Title: Assessment of cracking in concrete due to hydration heat and autogenous shrinkage

Authors: Muhammad Nasir Amin, Jeong-Su Kim, Jin-Keun Kim

Addresses: Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (KAIST), 373-1, Guseong-dong, Yuseong-gu, Taejon 305-701, South Korea. ' Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (KAIST), 373-1, Guseong-dong, Yuseong-gu, Taejon 305-701, South Korea. ' Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (KAIST), 373-1, Guseong-dong, Yuseong-gu, Taejon 305-701, South Korea

Abstract: An experimental study was conducted to simulate the generation of thermal stresses due to hydration heat and restraint by using a thermal stress measuring device (TSD). The net effects of time-dependent properties of hardening concrete can be well incorporated in TSD due to simultaneous development of temperature and corresponding stress in restrained specimen. Moreover, experiments were conducted to measure a precise value of early-age autogenous shrinkage (AS) and to evaluate the basic creep model with respect to AS. In cracking risk analysis, precise value of early-age AS must accurately predict the time of shrinkage-induced cracking. A significant difference exists between apparent (including AS) and real basic creep (excluding AS) for low water-cement ratio concrete and early-age normal strength concrete. To improve the crack sensitivity analysis, it is recommended to precisely measure early-age AS and modify the basic creep model to prevent from possible errors and computational problems.

Keywords: autogenous shrinkage; early-age shrinkage; hydration heat; thermal stress measuring; basic creep; concrete cracking; simulation; crack sensitivity analysis; structural engineering.

DOI: 10.1504/IJSTRUCTE.2010.031482

International Journal of Structural Engineering, 2010 Vol.1 No.2, pp.145 - 159

Published online: 05 Feb 2010 *

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