Effects of ambient temperature and compaction delay time on the performance of cement-stabilised sand–gravel and the determination of allowable construction delay time

ABSTRACT

Compaction delay time (t_d) refers to the period from the mixing of inorganic binder–stabilised materials to the completion of compaction; this process is affected by ambient temperature (T_a). To characterise the effects of T_a and t_d on the performance of cement-stabilised sand–gravel (CSG) during construction, the reliability of the vertical vibration compaction method (VVCM) is evaluated and the effects of T_a and t_d on the mechanical strength and freeze–thaw resistance of CSG are investigated. Next, a predictive model for the allowable construction delay time is developed based on a non-loss principle with respect to pavement performance. The results show that the correlation between the mechanical strength of CSG laboratory specimens subjected to VVCM and field core samples can reach ∼90%. Higher T_a and longer t_d significantly reduce the mechanical strength and freeze-thaw resistance of CSG. Notably, when t_d exceeds the initial setting time of cement, the average reductions in compressive strength, splitting strength, and freeze-thaw resistance of CSG are ∼29.3%, 31.3%, and 20.4%, respectively. The allowable construction delay time decreases linearly with increasing T_a, showing a correlation of up to 99%. The predictive model can effectively determine the allowable construction delay time at any temperature.

KEYWORDS:

• Subgrade engineering
• cement-stabilised sand–gravel
• compaction delay time
• ambient temperature
• vertical vibration compaction method
• allowable construction delay time

Data availability

The data used to support the findings of this study are included within the article.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research was supported by the Shaanxi Province Innovation Capacity Support Program [grant no NO.2022TD–06]; Shaanxi Province Transportation Science and Technology Project [grant no NO.20–02 K]; Zhejiang Province Transportation Science and Technology Project [grant no NO.2021042]; Department of Education Scientific Research Project of Hunan Province [grant no No. 22B0752]. The authors gratefully acknowledge all the financial support.