procedure is proposed. The proposed test directly measures the PA of SCC as the ratio of the mass of concrete that has passed through the MJR to the total mass of concrete tested, thus providing a more rational, meaningful and holistic evaluation. In the present work, workability performance of various SCC mixes (with and without steel fibers) having a wide range of PA were tested to compare the traditional JR, Visual Blocking Index (VBI), ASTMJR and MJR test protocols. The study indicates that the PA assessment by ASTMJR test is inconsistent and poorly correlated with all other tests, whereas a strong correlation exists between the MJR and JR/VBI tests. Additionally, more realistic and refined PA limits are proposed for various tests based on the comparison of laboratory and field observations.

Online publication: 2016
Publication Type: full_text
Public price (Euros): 0.00