Performance-optimised design of sand fog seal for pavement cold repair using RSM I-optimal methodology

ABSTRACT

Sand fog seal is a preventive maintenance material to repair the early distresses in asphalt pavements. The objective of this study is to develop an optimal design guideline for sand fog seal to balance the demand for rapid traffic opening with the need to keep good road performance. Based on the response surface methodology (RSM) and I-optimal methodology, the effects of the components’ ratios (including water, filler, and sand) and their interactions on the curing process and surface function of sand fog seal were investigated. The test results showed that water can regulate the fluidity and dispersibility of the fresh sand fog seal mortar, but will prolong the curing process. The modified sodium bentonite, as the filler, can shorten the full curing time of sand fog seal due to its good moisture absorption and permeability. Moreover, the interaction of water and filler significantly affected the bonding strength, and the recommended water-filler ratio was 1.5. The sand content should be controlled to less than 25% to ensure good adhesion and abrasion resistance. Finally, a formulation design guideline for sand fog seal based on desirability optimization methodology (DOM) was proposed, with recommended formulation of 21.8% water, 30% filler, and 25% sand.

KEYWORDS:

• Pavement cold repair
• sand fog seal
• I-optimal design
• response surface methodology
• curing process
• performance balance

Disclosure statement

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

Additional information

Funding

This research was supported by the National Key Research and Development Program of China [grant number 2021YFB2601000], the National Natural Science Foundation of China (NSFC) [grant number 52078048], and the Fundamental Research Funds for the Central Universities [grant number CHD 300102212708]. Moreover, the financial support provided by the Ministry of Higher Education, Malaysia via the Fundamental Research Grant Scheme [project code: FRGS/1/2021/TK01/USM/02/1] is also much appreciated.