Thermal movements in concrete: Case study of multistory underground car park

An expansion joint in a concrete structure was instrumented and monitored for a period of one year. The structure is an open four-story car park, measuring 90 m (295.4 ft) in length and 71.62 m (235 ft) in width. It is a reinforced-concrete waffle-slab floor system with rectangular columns. 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 of the expansion joint are presented, including annual, seasonal, and daily ranges of movements 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 of the joint ranged between 0.000586% per 100°C (0.00032% per 100°F) and 0.0757% per 100°C (0.041% per 100°F , depending on the type of structural restraint imposed on the expansion joint.