Some observations on the calcium aluminate carbonate hydrates

Hydration water and microstructure in calcium silicate and aluminate hydrates

Understanding the state of the hydration water and the microstructure development in a cement paste is likely to be the key for the improvement of its ultimate strength and durability. In order to distinguish and characterize the reacted and unreacted water, the single-particle dynamics of water molecules in hydrated calcium silicates (C3S, C2S) and aluminates (C3A, C4AF) were studied by quasi-...

Preparation of a Carbonate-Free Complex Calcium Aluminate

Compounds found in portland cement are diffi cul t to prepare completely free of carbon diox ide. The difficu lty is further intensified in t he case of calcium aluminate monosulfate by t he instability of t he compound in t he course of its precipi tation from solut ion a nd t he consequent need fo r prepa ring it wi thi~l a limi ted t ime. The co mpound has been preparcd 111 a large qua nt it...

NMR characterization of hydrates formed in calcium aluminate– silica fume mixtures

Partially deuterated Ca3Al2(SiO4)y(OH)12 4y–Al(OH)3 mixtures, prepared by hydration of Ca3Al2O6 (C3A), Ca12Al14O33 (C12A7) and CaAl2O4 (CA) phases in the presence of silica fume, have been characterized by Si and Al magic-angle spinning–nuclear magnetic resonance (MAS–NMR) spectroscopies. NMR spectroscopy was used to characterize anhydrous and fully hydrated samples. In hydrated compounds, Ca3A...

Some observations on the feeding of the guinea pig

The study of particle size distribution of calcium carbonate and its effects on some soil properties in khuzestan province

ABSTRACT-This experiment was carried out to study particle size distribution (PSD) of carbonates in soils and its effect on some calcareous soil properties in Khuzestan Province, Iran. Soil samples (n=72) were collected from different regions. To evaluate the effect of carbonates on water contents at pressure head of -1500kpa and PSD of soil samples, these properties were determined before and ...