New developments with respect to concrete

The present paper addresses several topics in regard to the sustainable design and use of concrete based on the binders cement, quicklime and/or gypsum. First, major features concerning the sustainable aspects of the material concrete are summarized. Then the major constituent, from an environmental point of view, cement is discussed in detail, particularly the hydration and application of slag cement. The intelligent combining of mineral oxides, which are found in clinker, slag, fly ashes etc., is designated as mineral oxide engineering. It results among others in environmentally friendly binders, recipes for soil stabilization (new building products), and impermeable/durable concretes. Subsequently, the mix design of concrete is treated, whereby distinction is made between self-compacting concrete and earthmoist concrete. By combining the particle sizes of all components, so including the powders (cement, fillers), optimum mixes in regard to workability/compactability and hardened state properties are obtained. This so-called particle size engineering results in concretes that meet all technical requirements, but that also make optimum use of the cement it is containing. This paper concludes with summarizing the opportunities and challenges involved with the introduction of both approaches, viz. mineral oxide engineering and particle size engineering, in the construction industry.