A new empirical diffusion model for solvents in sprayed seals based on evaporation measurements

Abstract

Dr Kwesi Sagoe-Crentsil is an experienced researcher and team leader who has demonstrated excellent leadership in positioning his team and CSIRO Geopolymer research. He is the Deputy Director of Operations of the ARC Nanocomm Hub. Professor Wenhui Duan is the Director of the ARC Nanocomm Hub and an inspiring leader in the field of nanoscience-based construction materials. He has developed an innovative engagement model to motivate public researchers to connect with industry. He is the driving force behind ground-breaking work that delivers significant economic benefit in construction materials, green structures, and infrastructure asset management. A new empirical diffusion model for solvents in sprayed seals based on evaporation measurements Prediction of solvent diffusion and evaporation rate in the initial days after construction of a sprayed seal is of special concern for pavement performance assessment. It is still a major challenge as solvent evaporation is a very complicated process. In this study, laboratory tests were conducted on bitumen-solvent binder films, under different experimental conditions and varying solvent properties. A solution of Fick's diffusion equation was then used to calculate solvent diffusion coefficient (D) values for the initial 7 days. While a strong correlation was found between D and solvent viscosity as well as D and solvent distillation range, no relationship was found between D and solvent aniline point nor aromatic content. These findings were utilized in developing a multiple linear regression (MLR) diffusion model for the initial 7 days of evaporation. The evaluation of the model indicated close agreement between the predictions and experimental values (R 2 = 0.95). The model enables road agencies to predict solvent diffusion and residual solvent for the early life of a sprayed seal without needing to conduct extensive experiments thereby saving time and labour cost. Accurate prediction of residual solvent via the developed model will further ensure long-term performance of sprayed seals.

Artificial intelligence-based gene expression programming (GEP) model for assessing sprayed seal performance

“…Before starting the evaporation test, the relative solubilities of the solvents with C170 bitumen were assessed to observe if C170 bitumen was compatible with the different solvents selected for this research. Details of the compatibility test can be found in the article by Tamanna et al (2021),…”

“…Sample preparation for the evaporation test included preparing bitumen-solvent blends by mixing C170 bitumen as the main binder with 2%, 4% and 6% w/w of each of the 7 solvents as the diluent and then making 2 mm thin binder films of each of the bitumen-solvent blends in round metal dishes. To keep the work concise, details of the sample preparation can be found in our prior published work (Tamanna et al, 2021). In this manuscript, an elaborate description of the evaporation test and the following data collection procedure is articulated.…”

“…In this way, 1617 α values was obtained as a function of solvent types, solvent percentages, temperatures and times. It should be mentioned that these data have also been used in our previous paper (Tamanna et al, 2021).…”

“…Mineral turpentine, Enersol kerosene and Enersol K were selected as they could also be used to reduce the viscosity of bitumen in sprayed seals. Among the latter three solvents, Mineral turpentine was supplied by Recochem Inc whereas Enersol kerosene and Enersol K were supplied by IOR Energy Pty Ltd. A details of the composition and typical range of properties of the solvents can be found in the article byTamanna et al (2021). AS 3568-1999 properties of the solvents used in this study.…”