Investigation of the matric suction role on the curing mechanism of foamed asphalt stabilised mixtures

Abstract

Moisture content is of great importance for foamed asphalt stabilised mixtures, since it influences mixing, compaction, curing process and the structural performance. The curing process, in which water evaporates, is responsible for the increase of the bearing capacity of foamed mixtures. Although different loading resistance mechanisms contribute simultaneously to the layer stiffness, the aim of this research is to evaluate the influence of matric suction in the stiffness of two foamed asphalt mixtures that have been used as base course materials in experimental test sections. Filter paper, X-ray microcomputed tomography and triaxial resilient modulus tests were conducted at four moisture conditions. The filter paper test indicated an increase in the matric suction when water evaporated from the specimen, which was validated by the reduction of the air voids measured with microcomputed tomography. From triaxial resilient modulus and matric suction results, it was observed that although other mechanisms might be dominating the loading resistance of foamed mixtures, the matric suction influences the stiffness of these materials.

Keywords:

• moisture
• experimental test section
• suction pressure
• X-ray microcomputed tomography
• triaxial resilient modulus

Acknowledgements

The authors would also like to acknowledge Copavel Consultoria e Engenharia Ltda. for the availability of the vibratory compactor equipment and Arteris for the materials and the construction of the experimental test section.

ORCID

André Kazuo Kuchiishi http://orcid.org/0000-0002-5039-4525

Kamilla Vasconcelos http://orcid.org/0000-0003-4305-4829

Liedi Legi Bariani Bernucci http://orcid.org/0000-0002-4768-0993

Additional information

Funding

This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Finance Code 001, by CNPq and by ANTT.