Title: Mass Concrete Properties at High Temperatures

Author(s): K. W. Nasser and R. P. Lohtia

Publication: Journal Proceedings

Volume: 68

Issue: 3

Appears on pages(s): 180-186

Keywords: age;compressive strength;concretes;curing;elastic properties;high early strength cements;high temperature tests;mass concrete;modulus of elasticity; moisture content;nuclear reactors;pressure vessels;research.

DOI: 10.14359/11318

Date: 3/1/1971

Abstract:
Tests were performed on mass concrete cylinders for over 6 months at temperatures of 35 to 450 F. Two types of intial curing were used: some cylinders were exposed to the different temperatures at 1 day while others were heated from 14 days onward. The strength and elastic properties of the concrete were determined at several intervals during 6 months. Aminimum of three cylinders were tested at each condition and over 350 specimens were tested. The results show that strength and elasticity are independent of temperature from 35 to 200 F starting at about 28 days. However, at higher temperatures both properties are affected adversely and significantly. After 6 months of exposure to 450 F, the showed a loss in strength and elasticity of about 50 to 68 percent, respectively. The intial curing conditions did not influence the results significantly. Speculation as to the cause of deterioration under high temperatures is attributed to the change of the atobermorite gel into weak and crystalline phases of poor cementing qualitites.