High Temperature and Cracking: Equations to Avoid High-Heat Concrete Mixtures in Massive Bridge Footings

This study aims to provide engineers with a set of equations to evaluate temperature models for massive footings to avoid the use of high-heat mixtures that can induce excessive expansion. The temperatures of a concrete block and 41 massive footings were measured in the laboratory and construction sites. The equations for the peak core temperature ($T_{\mathrm{PC}}$), peak differential temperature ($T_D$), and form removal time ($t_{\mathrm{FR}}$) are proposed for the thermal resistance of $0.029\mathrm{W}/\mathrm{m}·\mathrm{K}$ for 12.7-mm-thick expanded polystyrene (EPS) and extruded polystyrene (XPS) boards or equivalent. Semiadiabatic temperature rise ($T_R$) curves from 1.1-m elements can be used to model footings up to 1.8 m thick. The gradient temperature increment ($G$) of $0.1°\mathrm{C}/\mathrm{cm}$ is recommended for limestone concrete. The cooling rate ($F_{\mathrm{CR}}$) range of $2.2°\mathrm{C}/\mathrm{day}\le F_{\mathrm{CR}}\le 5.6°\mathrm{C}/\mathrm{day}$ is suggested. $T_R$, $G$, and $F_{\mathrm{CR}}$ used in the equations should be validated with local concrete mixtures.