CHARACTERISTICS OF MATERIALS TO TAKE INTO ACCOUNT IN CALCULATIONS

CARACTERES DES MATERIAUX A PRENDRE EN COMPTE DANS LES CALCULS

TO DEFINE ACCURATELY THE VALUE OF THE MATERIALS CHARACTERISTICS TO TAKE INTO ACCOUNT IN CALCULATIONS, IN EXISTING OR FUTURE REGULATIONS. ADVICE AND PROPOSALS WERE PUT FORWARD REGARDING THE DRAFT SPECIFICATION MODEL OF THE EUROPEAN COMMITTEE OF CONCRETE (CEB) AND THAT OF THE NEW REGULATION GOVERNING THE DESIGN OF PRESTRESSED CONCRETE STRUCTURES (VOLUME 52) ON THE FOLLOWING: TIME-RELATED RELATIONS BETWEEN COMPARATIVE STRENGTH, TENSILE STRENGTH AND MODULUS; SHRINKAGE AND CREEP OF CONCRETE, STEEL RELAXATION; LOSS OF PRESTRESSING IN THE CASE OF PRETENSIONING. IN 1979, PROPOSALS AND JUSTIFICATIONS WILL DEAL WITH: THERMAL AND HYDRAULIC SHRINKAGE DURING THERMAL TREATMENT; INFLUENCE OF THE RATE OF TEMPERATURE RISE ON THE LONG-TERM CHARACTERISTICS OF THERMALLY TREATED CONCRETE; EVOLUTION IN THE BULK DENSITY OF LIGHTWEIGHT CONCRETE ACCORDING TO CURING CONDITIONS.