Overburden soil and marine dredging sludge utilization for production of new composites as highly efficient...

The main objectives of this study were to develop new composites only from industrial wastes: overburden soil (40-60 wt%), dredging sludge from marine port sediments (20-40%) and lime production waste as a binder (15-30%). The axial resistance strength of the developed materials, on the 365th day, was 18.9 MPa and the values of apparent density and dilatation coefficient ranged from 2.69 to 3.14 g/cm³ and from 0.14 to 1.56%, respectively. Water absorption values after 90 days of cure varied between 8.9 and 15.1% and water resistance coefficient reached 1.17. They can be used for the production of construction materials such as tiles, bricks, and blocks, as road base and airfield runways, dam cores, industrial and municipal waste dumps bases, building foundations. The studies of the developed material, by the methods of XRD, AAS, SEM, EDS, DTA - DTG, tomographic mapping of the chemical elements and isotopic composition (LAMMA), demonstrated the synthesis of new formations, mainly amorphous, with small inclusions of crystalline structures. Results of leaching and solubility tests by the AAS method showed the full ecological compatibility of the developed materials with the environmental standards of Brazil.