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Impact of Sulphate Ions Content on Performance of Maleic and Acrylic Superplasticizers in Cement Paste.
- Source :
-
Materials (1996-1944) . May2021, Vol. 14 Issue 10, p2683-2683. 1p. - Publication Year :
- 2021
-
Abstract
- The paper presents test results of the impact of sulphate ions from calcium sulphates: Hemihydrate, dihydrate and anhydrite, on rheological properties and hydration heat of cement pastes with, and without, superplasticizers, derivatives of maleic (SP-2) and acrylic (SP-1) acids. It is demonstrated that cement pastes fluidity depends on superplasticizer chemical structure, and its effect is expressed by a hydrophilic coefficient. As maleic superplasticizers have flexible comb-like structure composed of a shorter backbone chain containing COO− carboxylate groups and very long side chains, cement pastes showed higher fluidity than with acrylic superplasticizer with ladder-like structure, longer backbone chains with shorter side chains. SP-1 showing lower hydrophilicity coefficient and fewer COO− groups was found to be less sensitive to increased sulphate ion content in pastes. However, with SP-2 with higher hydrophilicity, a gradual fluidity loss (increased paste viscosity) was observed. Plastic viscosity was approximately at the same level in SP-1-containing pastes. Tests showed that sulphates definitely changed polycarboxylate superplasticizers performance. A high concentration of sulphate ions reduced maleic superplasticizer efficiency. Under these conditions, SP-1 is more effective and therefore more suitable for fluidity of pastes containing higher SO42− ions content. Thus, sulphate ions concentration in the paste should be considered when selecting superplasticizer. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 19961944
- Volume :
- 14
- Issue :
- 10
- Database :
- Academic Search Index
- Journal :
- Materials (1996-1944)
- Publication Type :
- Academic Journal
- Accession number :
- 150524318
- Full Text :
- https://doi.org/10.3390/ma14102683