Use this URL to cite or link to this record in EThOS:
Title: Crystal structure of tricalcium silicate and cobalt mercury thiocyanate.
Author: Jeffery, James William.
ISNI:       0000 0001 3589 7581
Awarding Body: Birkbeck (University of London)
Current Institution: Birkbeck (University of London)
Date of Award: 1950
Availability of Full Text:
Access from EThOS:
The importance of Tricalcium Silicate (3CaO. SiO2 ) arises from its occurrence in Portland Cement. Portland Cement is manufactured by the sintering in a rotary kiln of a mixture usually of limestone and clay. The final product is such that the oxides CaO, MgO, Si02,1-1l203 and Fe203 together account for from 95-99-5% of the whole. Tornebohm, examining the clinker of Portland cement under the microscope, distinguished four components, the most important of which he named 'Alite'. Towards the end of the 19th century, Le Chatelier showed that it had the probable formula 3Ca0., Si02. The controversy which subsequently arose over the question, "What is Alite? " has lasted until the present day. Bogue, in his recent book (1947) has summarised the main features of this controversy. Although he gives a reference in a footnote (pg. 116) to one paper since 1931 on this subject, he considers that the controversy had ended by that date and quotes Guttmann and Gille (1931) as closing the debate with the following statement: 'Alite, the chief constituent of high-lime Portland cement is neither (a) a lime-enriched dicalcium silicate (Dyckerhioff) nor (b) a solid solution of a lime-rich aluminate or Janeckite and 3Ca0.Si02 (Kuhl), nor (c) a solid solution chiefly of 3Ca0. Si02 and 3Ca0. A1203 (Guttmann and Gille), nor (d) a solid solution of Janeckite and 2CaO. Si02 (Janecke), nor (e) essentially 2Ca0. Si02 (Nacken) but Alite is tricalcium silicate. Thus, after fifty years, the question "What is Alite? " has been answered'. BY 1939, however, evidence (summarised in the next section) already existed showing that C38* could take up other constituents in solid solution, and some of the evidence indicated that this was accompanied by a change in structure.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available