| dc.description.abstract | Paper Sludge Fly Ash (PSFA) is produced by the Circulating Fluidized Bed, by the boiler, spray cooling tower, bag dust collection, in order to understand the expansive problem of PSFA reutilization and the feasibility of utilization in controlled low-strength material (CLSM), this study is divided into three stages for discussion. The first stage: analysis of The basic properties and expansion problems of PSFA; the second stage: to explore the engineering properties of PSFA using volume instead of fine aggregate to make mortar; the third stage: to explore the feasibility of PSFA using volume to replace fine aggregate to make CLSM.
The first stage is to analyze the basic properties and expansion problems of PSFA. The test results show that the physical and chemical properties of PSFA sampled at different times to take are very different. The XRF and XRD analysis of PSFA sampled which was taken by ourself shows a higher CaO content, and The CaO content of PSFA provided by the manufacturer is less than 5%, and the compound shown by XRD is close to the coal-fired fly ash of the power plant. In terms of expansion, the expansion rate of PSFA decreases with the increase in the number of days for stabilization by adding water, which shows that time is required to stabilize PSFA by adding water to effectively reduce its expansion. Therefore, PSFA must be stabilized by adding water for at least 10 before reuse and recommended to use an autoclave test to confirm whether the PSFA has stabilized.
In the second stage, to research the engineering properties of mortar are made of PSFA by volume instead of fine aggregate. The test results showed that under the control of the water-cement ratio, the mortar with a replacement amount of 25% has better hard and dense properties; Substituting PSFA for a proper amount of fine aggregate can effectively improve the durability of the test body. However, in the volume stability test results, the replacement of part of the number of fine particles by PSFA will increase the shrinkage of the specimen. When the replacement amount reaches 35% Has the largest shrinkage.
The third stage is to explore the feasibility of using PSFA to replace fine aggregate to make CLSM. After the preliminary test, according to the results, a design that reduces costs and improves the economy. Design the cement 150, 130, and 110 kg/m3. When the amount of PSFA replaced by the fine aggregate is 15~35%, it can be made into CLSM with fresh mix properties and 28-day compressive strength in compliance with the specification; but when the replacement amount is 50~100%, C150 and C130 series of CLSM fresh mix properties can meet the specifications, but the 28-day compressive strength will exceed the specification requirements of 20~90 kg/cm2. Therefore, when the PSFA replacement amount is 50~100%, it is recommended to reduce the amount of cement It is 110 kg/m3. | en_US |