Title: Rate Constant Functions for Strength Development of Concrete

Author(s): Rajesh C. Tank and Nicholas J. Carino

Publication: Materials Journal

Volume: 88

Issue: 1

Appears on pages(s): 74-83

Keywords: concretes; construction; equivalent age; maturity; models; mortars (material); rate constant; strength; temperature; Material Research

DOI: 10.14359/2403

Date: 1/1/1991

Abstract:
The rate constant for strength development of a particular concrete mixture is the initial slope of the relative strength-versus-age curve at constant temperature curing. The form of the rate constant-versus-temperature function is needed to describe the combined effects of time and temperature on strength development. This study investigates the relationship between the rate constant and curing temperature. Based on strength-gain data for concrete and mortar specimens made with Type I cement and cured at 10, 23, and 40 C (50, 73, and 104 F), the following conclusions are drawn: 1) strength gain can be represented by a three-parameter hyperbolic function; 2) the rate constant is a nonlinear function of curing temperature, and a simple exponential function describes this relationship; 3) tests of appropriate mortar specimens provide the information needed to predict relative strength development of the corresponding concrete; and 4) the proposed rate constant model accurately describes the development of relative strength as a function of the equivalent age.