| Summary: | 博士 === 國立臺灣科技大學 === 營建工程系 === 103 === Limestone which produces lime is available in large quantities in many parts of the world. Continuous formation through the deposit of shells and skeletons of land and marine animals and organisms ensures that it will always be available and is thus a sustainable material. On the other hand, fly ash and silica fume are ready-to-use industrial wastes produced respectively during the burning of coal and in the manufacture of silicon and its alloys. These materials are ideal for the production of cement for the construction industry. Lower burning temperatures of lime compared with Portland cement and the ability to blend with larger amounts of pozzolana reduce the consumption of energy and natural raw materials and the emission of CO2 during cement production, thereby making cement greener. However, low early strength has been a setback for the use of lime-pozzolana cement. This study attempts to produce lime-pozzolana paste of high strength and explores the effects of powder proportions, water-binder ratio, fineness of lime, curing conditions, and pre-soaking lime on the early strength of paste made from non-hydraulic lime, type F fly ash, and silica fume. Paste with 28-day strength of 35 MPa is obtained. The consumption of raw materials and energy and emission of CO2 are reduced by factors of 2.6, 2.7, and 2.5, respectively compared with Portland cement. However, tests show that at early ages, lime-pozzolana paste is porous and potentially less durable and prone to leaching. This setback can be mitigated by covering lime-pozzolana concrete with impervious coating after water curing.
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