Title:
Mitigation of Early Thermal Contraction Cracks in Massive Footings
Author(s):
Rodrigo Antunes and Mang Tia
Publication:
Structural Journal
Volume:
118
Issue:
6
Appears on pages(s):
193-200
Keywords:
degree of restraint; modulus of elasticity; temperature; tensile strength; thermal crack; thermal expansion; thermal stress
DOI:
10.14359/51733078
Date:
11/1/2021
Abstract:
This experimental research aimed to enhance thermal crack mitigation mechanisms for massive bridge footings by assessing thermal stresses (σth) associated with concrete temperatures, physical properties of concrete, and dimensions of 29 footings. Concrete mixtures for massive footing applications should be tested for modulus of elasticity (MOE), coefficient of linear thermal expansion (CTE), and splitting tensile strength (fct′) so that the σth can be anticipated and compared to the respective fct′. Although such concrete properties are often neglected, their importance to crack mitigation is paramount. The σth of bridge footings were established based on actual degrees of restraint (K), temperature variations (ΔT), MOE, and CTE, then compared to fct′. The results suggested that the enhanced crack mitigation threshold should be expressed by the maximum ΔT for which a footing’s σth/fct′ ≤ 0.25.