實驗代號
Experiment ID | 實驗名稱 | Experiment Name | 地點
Site | 設施
Facility | 實驗類型
Type | 試體材料
Material | 說明 | Description |
| Exp 1 | Time–dependent elastic modulus of concrete by compression tests
| Time–dependent elastic modulus of concrete by compression tests
| NCREE | Reaction wall & strong floor | Compression tests | Concrete cylinders
| | A set of 100 mm × 200 mm concrete cylinders were cast to measure the time-dependent elastic modulus of the high-strength concrete through compression tests. The PCI beam and all the cylindrical specimens were maintained in outdoor laboratory spaces under the same curing environmental conditions. The elastic modulus E for each cylinder was estimated using Eq. (1), in accordance with ASTM Standards C 469/C 469M–14 [31]. The measured elastic modulus values at 28 days and those recorded during the experimental period (Section 2.2) are listed in Table 1 [dataset] [33]. The average elastic moduli Eaver and Efvt,aver were calculated on each required day by testing two cylinders. Vice versa, four specimens were tested during 28 days of curing. The elastic modulus Eaver exhibited progressive increments of 1.7%, 2.3%, and 3.8% with respect to the value obtained after 28 days. Conversely, the elastic modulus Efvt,aver registered progressive increments of 11.9%, 12.2%, and 15.9%, respectively. Thus, the average reference elastic moduli were Eref = 37,444 MPa and Efvt,ref = 41,366 MPa. The higher values for Efvt,aver were caused by the lower values of stresses σ2 assumed in Eq. (1), as reported in Table 1 [dataset] [33]. The ratio Eref / Efvt,ref = 37,444 / 41,366 = 0.91 agreed with the ratio for the secant and dynamic elastic modulus of reinforced concrete beams, where the dynamic modulus was determined through transverse vibrations on a set of concrete beam specimens [34]. The mean characteristic strength fck was 96 MPa for the compression tests at the 66th, 69th, and 70th days of curing, as detailed in Table 1 [dataset] [33]. The concrete's experimental unit weight, ρc = 24.26 kN/m3, was obtained using the average of the cylinder weights shown in Table 1 [dataset] [33]. |
| Exp 2 | Free vibration testing
| Free vibration testing
| NCREE | Reaction wall & strong floor | Vibration testing
| Large–scale PCI beam with a parabolic unbonded tendon
| | Free vibration tests were performed following application of prestress forces N0x,aver. Three test cases with N0x,aver of 1658, 1829, and 1952 kN were examined. All the servo velocity seismometers acquired acceleration data using a sampling rate of 200 Hz and a block size of 16,384 samples (Fig. 5(c)). Vibration measurements were performed three times for each imposed prestress force N0x,aver, for a total of nine experiments. Specifically, free transverse vibrations were induced by breaking a steel rebar 10 mm in diameter anchored close to the beam’s midspan (Fig. 5(a)). The rebar’s ultimate strength fsk of 540 MPa was achieved using a hydraulic oil jack of 100 kN force capacity, pulling each rebar up until rupture (Fig. 5(a)). The hydraulic oil jack was driven by a hydraulic pump of 96.53-MPa maximum pressure capacity positioned on the floor (Fig. 5(b)). The large-scale PCI beam was thus vertically excited by a release force Fd of approximately 42.4 kN (Fig. 4) and its dynamic response was measured along the strong axis. The PCI beam did not develop any cracks during testing. The applied prestress forces N0x1 and N0x2 were recorded every second for nearly 200 seconds by a data acquisition unit using a separate data log. |