Abstract: A method of cracking a heavy hydrocarbon oil containing a residual fraction with a boiling point of 538.degree. C. or higher, including contacting the heavy hydrocarbon oil with a fluidized bed of a particulate composite catalyst which includes an amorphous refractory inorganic oxide and a crystalline aluminosilicate dispersed in the oxide and which has a surface area distribution such that the surface area of pores having pore diameters in the range of from three times to six times the average molucular size of the residual fraction is at least 60% of the surface area of pores having pore diameters in the range of 15-150 .ANG..

Abstract: A high water content soft soil, for example from the sea or river bed, may be improved in strength by incorporating thereinto an additive composed of ingredient A including a mixture of 5-45% by weight of gypsum and 95-55% by weight of a water-granulated iron blast furnace slag having an particle size within the range of 100-1 .mu.m and ingredient B including a Portland cement. The ratio by weight of ingredient A to ingredient B is within the range of 75/25-55/45. Ingredient A is incorporated into the soft soil before incorporation of ingredient B.