Document Type : Scientific - Research
Authors
1
School of Civil Engineering, Iran University of Science and Technology, Tehran, Iran
2
Department of Civil Engineering, Iran University of Science and Technology (IUST), Narmak, Tehran, Iran
3
Department of Civil Engineering, University of Tehran, Tehran, Iran
Abstract
Pigmented surface treatments are widely used to organize urban spaces (i.e., bike and pedestrian lanes, special lanes, or traffic mitigation measures) and improve the visibility and traffic safety. The present study was performed to investigate the performance and mix design of pigmented slurry seal containing bitumen emulsion and natural pigments replacing natural filler. In this respect, first, characteristics of the powdery pigment and natural filler were investigated by means of XRF, XRD, BET, and FESEM analyses, with the bitumen-filler interactions examined through FTIR tests. Next, 7 pigmented compounds containing red, yellow, and blue powdery pigments (particle size smaller than 0.075 mm) combined with TiO2 were used to partially replace natural filler. Evaluation and comparison of the asphalt samples were performed through wet cohesion test, wet track abrasion test, loaded wheel-sand adhesion test, and loaded wheel-displacement test, with the colorimetric characteristics determined by a spectrophotometer. Results showed that the mixture containing red pigment exhibits the best performance, as compared to other asphalt samples, producing 8.1 and 7.6% higher cohesion than the control sample upon 30 and 60 min of test time, respectively. It further decreased the moisture sensitivity of mixture by 27.6% and vertical displacement under traffic loading by 11.7%. Colorimetric characterization results showed that the use of the TiO2 led to appropriate results when its dosage was limited to 1 – 3% for the blue and red blends and 1% for the yellow blend.
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