Development of non-contact 3D measurement of areal pavement texture parameters

Abstract

This research used the non-contact method of Close Range Photogrammetry (CRP) to investigate its ability for the 3D capture of pavement surface texture. The Millar (2013) CRP method was further developed for 3D capture over megatexture, macrotexture and microtexture scales. Analysis was carried out using the harmonised European Standard EN ISO 25178-2 (2012) regarding areal texture characterisation.

Research method work flows were developed to cover the stages involved from image capture to analysis of the 3D model. These include use of the software, creation of TINs, file conversions and areal analysis. Issues regarding camera settings, lighting, image resolution, use of control frameworks, and surface noise were optimised for each texture scale.

Changes to pavement surface texture subjected to simulated trafficking were quantified at the megatexture, macrotexture and microtexture scales. 3D models were made at stages during simulated trafficking and their surface parameters determined. It was found that the interactive Abbott Firestone curve (Vmp) study in Mountains Map was the most versatile non-contact method of analysis.

A new non-contact 3D model measure of macrotexture termed threshold mean texture depth (TMTD) was found to correlate well with the volumetric patch technique derived mean texture depth (MTD). The preferred method for recovery of macrotexture was with the use of the CRP method and vinyl replicates.

The CRP method was used to assess aggregate microtexture change of PSV test specimens. It was found that the 3D surface of different aggregates differed in their response to the polishing conditions. The friction tester FTV was found to have weak correlations with areal parameters Vmp80, Sa and fractal dimension. Assuming that the 3D model parameters accurately reflect the test specimen surface, the lack of correlation between friction tester and areal parameter requires further research.

CRP was used to model tyre draping. A new TyDra3D method was developed to investigate how rubber deforms around individual grains, crystals, the edges of individual particles and across their surface. This has application in all types of tyre / pavement surface texture interaction e.g. skid resistance, road surface noise and rolling resistance.

Date of Award	Mar 2015
Original language	English
Sponsors	Department for Employment and Learning, Northern Ireland
Supervisor	David Woodward (Supervisor), Phillip Millar (Supervisor) & Donal Ryan (Supervisor)