Shrinkage test of concrete: Methodology and variation of strain

Abstract

Abstract Evaluation of shrinkage strain in long concrete structures such as prestressed concrete box girder bridges is very important for the design of such structures. A wrong evaluation may contribute to loss of prestressing force, excessive deflections, cambers and cracking of the structure. It may also affect the durability and serviceability of the structure. The value of shrinkage strain is required during design, far before the construction process. However, realistic evaluation is still a difficult problem because shrinkage strain is influenced by the concrete composition and environmental factors such as humidity and temperature. Therefore, to gain the best evaluation, an experimental program was conducted to measure the shrinkage strain of concrete versus concrete age. Several concrete specimens were collected during pouring of several box girder segments of Tauranga Harbour Link, New Zealand. Variation of shrinkage strain versus concrete age for almost two years of data collection was plotted.