Title: Behavior of High-Performance Concrete (HPC) under Ammonium Nitrate Solution and Sustained Load

Author(s): U. Schnieder and S.-W. Chen

Publication: Materials Journal

Volume: 96

Issue: 1

Appears on pages(s): 47-51

Keywords: corrosion; high-performance concrete; high-strength concrete; stress corrosion

DOI: 10.14359/427

Date: 1/1/1999

Abstract:
The behavior of high-performance concrete (HPC), immersed into solutions of 10 percent NH4NO3 (NH4 = 22,500 mg/l) and 1 percent NH4NO3 (NH4 = 2250 mg/l), under bending stresses with a load level of 30 percent of their failure strength, was studied. The strength and weight loss of the specimens were determined. The diffusion of the ammonium nitrate solution into the HPC was also measured. A life-time coefficient was proposed to describe the strength reduction of concrete under stress corrosion. For comparison, the behavior of the specimens immersed into Ca(OH)2 saturated water was studied The results indicate that the strength and weight of the HPC in the ammonium nitrate solution was proportionally reduced with the time of immersion. The rate of decrease in flexural strength was the same as that in compressive strength. A high initial strength led to a comparatively high resistance against stress corrosion. A higher concentration of the aggressive solution resulted in reduction of the strength and weight. The additional bending stresses significantly accelerated the rate of chemical attack, resulting in severe stress and corrosion effects.