Movement in a seven storey reinforced concrete frame

Abstract

The construction of a seven storey reinforced concrete (RC) frame at the Building Research Establishment's Large Building Test Facility in Cardington, (the European Concrete Building Project) provided an ideal opportunity to obtain long-term movement data for a number of different standard and innovative concrete mix designs and to assess the accuracy of existing design methods for predicting elasticity, shrinkage and creep. The investigation involved monitoring the strain of a number of columns of the RC frame and carrying out creep and shrinkage tests on small concrete specimens over a period of nine months. The columns were made from concrete having grade strengths from 37 to 85 MPa and contained mineral and chemical admixtures. The actual movements were then compared with movements predicted from the corresponding small concrete prism measured test data using established prediction methods. The results of the analysis indicated that the movements of the columns within the RC frame were predicted to within the range of 10–20%. In addition, elastic, creep and shrinkage movements of the small concrete prisms can be predicted satisfactorily by the CEB-FIP Model Code 90.