REDUCTION OF AUTOGENOUS SHRINKAGE IN OPC AND BFSC PASTES WITH INTERNAL CURING

Author(s): Wyrzykowski, M. and Lura, P.
Paper category: Conference
Book title: XIII International Conference on Durability of Building Materials and Components - XIII DBMC
Editor(s): Marco Quattrone, Vanderley M. John
Print ISBN: none
e-ISBN: 978-2-35158-149-0
Publication year: 2015
Pages: 999-1005
Total Pages: 7
Language: English

Abstract: Self-desiccation occurring in low water-to-cement ratio (w/c) concretes and the resulting autogenous shrinkage may lead to early-age cracking and consequently jeopardize the durability and service life of high performance concrete elements. Among different methods developed to reduce the negative effects of self-desiccation, internal curing by means of superabsorbent polymers (SAP) recently gained a lot of attention. In this work, influence of SAP on the performance of cement pastes and mortars of w/c 0.30 prepared with Ordinary Portland Cement (OPC) or Blast Furnace Slag Cement (BFSC) is studied.

In particular, self-desiccation and autogenous shrinkage, and their reduction thanks to SAP addition, are investigated. Internal relative humidity (RH) evolution during early stages of hydration is measured using water activity sensors. It is observed that addition of SAP reduces or even practically eliminates the RH depression. As a consequence, autogenous shrinkage (measured using a linear method with corrugated tubes) is also considerably limited and even some initial expansion is promoted in the case of OPC. For BFSC, a considerable part of autogenous shrinkage is eliminated, but the remaining shrinkage is still very high. In addition, the effect of internal curing for the two types of cement, regarding the influence on hydration, mechanical properties and microstructure is also investigated.

Online publication: 2015
Publication Type: full_text
Public price (Euros): 0.00