Grain preparation and stabilization method using solidified cement made from sewage sludge incineration ash

摘要

PROBLEM TO BE SOLVED: To simply recycle burned ash of sewage sludge without a specific treatment by adjusting the carbon content of burned ash of sewage sludge to a specific value or smaller than it, mixing the burned ash with cement in a specific ratio, adding water to the mixture, solidifying and making a uniaxial compressive strength in a specific range. SOLUTION: The carbon content of burned ash of sewage sludge is adjusted to =3 wt.%. The burned ash of sewage sludge is mixed with cement in the weight ratio of 1:1 to 1:3 and a proper amount of water and solidified to give a cement solidified material having 100-200 kgf/cm2 uniaxial compressive strength (28 day material age). When the cement solidified material is ground to give a granular aggregate and the granular aggregate is mixed with Fe lime and natural soil, the granular aggregate is embedded in a matrix of Fe lime treated soil and a hydrate by a Fe lime-based stabilizer is formed on a contact face between the surface of the granular aggregate and the matrix. Consequently the strength of a stably treated roadbed is improved by the increase of bond strength and frictional resistance on the contact face.