Polyphosphate-modified calcium aluminate cement matrices were prepared by using aqueous solutions polluted with toxic metals as mixing water to obtain waste-containing solid blocks with improved management and disposal. Synthetically contaminated waters containing either Pb or Cu or Zn were incorporated into phosphoaluminate cement mortars and the effects of the metal's presence on setting time...

objectives to evaluate predictive value of vessel specific coronary artery calcium (cac) score in predicting obstructive coronary artery disease. patients and methods in this diagnostic test study we evaluated patients with coronary computed tomography angiography (ccta) and cac score which had been referred to two referral radiology center in tehran, iran and finally we selected 2525 patients ...

The major hydraulic phase in all the calcium aluminate cements including ciment fondue is CA (CaAl2O4). Once hydrated, it starts to form the hexagonal crystals of CAH10 and C2AH8 that depending on the time and temperature of hydration convert to the cubic crystals of C3AH6 and AH3. The nature, sequence, ...

The compositions and molecular structures of anhydrous and hydrated cements are established by using advanced solid-state nuclear magnetic resonance (NMR) spectroscopy methods to distinguish among different molecular species and changes that occur as a result of cement hydration and setting. One- and two-dimensional (2D) solid-state (29)Si and (27)Al magic-angle spinning NMR methodologies, incl...

Phosphate coating hazardous wastes originated from the automotive industry were efficiently encapsulated by an acid-base reaction between phosphates present in the sludge and calcium aluminate cement, yielding very inert and stable monolithic blocks of amorphous calcium phosphate (ACP). Two different compositions of industrial sludge were characterized and loaded in ratios ranging from 10 to 50...

Calcium aluminate cements are niche used in the refractory industry and non-structural applications for building chemistry with short return-to-service delay. The later use theses combination calcium sulfates long-term stability. By being cements, knowledge of hydration is not as extensive that Portland cement. In present paper, studied diluted suspensions a function different parameters such s...