Estimation, based on the maturity function, of the strength of early age concrete cured at elevated temperature

In mass production of concrete precast units, it is important to optimise technology which would ensure high early age compressive strength of concrete, and also follow the principles of sustainable manufacturing and reduce costs. The paper presents the analysis of results obtained for three series of concretes made from CEM I42.5R cement, at the water-cement ratios of 0.34, 0.38, and 0.42, cured at different temperatures, namely 20, 40 and 60°C, where heating was performed in 16-hour cycle. The analysis aimed at determining functional properties which allow the estimation of concrete compressive strength depending on the temperature history. The Carino-Lew function was adopted to determine the relation between the curing time and temperature and the equivalent curing time te. The determined values of cement thermal sensitivity factor ranged 0.023÷0.040, which was related to the w/c ratio and the strength level. An exponential function was developed to express concrete compressive strength dependence on the equivalent curing time te. In the authors’ opinion, the function can contribute to the optimisation of the production process of concrete precast units by means of designing the temperature profile, depending on the concrete mix formulation and the assumed level of concrete structural strength.

---

Wyniki przedstawione w publikacji zostały uzyskane w trakcie badań sfinansowanych w ramach Projektu „Perspektywy RSI Świętokrzyskie – IV etap” nr: WND – POKL.08.02.02-26-001/12 – Program Operacyjny Kapitał Ludzki, Priorytet VIII, Działanie 8.2 Transfer wiedzy, Poddziałanie 8.2.2 Regionalne Strategie Innowacji.