Model Code 2010 creep and shrinkage models extension to recycled aggregate concrete

Abstract

Recycled aggregate concrete (RAC) produced with recycled concrete aggregate (RCA) is one of the most promising ways of eliminating concrete waste and saving natural resources. However, shrinkage and creep behaviour of RAC, important for serviceability design of reinforced and prestressed concrete structures, are still insufficiently studied and guidelines for RAC serviceability design are still not incorporated into design codes and standards. This study aims to systematize the knowledge gained on RAC shrinkage and creep behaviour thus far and to offer analytic expressions for predicting RAC shrinkage strain and creep coefficient. For this purpose, databases of previously published results on RAC shrinkage and creep were compiled and the results on RAC were analysed relative to companion natural aggregate concrete (NAC). The results showed a systematically higher shrinkage and creep of RAC relative to NAC. Finally, analytic expressions for correction coefficients, dependent on RAC compressive strength and RCA replacement ratio, were formulated for predicting RAC shrinkage strain and creep coefficient using the fib Model Code 2010.