IMPACT OF SLAG CONTENT IN ALKALI-ACTIVATED SLAG CEMENT ON POROSITY OF CONCRETE

Author(s): Pavel Krivenko, Oles’ Lastivka, Igor Rudenko, Sergei Lakusta
Paper category: Proceedings
Book title: proceedings of the International RILEM Conference on Materials, Systems and Structures in Civil Engineering Conference segment on Service Life of Cement-Based Materials and Structures
Editor(s): Miguel Azenha, Ivan Gabrijel, Dirk Schlicke, Terje Kanstad and Ole Mejlhede Jensen
ISBN:978-2-35158-170-4
e-ISBN: 978-2-35158-173-5
Publisher: RILEM Publications SARL
Publication year: 2016
Pages: 28-37
Total Pages: 9
Language : English

Abstract: The paper covers results of studies on porosity, freeze/thaw resistance of alkali-activated slag
cement (AAC) concrete depending upon composition of AAC and chemical admixtures.
Freeze-thaw resistance was assessed by a number of cycles of alternate freezing/thawing in
aqueous solution of NaCl at t= - (50 ± 5) °C until 5% loss of compressive strength. This
strength loss can be attributed to accumulation of deteriorations caused by cyclic volume
deformations occurred in concrete structure in the process of ice formation. With increase of
slag content in AAC from 50 to 100% and corresponding increase of alkaline component
content a volume of open capillary pores tended to decrease with formation of more quantities
of micro- and conditionally closed pores. Effect of polyethers as admixtures was greater,
whereas, effect of polyesters was “suppressed”. Change of alkaline component from sodium
carbonate to sodium silicate in AAC resulted in increase of concrete porosity. With reduction
of volume of open capillary pores the volumes of ice formed in the AAC concrete tended to
decrease, similar to stresses which could cause changes in the AAC concrete structure, thus
“spoiling” its freeze/thaw resistance.

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