CHARACTERIZATION OF UHPC FREE SHRINKAGE BY A SIMPLE 2-STAGES TESTING SYSTEM

Author(s): J. Zhao, Y. Lu, Y.Y. Min and H.M. Liu
Paper category: Proceedings
Book title: Proceedings of the 2nd International Conference on UHPC Materials and Structures (UHPC2018-China)
Editor(s): Caijun Shi and Baochun Chen
ISBN: 978-2-35158-219-0
e-ISBN: 978-2-35158-220-6
Publisher: RILEM Publications SARL
Publication year: 2018
Pages: 519-531
Total Pages: 13
Language : English

Abstract: A 2-stages testing system for characterizing the free shrinkage of UHPC from setting is
proposed. In the 1st-stage, with the modified corrugated pipe specimen testing, based on
Esping & Löfgren’s model and the Dilatometer test, UHPC free shrinkage could be captured
from less than 30 minutes after mixing, and this very early shrinkage could be separated into
chemical shrinkage and autogenous shrinkage by identifying initial and final setting time on
the continuously recorded deformation-time curve. Then, 2nd-stage testing follows, i.e.
testing of autogenous & dry shrinkage under normal temperature for a specified period or of
the shrinkage during heat treatment (e.g. steam curing at 90°C for 48h). The UHPC free
shrinkage from very early, early and late stage is obtained by combining the 1st- & 2nd-stage
measurements. Comparing to many previous studies on UHPC shrinkage, this 2-stage testing
system is rather simple and does not miss any free shrinkage from setting time. So far, most
testing methods start measuring autogenous and dry shrinkage of UHPC from age of 1d or 2d
after demoulding, and the portion of autogenous or free shrinkage taking place before 1d or
2d is lost. Therefore, UHPC shrinkage could possibly be underestimated.

Online publication : 2018
Publication type : full_text
Public price (Euros) : 0.00