Utilization of mass stabilized surplus mud and clay as fill and embankment construction material in urban building

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Researchers

Research units

  • City of Helsinki
  • Ramboll Finland Oy

Abstract

Marine sediments in the coastal areas are often contaminated as a consequence of industrial and port activities, as well as the influence of cities located there. Construction activities and reclamation of shoreline require dredging and management of contaminated sediments since the level of contamination inhibit dumping of dredged sediments into the sea. Most of these soft dredged and excavated sediments are regarded as too soft and poor quality for earth construction purposes. Mass stabilization technology has been applied to improve the technical and environmental properties of the dredged sediment in order to utilize it as earth construction material. At the treatment sites the dredged or excavated sediments are disposed in basins, mixed with binders by stabilization and transported to utilization sites or left to the basins for the foundation of harbour or port area.
The technical and environmental properties of stabilized dredged and excavated soft sediments and soils have been studied thoroughly in the laboratory scale and in situ in different construction phases - in the basin before and after stabilization and in the structure after transport and construction activities. By mixing binder with mud or clay, the soil will increase its strength and modulus. The studied properties of stabilized soils are e.g. compression strength, modulus, settling properties, hydraulic conductivity, leaching of contaminants, etc. The workability, including the vibration resistance during transportation to the utilization site, has been also studied.
The high price and carbon footprint of cement binder have encouraged the use of alternative binders. Other used binder materials include fly ash and end product of desulphurization from combustion of coal and oil shale. The leaching test results show that heavy metal leaching is very low with all binder materials tested. During the mass stabilization application process, it was observed that the great water content has a considerable impact on the amount of cement required as binding agent. It has been noticed that it is possible to obtain higher
strength and better homogeneity by mixing fly ash (and FGD) to low amount of cement (or lime) or to use oil shale ash alone as a binder.

Details

Original languageEnglish
Title of host publicationProceedings of 10th International Conference on the Environmental and Technical Implications of Construction with Alternative Materials
EditorsPentti Lahtinen, Ville Raasakka
Publication statusPublished - 6 Jun 2018
MoE publication typeA4 Article in a conference publication
EventInternational Conference on the Environmental and Technical Implications of Construction with Alternative Materials - Tampere, Finland
Duration: 6 Jun 20188 Jun 2018
Conference number: 10

Publication series

NameRIL / Suomen rakennusinsinöörien liitto
PublisherSuomen rakennusinsinöörien liitto
ISSN (Print)0356-9403

Conference

ConferenceInternational Conference on the Environmental and Technical Implications of Construction with Alternative Materials
Abbreviated titleWASCON
CountryFinland
CityTampere
Period06/06/201808/06/2018

    Research areas

  • mass stabilization, Deep mixing, Dredged sediment, Laboratory test, Leaching test, Quality assurance sounding

ID: 27185073