Azerêdo, Aline F. N. de

Lime-Metakaolin Mortars Produced From Kaolin Wastes Hardened and Microstructural Properties

Abstract eng:
Lime-pozzolan mortars are often used for the restoration of historical buildings. Several studies have been developed in regards to the use of waste in construction materials. In Brazil the kaolin industry has generated a lot of waste. Studies have been carried out on the use of kaolin waste as a replacement material for Portland cement concretes and mortars; and also for hydraulic mortars. In this work kaolin waste (KW) was studied as a pozzolan (metakaolin-MK). This waste is in the form of large particles similar to river sand, because of this it was also investigated as a potential aggregate in lime-pozzolan mortars. Mortars, with a ratio by weight of 1:3 (binder : aggregate) where the binder was made of a 50/50 mix of lime-MK and four different kaolin wastes as an alternative to river sand, were studied under two curing conditions (dry and moist). Hardened properties of these mortars like compressive and tensile strength, mass loss variation and capillarity were evaluated up to 180 days of curing. Microstructural characteristics were assessed using thermal analysis (TG/DTG), x-rays diffraction (XRD) and scanning electron microscopy (SEM). Mortars under moist curing conditions presented higher strengths (about 12 MPa) than those created in dry curing conditions. The microstructural analysis showed that the major hydrated phases found were stratlingite (C2ASH8) and monocarboaluminate ( A ̅ ) for mortars hardened in moist curing conditions and for those in dry conditions it was found that monocarboaluminate and calcium carbonate were the major phases. The mortars and pastes containing KW as a pozzolan and aggregate have presented a similar performance to mortars using commercial kaolin and river sand when comparing the results to others works. The results show that this material could be a good material to be used in lime mortars. Key Words: Kaolin, waste, mortars, lime.

Contributors:

Carneiro, Arnaldo M. P.

Publisher:

Glasgow : University of the West of Scotland, 2013

Conference Title:

Proceedings of the 3rd Historic Mortars Conference HMC13

Conference Title:

3rd Historic Mortars Conference

Conference Venue:

Glasgow, Scotland (UK)

Conference Dates:

2013-09-11 / 2013-09-14