Special Solidificants have often been used in recent years for treatment of Hedoro (bottom sediment mud) and soft soil. However, the conditions for application and the effects of such special solidificants are not yet thoroughly understood. Comparison tests of 14 varieties of cement-type solidificants were therefore performed.
(1) The solidificants were found to contain CaO, SiO2, Al2O3 and SO3, and were divided into six groups according to the amounts of these components contained.
(2) A solidificant having a large content of SO3 (11∼13%) produced the highest strength. On the other hand, ordinary portland cement and solidificants of similar composition produced low strengths.
(3) It was observed by means of an X-ray diffractometer and a scanning electron microscope that the formation of ettringite in solidified soil contributed greatly to strength gain.