๐”– Bobbio Scriptorium
โœฆ   LIBER   โœฆ

The chemistry of hydration of high alumina cement in the presence of accelerating and retarding admixtures

โœ Scribed by S.A. Rodger; D.D. Double

Publisher
Elsevier Science
Year
1984
Tongue
English
Weight
723 KB
Volume
14
Category
Article
ISSN
0008-8846

No coin nor oath required. For personal study only.

โœฆ Synopsis

The effect of accelerators, and in particular lithium salts and citric acid solutions, on the setting time of high alumina cement has been studied using calorimetry, solution analysis and X-ray diffraction techniques. Results are discussed with respect to the ternary CaO-AI203-H20 solubility diagram. It appears that there is a nucleation barrier to the precipitation of the main products of hydration, CAIil0 and C2AH 8 and that lithium salts function as accelerators by precipitation of a lithium aluminate hydrate which acts as a heterogeneous nucleation substrate. It is suggested that retardation by citric acid is due to the precipitation of protective gel coatings around the cement grains which impede hydrolysis or inhibit growth of the hydration products.

๐Ÿ“œ SIMILAR VOLUMES

The acceleration and retardation of set
The acceleration and retardation of set high alumina cement by additives
โœ B.R. Currell; R. Grzeskowlak; H.G. Mldgley; J.R. Parsonage ๐Ÿ“‚ Article ๐Ÿ“… 1987 ๐Ÿ› Elsevier Science ๐ŸŒ English โš– 588 KB

The set of hlgh alumlna cement (HAC) pastes may be considerably Influenced by the addltton of very small quantities of chemlcal compounds, From the measurement of settlng tlme and temperature flee. wlth a conduction calorimeter. It ls shown that both catlons and anlons have a profound effect on the

The hydration of Portland cement, C3S an
The hydration of Portland cement, C3S and C2S in the presence of a calcium complexing admixture (EDTA)
โœ N.L. Thomas; D.D. Double ๐Ÿ“‚ Article ๐Ÿ“… 1983 ๐Ÿ› Elsevier Science ๐ŸŒ English โš– 625 KB

The effect of EDTA, a calcium chelating agent, on the early hydration of Portland cement, C3Sand B-C2S has been studied by solution analysis and electron microscopy. EDTA is a retarder of cement hydration. Under normal conditions of hydration, the silica levels in solution are very low (<0.05 raM) b

Hydration of portland cement clinker in
Hydration of portland cement clinker in the presence of carbonaceous materials
โœ Dipak K. Dutta; Dipok Bordoloi; Prakash C. Borthakur ๐Ÿ“‚ Article ๐Ÿ“… 1995 ๐Ÿ› Elsevier Science ๐ŸŒ English โš– 565 KB

An investigation of the hydration behaviour of ordinary Portland cement clinker in the presence of coal, coke, and charcoal has been carried out. The physico-chemical characteristics of cement are greatly influenced by these materials. The water requirement and setting times are increased. The 1-28