The extensive CBI project between 1995-98 in co-operation with Swedish National Road administration Construction and Maintenance is the basis describing the Swedish experience of self-compacting concrete, SCC, in civil engineering structures up to the summer of 1999. _x000D_ _x000D_ It's material development originates in mid-eighties Japan, to increase productivity, improve working conditions and especially so in difficult casting conditions. Today it is still characterised as a "special" concrete but on-going development may eventually change this to "conventional" concrete, as the working research experience of self-compacting concrete starts in Sweden only in 1993. _x000D_ _x000D_ SCC is not one concrete but a concrete material possessing certain characteristic properties in the fresh state, completely fills formwork and encloses reinforcement work, entirely under the influence of its own weight alone. Thus, while fulfilling all the normal work of conventional concrete it can be developed for all kinds of applications, including where concrete vibration is impossible. SCC, properties require strict tolerance in plant production and delivery, for variations in the fresh state cannot be compensated by compacting work. Some of the main variables influencing variation, e.g. aggregate moisture and grading are discussed. _x000D_ _x000D_ Handling experiences at construction sites are enlightening with many interesting casting techniques reported from Japan, where casting of completely closed formwork is monitored by sensors, an interesting technique for tunnel applications, etc. Swedish experience shows SCC behaving thixotropically so that a structural build up in fresh concrete occurs soon after placing, resulting in remarkably low form pressures. _x000D_ _x000D_ A CBI mix design model is presented showing that the mix is developed by considering the actual aggregate used at the plant. From this perspective, all plants have the potential of producing SCC, where the mix design model is based on calculating the minimum required paste volume (according to the local aggregate) enabling free flow through narrow obstacles. The paste design is achieved by rheological measurements of the fine mortar phase. The main mechanisms behind particle suspension rheology are discussed. Fresh properties, flowability, stability and blocking are verified using newly developed methods, with slump-flow and L-box as examples of new test methods. _x000D_ _x000D_ A general experience is that hardened SCC properties are superior to conventional concrete in that compressive strength often is 70 to 80 MPa and denseness expressed as chloride ion permeability normally equals to W/B ratios of approximately 0.35 (actual W/C ratio being 0.40). Explanations to these properties are discussed. _x000D_ _x000D_ Future research should be concentrated on plant production quality assurance and production systems where SCC properties are fully utilised. Reports show that total bridge building cost can be reduced by as much as 5 to 15 %.