Multi-scale Simulation of Time- Dependent Deformation Behavior of Reinforced Concrete Bridge Decks with 3-Dimensional Material-Structure Coupled Analysis
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Date
2020-02
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
A concrete structure subjected to a load deform in both immediate and with time. Timedependent
deformations
are
caused
by
the
coupled
effect
of
sustained
stress
and
stress
due
to
environmental conditions (temperature and relative humidity). The effects of these
actions are a basic creep, drying creep and shrinkage. In this research, the time-dependent
deformation behavior of the T-girder bridge deck due to the coupled effect of sustained
truckload and environmental conditions was investigated by material-structure coupled
analysis.
A full 3-dimensional T-girder deck was modeled, discretized and analyzed in finite
element package DuCOM-COM3 for material-structure coupled analysis. The standard
truckload, annual average ambient temperature and relative humidity of Addis Ababa and
Semera were used for this study.
The results of this study indicated that temperature and relative humidity significantly
affect the strength and deformation properties of the concrete. For the mix design of the
compressive strength of 30MPa, incorporating the effect of temperature and humidity, the
compressive strength of 42MPa was attained at the environmental condition of Addis
Ababa with an annual average temperature of 23.5°C and relative humidity of 64.2%. For
the same mix, the strength reduces to 30MPa at the environmental condition of Semera
with an annual average temperature of 34.3°C and relative humidity of 47.7%.
Deformation of interlayer pores and incomplete hydration due to moisture migration at an
early age was observed as the cause for the strength reduction and increase in deflection
of girder in the long term. It was observed that with the effect of ambient temperature and
relative humidity, the increase in mid-span deflection up to 4 times as large as the value
due to only sustained load without the effect of environmental conditions.
The results have shown that the deformation of interlayer pores at an early age crack was
found significant for the larger size. The reduction in strength properties of the girder deck
up to 14% was observed when compared to the cube specimen at a temperature of 34.3°C
and relative humidity of 47.7%.
Description
Keywords
Multi-scale modeling, Time-dependent deformation, Creep, Shrinkage, Environmental conditions, Moisture migration, DuCOM-COM3, Material-structure