Magnesium phosphate cement gained recognition as a chemically bonded ceramic material formed with the reaction of magnesium oxides (MgO) and phosphates (NH4H2PO4). Reactions are comparatively very fast and development of microstructure is governed by cementitious based hydrogel products. Magnesium phosphate cement is considerably a new type of material that have several good properties that may lead to its involvement in concrete sector. MPC has shown decent progress within several applications by exhibiting high early age strength, good resistance to shrinkage with exceptional bonding properties. However, since several ingredients are needed (magnesium oxide, ammonium dihydrogen phosphate, borax (retarder), fly ash), higher number of parameters are involved for optimizing this kind of material. Thus proper knowledge on optimization of these parameters become mandatory. In this study, properties of magnesium phosphate cement mortar specimens under compressive loading are examined with different mixture parameters. Molar ratios of magnesium oxides to NH4H2PO4 were diagnosed for 3 different levels whereas addition of fly ash into the binder mix was altered in different amounts. Specimens were cast into 40 x 40 x 40 mm steel molds and cured in a cabinet with 55% relative humidity. Molar ratio of 6 was found to be optimum whereas addition of fly ash limited 25% showed the highest performance under compression for 28 day results.
Anahtar Kelimeler: Magnesium phosphate cement, Compressive strength, magnesia, fly ash, optimization