WORKABILITY AND EARLY STRENGTH OF MAGNESIUM OXIDE BASED COMPOSITES WITH HIGH VOLUME MINERAL ADMIXTURES

3. INTERNATIONAL ULUDAĞ SCIENTIFIC RESEARCH CONGRESS, Bursa, Türkiye, 27 - 28 Temmuz 2024, ss.512-523, (Tam Metin Bildiri)

This paper investigated the fresh properties and early strengths of cementless pastes

which were produced by reactive magnesium oxide (MgO), silica fume (SF) and

ground granulated blast furnace slag (BFS). The reactive MgO was substituted with

BFS at 10% and 60% and with SF at 5% and 20% by weight of MgO. Besides, as a

reference mix, the paste having only reactive MgO as binder was used. The mini-slump

flow and rheological tests were performed to attain workability, while the early

strengths were determined by compressive and flexural strength tests on 7-day

samples. The results revealed that the flowability of pastes containing only reactive

MgO was achieved with high superplasticizer dosage and the lowest yield stress and

viscosity values were obtained for this paste. Besides, the replacement of reactive MgO

with BFS resulted in a significant improvement in the mini-slump flow diameter with

regards to the pastes having SF. Furthermore, the highest yield stress and viscosity

values were obtained for pastes incorporated with both the reactive MgO and SF.

Based on the early strength test results, the lowest early strengths were obtained from

the sample having only reactive MgO as binder and the replacement of reactive MgO

with BFS/SF caused a significant increase in strength values. However, the

incorporation of MgO and SF provided the highest early strength values.