Polyethylene glycol molecular weight as an important parameter affecting drying shrinkage and hydration of alkali-activated slag mortars and pastes

•Increasing glycol dose had minor effect on strength while significant on shrinkage.•Longer molecules reduced drying shrinkage of AAS more than short molecules.•Shrinkage was reduced thanks to surface tension decrease and porosity changes.•Ethylene glycol reduced both 2nd and 3rd peaks of AAS calori...

Full description

Saved in:
Bibliographic Details
Published in:Construction & building materials 2018-03, Vol.166, p.564-571
Main Authors: Bílek, Vlastimil, Kalina, Lukáš, Novotný, Radoslav
Format: Article
Language:English
Subjects:
Alkali-activated slag
Analysis
Chemical properties
Hydration
Mechanical properties
Molecular weight
Mortar
Polyethylene glycol
Polymerization
Porosity
Shrinkage
Shrinkage (Materials)
Strength
Surface tension
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:•Increasing glycol dose had minor effect on strength while significant on shrinkage.•Longer molecules reduced drying shrinkage of AAS more than short molecules.•Shrinkage was reduced thanks to surface tension decrease and porosity changes.•Ethylene glycol reduced both 2nd and 3rd peaks of AAS calorimetric curve.•3rd AAS calorimetric peak reduction increased with increasing molecular weight. The aim of this study was to explore the influence of ethylene glycol in a wide range of polymerization degree, i.e. from monomer (EG) up to polyethylene glycol (PEG) with molecular weight of about 35,000, on properties of alkali-activated slag mortars. Changes in molecular weight and dose of all tested glycols had only minor effect on compressive strength, while drying shrinkage was significantly affected by both these factors. EG had negligible impact on drying shrinkage, but other tested glycols reduced it significantly with PEG2000 and PEG10000 being the most effective. Such different shrinkage behavior was attributed to the changes in surface tension and pore structure. All tested glycols reduced the total heat released during the hydration and interestingly modified the heat flow depending on their molecular weight.
ISSN:0950-0618
1879-0526
DOI:10.1016/j.conbuildmat.2018.01.176