On April 12, 2017, China Ministry of Transport issued the first People’s Republic of China transport industry standards for soils subgrade IC specifications for highway construction. The Chinese title is “公路路基填筑工程连续压实控制系统技术条件》（JT/T 1127-2017” with the official English title as “Technical condition for continuous compaction control system of fill engineering of subgrade for highway”. The starting date to implement this standard is August 1st, 2017. The team lead for developing this standard is the Treasurer and Secretary of IICTG (International Intelligent Construction Technologies Group), Prof. Guanghui Xu of Chinese Southwestern University.
The contents and requirements of this standard is consistent with the Chinese Soils IC specification for highspeed rail road bed construction that was implemented since June 1st, 2015. The key features are as follows:
- The ICMV is mechanistics-based, Vibratory Compaction Values (VCV). It is similar to Evib (used by BOMAG and Dynapac) and Kb (used by Ammann).
- For the trial section, the number of in-situ spots is more than 18 and the correlation (R) between spot test values and VCV should be greater than 0.7 (i.e., R^2 > 0.5).
- Stable vibration frequency (±0.6Hz) and relatively constant roller speeds (5～3.0km/h) are required.
- Onboard displays of compaction levels, uniformity and stability are required.
- Data files are in protected mode to avoid any alteration.
- Wireless data transmission to the Cloud is required.
It is expected the IC implementation for highspeed rail bed and highway soils subgrade construction will be accelerated in China in the near future. The asphalt IC implementation is expected soon, too.