Title:
Apparent Thermal Coefficient of Expansion of Concrete Building with Restraint
Author(s):
Magued Iskander, Saumil Parikh, and Walid Aboumoussa
Publication:
Materials Journal
Volume:
109
Issue:
1
Appears on pages(s):
63-70
Keywords:
crack meter; elongation; expansion joint; instrumentation; joint meter; monitoring; thermal stresses; vibrating wire displacement transducers.
DOI:
10.14359/51683571
Date:
1/1/2012
Abstract:
The expansion coefficient of a four-story open reinforced concrete parking structure subjected to wide temperature variation was measured. The structure consists of a waffle-slab floor system with regularly placed columns and measures 52.42 x 71.32 m (172 x 234 ft). An expansion joint was instrumented and monitored for 4.5 years. The joint was instrumented using four vibrating wire displacement transducers with integrated temperature sensors. Transducer measurements were recorded hourly. A description of the instrumentation and monitoring results is presented, including annual, seasonal, and daily ranges of movement and the corresponding values of the apparent coefficient of thermal expansion (ACTE) of the constructed structure in service. In general, it was found that values of the annual ACTE were primarily dependent on the degree of restraint and, to a lesser extent, temperature. The measured ACTE ranged from 0.000586 to 0.0793% per 100°C (0.00032 to 0.044% per 100°F), depending on the temperature and imposed structural restraint.