• Journal of Korean Society of Environmental Engineers
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• v.37 no.7
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• pp.412-417
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• 2015

This study investigated to recycle geobond and ash produced in thesewage sludge incinerator using reduction/stabilization. Nonsintering process was performed by binding cement (High Early Strength Portland cement, Micro cement), geobond and sand mixed with sewage sludge ash (SSA). Chemical ingradients of the sewage sludge ash was mainly composed of $SiO_2$, $Al_2O_3$, $Fe_2O_3$, CaO and others, which were similar to those of the each binders consisting High Early Strength Portland cement, Micro cement and geobond. Results showed that unconfined the long term compressive strength could be obtained components of sewage sludge ash. It exceeded more than double score 64.6 MPa of the Korean standard ($22.54MPa=229.7kg/cm^2$). Microstructure of solidified block for the different admixture was related to the compressive strength according to SEM analysis. Optimum mixing range of the sewage sludge ash to each binders were found to be 10~40% which can widly safely regulate the confined a long term compressive strength. The best binder of long term compressive strengh was revealed Geobond more than High Early Strength Portland cement and Micro cement. This study revealed the sewage sludge ash can be partial replacement of the inorganic binder & application block for recycling.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2007.04a
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• pp.71-74
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• 2007

This study investigates the fundamental properties of high strength concrete made with various blame values of cement, manufactured by the particle screening method in a pulverizing process. Test showed that concrete using lower blame of cement, such as large particle (L) and both ordinary and large particle (OL), increased the fluidity of fresh concrete. As tine progressive, it was noticeable that the specimens using ordinary cement (OPC) gradually decreased the fluidity, but the other specimens showed the sudden decline until 30 minutes, which is followed by a gradual decrease after 60 minutes. For the setting time, higher blaine of cement accelerated the initial and final setting time, especially concrete using minute size of cement (M) was 10 hours faster than OPC. Compressive strength of L exhibited similar value at 1 days as to that of strength in OPC at 3 days. Importantly, the specimens using M also revealed the similar strength value, regardless of curing temperature between $-5^{\circ}C$ and $20^{\circ}C$, which means that using this minute particle of cement in concrete can secure the strength development even in the lower temperature circumstance. Therefore it is clear that using OPC+M simultaneously at cold weather concreting can resist the early frost and develop the early strength of concrete.