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Published in Dean Brox, Practical Guide to Rock Tunneling, 2017
A sample list should be prepared and documented digitally that can be provided to all parties involved. All samples should be thoroughly protected with wrapping including plastic saran wrap, tin foil, bubble wrap or using simple plastic sample bags. Sample labelling should be included on all wrapping or sample bags. All samples should be packaged for transport in a box containing Styrofoam chips or bubble wrap for isolated protection of each sample to prevent any damage. Moisture or durability sensitive samples such as mudrocks (claystones, shales etc.) may warrant the preparation of each sample firstly in plastic wrap and inserted into polyvinyl chloride (PVC) sample tubes filled with melted paraffin wax.
Effect of type and particle size of superabsorbent polymers on the hydration mechanism of pavement concrete
Published in International Journal of Pavement Engineering, 2023
Yawen Tan, Huaxin Chen, Rui He, Zhe Yang
The mixture proportion of pavement concrete (C50) was designed and shown in Table 3. The IRH was monitored using sensitive temperature & humidity sensors and nominal accuracies of the sensors were ±0.2°C and ±1.5% RH. The sensor signals were monitored by a computer and recorded every minute. Specimens with dimensions of 400 mm × 400 mm ×100 mm were prepared and the device used to monitor IRH is presented in Figure 6. The sensors were embedded at intervals of 100 mm at the centre axis of the specimens. The bottom end of the sensor was located at half the height of the specimen (50 mm). Cylindrical polyvinyl chloride (PVC) with an inner diameter of 16 mm was selected and the exposed end of the PVC pipe is sealed with self-adhesive plastic wrap and tape. IRH values were recorded after 1 d and determined as the average of the daily data of three replicates using the specimens. All IRH specimens formed were firmly wrapped and monitored in the atmosphere of 20 ± 2°C and 95% humidity for 28 d after demolding.