ABSTRACT
Not long ago, the terms ‘high performance composites’ and ‘advanced com posites’ were applied only to such composite materials as carbon fi bre reinforced plastics and metal matrix composites, used in the con struction of aircraft, rockets and satellites. These terms are now used for concrete-like materials and have similar meaning: they are materials of improved selected properties, designed and produced for special applications. The concept of high performance is expressed by the following technical terms:
better consistency of the fresh mix, i.e. its workability, mobility, com-• pactability, pumpability and finishability, to ensure good result of execution without much energy expense or much effort from workers, often resulting in excessive scatter of local properties; good behaviour of materials in their hardened state, i.e. strength and • deformations fulfi lling standard requirements with a suffi cient safety margin for certain unpredictable situations, and without weak regions; relatively high strength, also at early ages, i.e. after one, three or seven • days; acceptable behaviour in the long-term; therefore improved durability • adequate to requirements during the forecast life of the structure, low maintenance costs and relative facility of repair works; good aspect of the structure during service life, i.e. without visible cracks • and voids, excessive defl ections, spallings etc.
