A NEW APPROACH TOWARDS DURABILITY DESIGN OF CONCRETE STRUCTURES

Abstract

A method of assessing durable life of concrete structures is presented. The durable life is related to the Durability Design Index (DDI). The DDI is obtained from the product of various durability factors which are empirically assigned to the durability requirements of the most commonly used codes of practice like ACI, BS and JCI The factors have been grouped into four categories; the durability loading, compliance to standards, protective provisions and degrees of certainty. The durability loading factors are made dependant upon aggressiveness of environment, magnitudes of displacements and deformations, reinforcement detailing and concrete cover factors. The compliance to standards factors are based upon concrete strength, quality of concrete composition, quality of reinforcement detailing and construction methodology. The protective provision factors are classified as casting stage, finishing stage and service stage protective provision factors. The degree of certainty factors have been related to the level of skill of the design and construction teams. Three case studies have been presented and the results of these case studies agreed very closely to the prediction of the proposed method.