Title: Microporosity, Creep, and Shrinkage of High-Strength Concretes

Author(s): V. Penttala and T. Rautanen

Publication: Symposium Paper

Volume: 121

Issue:

Appears on pages(s): 409-432

Keywords: blast furnace slag; creep properties; high-strength concretes; porosity; shrinkage; silica fume; tests; Materials Research

DOI: 10.14359/2555

Date: 11/1/1990

Abstract:
This investigation reports on three high-strength concretes produced by low-heat portland cement with silica, blast furnace slag cement, and rapid-hardening portland cement, and a normal strength control concrete produced by rapid-hardening portland cement. The weight losses of creep and shrinkage cylinders are compared to corresponding deformation values at 1 year. The porosities of creep and shrinkage concrete specimens were determined by mercury porosimeters at the age of 7 days when the tests started and, thereafter, at the ages of 14, 35, and 372 days. The microporosity of binder paste specimens was determined by nitrogen adsorption at the ages of 14 and 35 days. The creep and shrinkage values of the high-strength concretes are compared to the values obtained by CEB formulas. It is concluded that the initial creep and shrinkage rate of high and normal strength concretes is governed by the evaporable water amount lost to the external environment. The average pore radii of the test concretes emptied from water during the creep and shrinkage tests were calculated.