The effects of sludge ashes and nano-material on the volumetric variation of mortar

• Main Authors: Chin-Yan Li, 李錦彥
• Other Authors: Deng-fong Lin
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/35845263818870968787

碩士 === 義守大學 === 土木與生態工程學系碩士班 === 95 === In order to further investigate the effects of cement replaced by sludge ash on the paste, three different kinds of sludge ash and nano-SiO2 are used to make paste specimens. Moreover, the influences of different materials on the volume change of paste specimens are studied. Test results show that, when specimens were cured in the water, small amount of volume expansion and weight increase are noticed, especially for those specimens with oil sludge ash replacement. However, when observed from SEM. TEM, XRD, and NMR for those specimens cured in the saturated sulfate solution, more ettringite is produced resulting from the reaction between sulphric ion and hydration gel. As a result, the volume expansion rate of paste is increasing. Furthermore, results obtained from TGA-DTA indicate that the hydration product decrease with the increasing amount of cement replaced by sludge ash. This leads to a less weight loss in paste specimens. As for the nano-SiO2 additive, it can improve the growth of hydration products and effectively fill up pores inside the specimens. But, the nano-SiO2 would increase the expansion of paste specimens. Furthermore, the heat expansion rate increases with the increase of alkali content in the materials applied to specimens. Again, the oil sludge has the strongest effects among the three kinds of sludge tested.