RELIABILITY EVALUATION OF IN-SITU STRENGTH OF REINFORCED CONCRETE MEMBERS

RELIABILITY EVALUATION OF IN-SITU STRENGTH OF REINFORCED CONCRETE MEMBERS

Abstract:

A description is presented for extending reliability analysis concepts or probabilistic approach to the formation of design equations and compliances on sites to the equations. The design equations for concrete structural elements were reviewed. The test gave very reasonable prediction of how reliably the design equations are and the compliance of workmanship to the design equations requirements. The First Order Reliability Method (FORM) was reviewed as a basis for the study in which the inherent uncertainties in material and geometric properties together with loading conditions were explicitly considered. A FORTRAN 77 computer program was followed to compute the reliability levels implicit in the design equations in respect of field tested values of structural elements like slabs, beams and short columns. The statistical values for the design variables were based on information obtained from sites. The results obtained showed that with all the basic variables assuming normal distribution, the implicit reliability levels, (3, range from 4.96541 to 7.2113 for short columns, the interpretation of this high value of reliability level is due to the fact that on all sites there are good quality control and good workmanship, which results in small coefficient of variation. The variations of reliability level with span, varying compressive strength, yield strength were compared.

RELIABILITY EVALUATION OF IN-SITU STRENGTH OF REINFORCED CONCRETE MEMBERS