Title: Mix Designs and Strength Data for Concrete Platforms in the North Sea

Author(s): A. K. Haug and M. Sandvik

Publication: Symposium Paper

Volume: 109

Issue:

Appears on pages(s): 495-524

Keywords: admixtures; air entrainment; compressive strength; permeability; fine aggregates; heat of hydration; high-strength concretes; workability; lightweight aggregate concretes; mix proportioning; offshore structures; setting (hardening); slipform construction;

DOI: 10.14359/2037

Date: 8/1/1988

Abstract:
To meet the development in structural design and construction methods, a continuous effort has been made to advance the concrete mix design process. Paper gives a survey of the research work in this process. The mix design has to take care of several contradictory requirements, such as high strength and low permeability on one side and moderate heat development and extraordinary workability on the other. From 1972 to 1986, the concrete grade has been increased from C45 to C70 while the workability (slump) has been increased from 120 to 240 mm mainly due to extreme dense reinforcement (above 1000 kg/m3 in local areas). The chemical composition of the cement is aimed at an optimized 28 day compressive strength with moderate heat development. The fine aggregates are produced through a hydraulic process to obtain the desired particle distribution. Minor changes in the finer part of the grading have resulted in remarkable improvements in the workability and pumpability by stabilizing the paste-aggregate matrix. The practical use of very high strength normal density concrete (C80-C100) and high-strength concrete with lightweight aggregates are new challenges for the concrete mix design so as to satisfy new advancements in construction methods.