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http://dx.doi.org/10.5345/JKIBC.2017.17.3.211

Tests on Magnesium Phosphate Composite Mortar Mixtures with Different Molar Ratios of MgO-to-KH2PO4  

Yoon, Hyun-Sub (Department of Architectural Engineering, Kyonggi University Graduate School)
Lee, Kyung-Ho (Department of Architectural Engineering, Kyonggi University Graduate School)
Yang, Keun-Hyeok (Department of Plant.Architectural Engineering, Kyonggi University)
Publication Information
Journal of the Korea Institute of Building Construction / v.17, no.3, 2017 , pp. 211-217 More about this Journal
Abstract
The objective of this study is to seek a reliable mixture proportion for magnesium potassium phosphate composite(MKPC) mortars with a near-neutral pH value (below 9.5) and a relatively good compressive strength exceeding 30MPa. The main parameter selected was the molar ratios($M_{mp}$) of $MgO-to-KH_2PO_4$ which varied from 30.4 to 3.4. The setting time of the MKPC mortars tended to shorten with a decrease in $M_{mp}$ value. With regard to the strength development ratio normalized by the 28-day strength, the ranges measured in the mortars with an $M_{mp}$ below 7.9 were 50~61% at 1 day and 60~73% at 3 days, indicating a highly rapid early-strength development. With a decrease in $M_{mp}$, the formation of struvite-K crystal identified as a primary hydration product increased, which led to the decrease of the macro-capillary pores in micro-structures. For achieving the targeted requirements for pH value and compressive strength, the $M_{mp}$ needs to be selected as below 5.1.
Keywords
magnesium-potassium phosphate composite; compressive strength; pH; molar ratio;
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Times Cited By KSCI : 6  (Citation Analysis)
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