Economical and ecological optimization of binder system

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Journal Title
Journal ISSN
Volume Title
School of Engineering |
Date
2014
Major/Subject
Rakennusmateriaalitekniikka
Mcode
Rak-82
Degree programme
Language
en
Pages
104 s. + liitt. 56
Series
Abstract
The environmental preservation and sustainable design has become an important issue for all industries, including the cement industry. Cement industry contributes 5% of the CO2 emitted to the atmosphere every year. For the production of 1 Tonne of Portland cement, 1 Tonne of carbon dioxide is emitted to the atmosphere. The main purpose of this research was to optimize the utilisation of alternative to OPC cementious binders in the concrete production. Five different kinds of binders were studied, including three ordinary mixes: Portland Cement, Portland Cement + Fly Ash, Plus-Cement + Fly Ash and two alkali-activated (AA) mixes: Portland Cement + Fly Ash + Blast Furnace Slag and Blast Furnace Slag + Limestone filler. The study was done in two steps: Initial Laboratory Studies, where the binder mixes were optimized focusing on compressive strength and workability, and Final Laboratory Studies where chosen optimised earlier mixes were studied in more detail including also their ecology and economy. The results showed that heat treated samples reached higher early compressive strength in comparison with no heat treated specimens. Compressive strength in alkali-activated binders was higher due to the activation with water-glass. The temperature of normal OPC concretes reached up to 55°C. The AA concrete showed much lower temperatures, what is beneficial for thick and heavily restrained concrete elements (such as walls). In the economical study, the ordinary mixes showed similar costs, while the alkali activated mixes were more expensive. On the contrary, in the ecological analysis, the AA mixes showed much lower CO2 emissions.
Description
Supervisor
Cwirzen, Andrzej
Thesis advisor
Punkki, Jouni
Keywords
concrete, precast, alkali, fly ash, slag, limestone, plus-cement, water-glass
Other note
Citation