| dc.description.abstract | Preexisting cracking was observed on a pier cap structure a week after
concrete casting. External damage caused by existing cracks before being
burdened by service load may compromise further structural
performance. Several factors caused early-age concrete cracking
involving elastic modulus maturity and hydration heat generation.
Modifying concrete placing temperature is a common method to reduce
accumulative hydration heat, especially in mass concrete structural
design. Early-age concrete parameters such as elastic modulus maturity,
temperature rise, and coefficient of thermal expansion were implemented
in finite element models along with various temperature rise patterns
following ACI 207.2R-07 specification. Utilizing the finite element
analysis method could simulate strain gradient patterns caused by
thermal expansion stress, which is influenced by temperature rise. This
study demonstrated early study to reduce cracking risk by observing the
influence of concrete placing temperature variations assessed by the
strain gradient pattern and peak nominal strain. Finite element analysis
results indicated a proportional relationship between the temperature of
concrete placing and peak nominal strain with a similar potential for
cracking risk zonation. Although the method of reducing concrete
placement temperature was commonly practiced, this study showed that
the method was considered ineffective in reducing early-age concrete
cracking risk on mass concrete pier cap P87 structure. | en_US |
