Technological Effects, Physical Characteristics and Reactivity in Cement
Collection editors:
Scrivener, Karen; Favier, Aurélie
Title of conference publication:
Calcined Clays for Sustainable Concrete
Subtitle of conference publication:
Proceedings of the 1st International Conference on Calcined Clays for Sustainable Concrete
Series title:
RILEM Bookseries
Series volume:
10
Organizer (entity):
Swiss Federal Institute of Technology Lausanne, EPFL
Conference title:
International Conference on Calcined Clays for Sustainable Concrete (1., 2015, Lausanne)
Venue:
Lausanne
Year of conference:
2015
Date of conference beginning:
23.06.2015
Date of conference ending:
25.06.2015
Place of publication:
Dordrecht
Publisher:
Springer
Year:
2015
Pages from - to:
43-50
Language:
Englisch
Abstract:
The investigation reveals chances for calcined clay comprising a mixture of different clay minerals as supplementary cementitious material. There is ample supply in southern Germany of the source material with its quartzous clay combined with a high content of mica and other clay minerals. Its content of kaolinite is less than 25 % by mass. The calcinations were done following two different procedures. On laboratory scale the raw clay was dried initially, crushed to a maximum particle size of less than 4 mm and subsequently calcined in small quantities of 50 g in a muffle furnace. On an industrial scale the raw clay was crushed coarse to a maximum particle size of 100 mm and subsequently fed in campaigns of 180 tons each into a tripartite rotary kiln normally used for the production of expanded clay. The resulting calcined clay particles had a maximum size up to 40 mm. Characteristic chemo-mineralogical properties and physical parameters (e.g. mineral composition and amorphous content, lime - retention, ion solubility in alkaline medium and BET - surface) of the calcined clays were measured. The comparison of the clays calcined in the laboratory and those calcined on industrial scale revealed a broader optimum temperature range for the latter accompanied by a partially reduced pozzolanic reactivity when used in combination with cement. «
The investigation reveals chances for calcined clay comprising a mixture of different clay minerals as supplementary cementitious material. There is ample supply in southern Germany of the source material with its quartzous clay combined with a high content of mica and other clay minerals. Its content of kaolinite is less than 25 % by mass. The calcinations were done following two different procedures. On laboratory scale the raw clay was dried initially, crushed to a maximum particle size of le... »