FROM DESIGN OF STRUCTURES TO DESIGN OF MATERIALS

During the last few years our conceptual thinking about concrete has changed. It is more and more understood that one can influence the properties of concrete quite considerably by minor changes in the concrete composition. Adding silica fume to concrete meant already the step toward what was called high strength concrete, some years ago. This qualification is subject of inflation, since it was detected that the particle packing can be improved by combining particle fractions of different orders of magnitude, whereas modern superplasticizers guarantee that the workability is not only maintained but even improved. Furthermore self-compacting concrete has become the most promising improvement of the labor conditions since a long time. Also fiber concrete has become more than only a promising material, which it has been for many years. Self-compacting fiber concrete may as well be an important contribution to high quality construction. Not only its workability is excellent, also the mechanical properties are improved and the scatter is reduced. It is felt that a new challenge is facing us: developing concretes to satisfy performance requirements instead of strength requirements. So gradually high strength concrete has turned into high performance concrete and now to defined performance concrete.

• INTRODUCTION

• CONCRETE AS A CONVENTIONAL BUILDING MATERIAL

• CONCRETE WITH ULTRA HIGH STRENGTH

• SELF-COMPACTING FIBER REINFORCED CONCRETE

• SPECIAL EXAMPLES OF TAILOR MADE CONCRETE

• GREEN CONCRETE

• CONCLUSIONS

• REFERENCES