A NORDTEST method for verification of self-desiccation in concrete

Abstract

This article outlines a new NORDTEST method for verification of self-desiccation in concrete. The method involves measurements of the internal relative humidity (RH) on pieces of concrete at age 1 month. The measured RH is then compared with the requirements according to the owner. The new NORDTEST method for self-desiccation permits requirements to be made of the self-desiccation of high-performance concrete (HPC) in accordance with present demands on strength. During the development of the test method, experimental studies were carried out on nine concretes with water/cement ratio (w/c) varying between 0.32 and 0.50. Half of the concretes contained 5% silica fume. The experiments showed a significant effect of cement type, silica fume, and w/c on the self-desiccation in concrete. The test method was also verified in the field, both when manufacturing the concrete and on site. The method was developed after cooperation between the Technical University of Denmark and Lund University. The experimental studies were performed at the Division of Building Materials, Lund Institute of Technology, Lund, Sweden in 1995–1999.