Studi numerik pengaruh suhu penempatan beton massa terhadap perkembangan gradien regangan sebagai penyelidikan awal pencegahan retak beton usia muda

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.