Correlating Laboratory and Field Tests of Creep in High-Performance Concrete.

This article outlines experimental laboratory and field studies on creep of young or mature High Performance Concrete, HPC, carried out between 1991 and 1999. For this purpose about 400 cylinders made out of 8 mix compositions of HPC were studied in the laboratory. Half the number of HPC was sealed; half of the studies were carried out on air-cured HPC. Parallel tests on strength, internal relative humidity, RH, and hydration were carried out on about 900 cubes that were made of HPC from the same batch as the cylinders were. Fragments from the strength tests were used to observe RH. Shrinkage was studied parallel to creep. The results and analyses of the laboratory studies show large influence of the maturity and of the mix composition of the HPC on the measured creep. The creep coefficient of HPC is smaller than in normal concrete. In contrast, shrinkage of HPC is somewhat larger than in normal concrete. The results obtained in the laboratory were correlated to field tests on 27 beams. The results in the field coincided well with the results in the laboratory studies.