Early Age Behavior of Jointed Plain Concrete Pavement inside Tunnel

Abstract

It is widely acknowledged that environmental loading, such as changes in temperature and humidity, greatly influences concrete slab movement, causing considerable strain and stress. A field construction test was conducted in order to investigate strain properties of jointed plain concrete pavement (JPCP) placed in a relatively closed section like tunnels. In this study, environmental loading in and outside tunnels was measured, and early age strain properties of concrete pavement were examined with varied slab spacing. To analyze the strains at each component of concrete pavement, Vibration Wire Strain Gauges (VWSGs) and non-stress devices were used in the field test. Base on the data measurement and calculation process, the total strain, shrinkage strain, thermal strain, and elastic strain of the concrete slab could be obtained separately. Observation data for three weeks after concrete placement indicated that the temperature difference between the top and bottom of the slab was smaller than 3°C inside the tunnel, while there was be as high as 10°C temperature difference outside the tunnel. Inside the tunnel, similar strain properties were displayed in the 6 m and 8 m slabs, where strain levels were half those of general road sections. © 2020, Korean Society of Civil Engineers.