Optimising short-term and long-term properties of high-volume fly ash (HVFA) concrete

Ling, X 2015, Optimising short-term and long-term properties of high-volume fly ash (HVFA) concrete, Doctor of Philosophy (PhD), Civil, Environmental and Chemical Engineering, RMIT University.


Document type: Thesis
Collection: Theses

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Title Optimising short-term and long-term properties of high-volume fly ash (HVFA) concrete
Author(s) Ling, X
Year 2015
Abstract The demand for concrete as a construction material has increased due to its durability and low cost, the growth of the world’s population and the rapid development of the construction industry. The increased usage of concrete consequently increases the use of Portland cement and leads to high emissions and energy consumption. The research presented here aimed to replace over 60% of cement with fly ash in the production of concrete without causing any adverse effects on the properties of concrete.

After a comprehensive literature review, potential methods of improving properties of high-volume fly ash (HVFA) concrete were identified as: provision of additional lime for the pozzolanic reaction, reducing the particle size of fly ash to improve reactivity and increasing the temperature of mixing water to increase the rate of the reaction. A comprehensive experimental program demonstrated that the use of limewater as mixing water and using ultra-fine fly ash will increase the performance of HVFA concrete. An optimised mix design was developed for a HVFA concrete with 65% cement replaced by fly ash without any adverse effects on concrete strength compared to Portland cement concrete with the same binder proportion. It was noted that increasing the temperature of the mixing water does not improve the properties of the HVFA concrete.

Short-term and long-term properties of the new concrete were examined via a comprehensive experimental program conducted on compressive strength, elastic modulus, flexural strength, tensile strength, drying shrinkage and creep. Apart from drying shrinkage, all the other properties of the new concrete were similar or superior to those of an equivalent Portland cement concrete. It was established that the high drying shrinkage observed in the new concrete can be controlled by early age curing.
Degree Doctor of Philosophy (PhD)
Institution RMIT University
School, Department or Centre Civil, Environmental and Chemical Engineering
Subjects Construction Materials
Keyword(s) High-volume fly ash concrete
Concrete mix design
Creep and shrinkage
Short-term properties of concrete
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Created: Wed, 06 Apr 2016, 09:16:09 EST by Keely Chapman
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