• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.33 no.4
• /
• pp.1463-1469
• /
• 2013

Portland cement used as binding material in combination of ferrous iron for reductive dechlorination of chlorinated organics is already widely studied topic by several researchers. However there is no clear evidence about the component solely responsible in cement for trichloroethylene (TCE) dechlorination. Many researchers suspect that the ettringite, monosulfate phases associated with hydration of cement are responsible active agents for TCE dechlorination. This study deals with synthesizing different pure crystalline minerals like ettringite and monosulfate phases of cement hydration and check individual phase's TCE dechlorinating capacity in combination with ferrous iron. The results indicated that the synthesized minerals showed no reduction capacity for TCE. The findings in the present study is significant as it shows that ettringite and monosulfate phases which were suspected minerals by previous researchers for TCE dechlorination are not reactive. Hence it is suspected that some other mineral or mineral form in cement phase could be responsible for TCE degradation.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.22 no.2
• /
• pp.124-132
• /
• 2018

This research presents the results of an investigation on the characteristic of multi-component blended high fluidity mortars. The binder was blended ordinary Portland cement(OPC), ground granulated blast furnace slag(GGBFS), calcium sulfoaluminate(CSA) and ultra rapid setting cement(URSC). The GGBFS was replaced by OPC from 30%(P7 series), 50%(P5 series) and 70%(P3 series), CSA and URSC was 10% or 20% mass. The superplasticizer of polycarboxylate type were used. A constant water-to-binder ratio(w/b)=0.35 was used for all mixtures. Test were conducted for mini slump, setting time, V-funnel, compressive strength and drying shrinkage. According to the experimental results, the contents of superplasticizer, V-funnel and compressive strength increases with an increase in CSA or URSC contents for all mixtures. Moreover, the setting time and drying shrinkage ratio decrease with and increase in CSA or URSC. CSA decreased dry shrinkage but URSC had less effect. However, the mixed binders of CSA and URSC had a large effect of reducing drying shrinkage by complementary effect. This is effective for improving the initial strength of URSC, and CSA is effective for the expansion and improvement of long-term strength.