| Summary: | 碩士 === 國立中興大學 === 土木工程學系 === 93 === The purpose of this study is utilizing the coal bottom ashes (CBA) to produce lightweight aggregates (LWA). According to the physical properties, chemical components and mineral constituents of the CBA, a series of attempts are made to sintering the CBA with various sintering temperature (1100－1250 ℃) and time (5~10 min). From the results of attempts on sintering and essential properties of CBA , the burning conditions and mix proportions are preliminarily determined to produce LWA. Further, based on the physical properties of LWA (particle density, 24 hrs water absorption, bloating index, and pore content etc.), the sintering conditions and mix proportions appropriate for producing LWA are selected. Finally, perform the mass production of LWA and evaluate the corresponding mechanical properties of LWA. (loose weight, strength of particles and chloride ion content etc.)
The experimental results show that the CBA should be ground for granulation and production and the content of the fluxing should not be too high (≦26%) for manufacturing the agglomerate lightweight aggregate. The fluxing is considered as a kind of adjuvant admixture, which can reduce the melting point and amend the expansion of the raw material. Besides, the content of the carbon in CBA will greatly affect the properties of aggregates. After sintering, the carbon can provide pores and gases for aggregates during the process of expansion, and reduce the weight of aggregates. Draw from the above mentioned, lightweight aggregates are able to be made form CBA successfully with the values lying between 1037－1901 kg/m3 for the particle density, 0.1%－18.3% for the 24 hrs water absorption, and 3.5－23.5MPa for the bulk strength, and which can achieve the requirements of the general applications of lightweight aggregates.
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