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Compressive strength prediction of concrete is essential in cold weather concreting. Maturity method and strength prediction method using logistic curve have been used for cold weather concreting in Japan. This method is limited within the range from water to cement ratio 45% to 65%. In this paper, we propose a strength prediction method for enhancing the range of water to cement ratio. The experimental data in the past was used and analyzed. As a result, the approximation by Gompertz curve showed high accuracy in the strength prediction of the concrete within the wide range of water-cement ratio. We propose the new strength prediction method for applying Gompertz curve.

We investigated hydration and strength developrnent of cementitious materials cured under freezing or drying condi ・ tion experimentall γ The test results show that hydration and stren 匹 h development depend onboth tenΨ erature and chemical potential ofwater ． Theoretical study makes it clear that e飩 ct oftemperature fblows the Arrhenius equation and the activation energy in the equation is proportion 湿 to the decrease of chemical potentia1 ． Consequently the equivalent maturity method that describes the rate ofhydration under dryin 匿 a皿 d freezing condi ・ tion was proposed ． ffeywords ；hydration rate ， strength development ， hydratien ratio ， chemical potential， maturity method