Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7885403 | Cement and Concrete Research | 2015 | 10 Pages |
Abstract
Magnesium potassium phosphate cements (MKPCs), blended with 50Â wt.% fly ash (FA) or ground granulated blast furnace slag (GBFS) to reduce heat evolution, water demand and cost, were assessed using compressive strength, X-ray diffraction (XRD), scanning electron microscopy (SEM) and nuclear magnetic resonance (NMR) spectroscopy on 25Mg, 27Al, 29Si, 31P and 39K nuclei. We present the first definitive evidence that dissolution of the glassy aluminosilicate phases of both FA and GBFS occurred under the pH conditions of MKPC. In addition to the main binder phase, struvite-K, an amorphous orthophosphate phase was detected in FA/MKPC and GBFS/MKPC systems. It was postulated that an aluminium phosphate phase was formed, however, no significant Al-O-P interactions were identified. High-field NMR analysis of the GBFS/MKPC system indicated the potential formation of a potassium-aluminosilicate phase. This study demonstrates the need for further research on these binders, as both FA and GBFS are generally regarded as inert fillers within MKPC.
Keywords
Related Topics
Physical Sciences and Engineering
Engineering
Industrial and Manufacturing Engineering
Authors
Laura J. Gardner, Susan A. Bernal, Samuel A. Walling, Claire L. Corkhill, John L. Provis, Neil C. Hyatt,