Development of magnesium potassium phosphate cement pastes and mortars incorporating fly ash

Bilginer, Baki Aykut
Magnesium potassium phosphate cements (MKPCs) have some promising properties to be considered as an alternative to ordinary Portland cement binders. The favorable properties of these cements are high early and ultimate strength. On the other hand, they have some problems like rapid setting, high heat of reaction, high cost and poor water stability. In this study, the effect of several factors like magnesium-to-phosphate molar ratio (M/P), water-to-binder ratio (W/B) and retarder (borax) content on properties such as setting time, compressive strength and on the microstructural evolution of MKPC pastes is investigated. Also, the effect of sand-to-binder ratio (S/B) and fly ash content on properties of MKPC mortar is investigated. The setting times of the paste samples were found to be between 4 and 10 min. The compressive strengths of the pastes were about 50 MPa. The 28 d compressive strength of the highest-strength mortar, prepared with S/B = 1.25, was almost 80 MPa. This value decreased with increasing fly ash content. Also, the strength loss in water did not seem to change with fly ash replacement. TGA and SEM investigations were also performed on paste samples used to study the effects of M/P and fly ash content.


Production of fly ash-magnesium phosphate cements
Bilginer, Baki Aykut; Erdoğan, Sinan Turhan (null; 2019-05-02)
Magnezyum fosfat çimentolu (özellikle magnezyum potasyum fosfat çimentolu [MKPC]) bağlayıcılar Portland çimentosuna kısmi alternatif olabilecek sistemlerdir. MKPC yaygın olarak kalsine MgO tozu ve potasyum dihidrojen fosfat tuzu kullanılarak hazırlanır. Sulu karışımda meydana gelen asit-baz tepkimesi çok hızlı gerçekleştiğinden, bir geciktirici (boraks) de eklenir. MKPC’nin çabuk priz alma, çok hızlı dayanım kazanma ve yüksek nihai dayanım gibi geleneksel çimentolu sistemlere üstün yan...
Effect of mixture proportioning on the strength and mineralogy of magnesium phosphate cements
Bilginer, Baki Aykut; Erdoğan, Sinan Turhan (Elsevier BV, 2021-3)
Magnesium potassium phosphate cement (MKPC) has properties advantageous over ordinary portland cement such as quick setting and rapid strength gain. Although the effect of mixture proportioning on MKPC pastes has been studied, there are conflicting reports on how calcination of magnesia, parameters like magnesium-to-phosphate ratio (M/P) and water-to-binder ratio (W/B), added materials like borax and fly ash, or the addition of sand influence mineralogy and properties like setting and strength. These factor...
Development of magnesium oxalate cements with recycled portland cement paste
İçınsel, Nesim; Erdoğan, Sinan Turhan; Department of Civil Engineering (2020-10-23)
In search of lower-carbon-footprint alternatives to portland cement systems, magnesium-based cements are one of the most promising materials to investigate. Even though it is not possible to directly replace the calcium oxide in portland cement with magnesium oxide, magnesium oxide has its distinct mechanisms of forming binders with various materials. Some of the proven magnesium cements use acid-base reactions to create a binder by coupling an acid with magnesium oxide, such as the well-known magnesium pho...
Development of polycarbonate based zeolite 4A filled mixed matrix gas separation membranes
SEN, Deger; Kalıpçılar, Halil; Yılmaz, Levent (2007-10-15)
The incorporation of fillers, blending with multifunctional low molecular-weight additives and their combination are investigated as alternatives for modifying the permselective properties of polymeric gas separation membranes. For this purpose, pure polycarbonate (PC), PC/p-nitroaniline (pNA), PC/zeolite 4A and PC/pNA/zeolite 4A mixed matrix membranes were prepared by solvent-evaporation method using dichloromethane as solvent. Zeolite 4A was the filler and pNA was the low molecular-weight additive with mu...
Utilization of GGBFS blended cement pastes in well cementing
Alp, Barış; Yaman, İsmail Özgür; Akın, Serhat; Department of Cement Engineering (2012)
In well cementing, the cement slurry is exposed to the conditions far different than those of ordinary Portland cement (PC) used in construction. After placement, hardened cement paste should preserve integrity and provide zonal isolation through the life of the well. American Petroleum Institute (API) Class G cement is the most common cement type used in various well conditions. Class G cement has a high degree of sulfate resistance which makes it more stable than PC when subjected to the compulsive well c...
Citation Formats
B. A. Bilginer, “Development of magnesium potassium phosphate cement pastes and mortars incorporating fly ash,” M.S. - Master of Science, Middle East Technical University, 2018.