Good Morning I’m Andrea Baliello and I’m a civil engineer. I’m attending a PhD course at the Department of Civil-Environmental Engineer and Architecture at the University of Udine and today I will show you a presentation titled «Aesthetic Transparent Road Pavements for Urban Heat Islands Mitigation and Landscape Preservation».

Urban Heat Island Urban Heat Island – UHI 1 Negative impacts related to urbanization is an increasing concern capturing the attention of people worldwide Urban Heat Island – UHI Temperature distribution 33°C Rise in temperature related to anthropized activities, manifested in any urban area where surfaces are prone to release large quantities of heat. 32°C 31°C 30°C UHI negatively impacts humans and associated ecosystems located far away from cities. 29°C Urban heat island generally identify all phenomena related to temperature rising manifested within urban areas, where surfaces are prone to release large of quantities of heat, which can negatively affect humans health. On the left side, you can see an example of a typical temperature distribution across city, suburban and rural areas, with significant difference on heat distribution (difference in mean temperatures up to 3 – 4 degrees). UHIs are indirectly related to climate changes (contributing to greenhouse effect and global warming).  Rural Suburban Commercial City Residential Park Suburban Farmland

2 Urban Heat Island Negative impacts related to urbanization is an increasing concern capturing the attention of people worldwide Urbanization Road Pavements Around half of the world human population lives in urban areas. Dark asphalt pavements cover a high percentage of the urban area, largely affecting the development of the UHI phenomenon. A C Nowadays, population migration from rural to urban/suburban areas is still continuing. Generally, they are realized with high-emissivity materials responsible of heat concentration enhancing. In 2030, it is expected that global urbanization rate will increase by 70%. As example, conventional asphalt pavement could reach over 60 °C with hot summer climate. UHI Main Causes Mitigation Strategies Lack of vegetation inhibiting radiation interception and shade production. Urban Heat Island is generally connected to urbanization phenomenon. This is an increasing concern capturing the attention of people worldwide, since it is still continuing. In two thousand thirty, it is expected that global urbanization rate will increase by 70%. Principally, UHI main causes concern all anthropized activities, but, in general, they are related to the lack of vegetation and the large amount of buildings with non-reflective surfaces, but also to the presence of the dark surfaces of roads. In fact, road pavements cover a high percentage of the urban area and are realized with high-emissivity materials. As example, during summer, a conventional asphalt pavement could reach temperature of sixty degree. Thus, a successful mitigation strategy can be addressed also at developing new clear or colored road pavements designed with innovative methods and materials. Vegetation preservation/requalification with natural area in the proximity of urban center. Buildings presence, with high-percentage of non-reflective and water-resistant surfaces tending to absorb radiations. Cooling building roofs and surfaces with new designs and materials. Narrow buildings arrangement, causing the radiation entrapment and obstructing the air flow. B D Realization of Innovative Road Pavements (e.g. Colored/Transparent) able to lower the heat concentration and diffusion.  NEW PAVEMENT MATERIAL AND DESIGNING METHODS Dark surfaces of road infrastructures. Urbanized area pollution related to waste production, conditioning/refrigeration systems and industrial processes.

Landscape Preservation 3 Landscape Preservation Colored Pavements Landscape preservation: example of red asphalt mixture. Paving operations in a mountain Italian road Infrastructure Insertion Despite of its social connotation, each road infrastructure produces relevant impacts on the landscape. Actual consciousness addressed to landscape preservation leads to consider this kind of impacts as one of the most relevant parameter, even determining the global performance of road infrastructure. Sustainable solutions could be achieved utilizing both specific design guidelines and adequate materials. Colored Pavements Colored pavements represent a promising way to promote this preservation, guarantying a sustainable insertion of the road in the landscape. Moreover, a colored pavement could represent a promising way to promote landscape preservation, contributing to guarantee a sustainable insertion of road infrastructure in the landscape. On the left side, for example, you can see some paving operations with red asphalt. In particular, this work was realized in an Italian mountain village, so an area with high landscape value. Actually, they are slightly diffused (the majority are used in areas with landscape value, as example mountain villages). Improving the visibility in several light conditions, colored pavements are useful also to improve road safety. They could be realized with several techniques, that determine the final chromatic performance (as examples: modified asphalt mixture with oxides or with innovative binders and aggregate, painting, etc…).

4 Experimental Plan Rheological Assessment STUDY OBJECTIVE Preliminary Phase: Characterization of resin mastics useful to produce transparent road pavements Dynamic tests comparing the rheological characteristics of synthetic transparent resin with those of organic bitumen. Chromatic Assessment Visco-elasticity evaluation: DSR amplitude sweep – Oscillatory test; Fr.: 1.59 Hz; Def: 0.01 to 100%; T.: 34°C. Mid-service temperature properties: DSR freq. sweep – Oscillatory test; Fr.: 0.1 to 100 rad/s; Def: 0.05%; Temp: 16 to 48°C. Rutting analysis: DSR multiple sweep creep recovery – Rotational test; τ: 0.1-3.2 kPa; 10 cycles (1s creep, 9s recovery); T.: 58 °C. Dynamic Shear Rheometer So, given this introduction, today I will present you an experimental characterization of an innovative transparent road. In particular, I’ll show a preliminary study that characterize synthetic transparent resin and mastics useful to produce this kind of pavement. This experimental plan was split in two parts. The first one, concerning a rheological assessment of medium and high service temperature properties of materials. The second one, about a chromatic analysis of this resin, with the evaluation of tone/shade/ lightness and dominant color through a Digital Image Analysis . Chromatic test comparing the characteristics of synthetic resin with those of organic bitumen. Resin color evaluation: Digital image analysis, Tone/Shade/Lighting and Dominant color – Un-aged, RTFO-aged, PAV-aged. Mastic color evaluation: Digital image analysis, Tone/Shade/Lighting and Dominant color – Un-aged, PAV-aged. Digital Image Elaboration

Materials - Sample Preparation 5 Materials - Sample Preparation Maintaining constant binder-filler volumetric proportions to ensure analogue coating mechanisms Binder volumetric dosage 73 % * Fillers 27 % FILLERS BINDERS Limestone Specific Weight: 2.74 Mg/m3 – Natural rock L Bitumen Specific Weight: 1.01 Mg/m3 P Steel Slag Specific Weight: 3.86 Mg/m3 – Recycled S Resin Specific Weight: 0.72 Mg/m3 R Cement Specific Weight: 3.15 Mg/m3 – Natural rock C * According with Superpave specifications Binder and fillers heated at 150 °C for 2 hours. Mechanical blending of binder and filler at 150°C to obtain homogeneous mastics. Basalt Specific Weight: 2.77 Mg/m3 – Natural rock B Materials are here indicated. We studied synthetic resin in comparison with traditional bitumen and different kind of fillers, in order to prepare different mastics. In particular, natural limestone and basalt, cement and recycled steel slag. As you can see, volumetric proportion was dosed at 73 % of binders and 27 % of filler aggregates, according with Superpave specifications. MASTICS RL Resin-Limestone Mastic RS Resin-Steel Slag Mastic RC Resin-Cement Mastic RB Resin-Basalt Mastic

Rheological Results: Medium-Temperature Service 6 Rheological Results: Medium-Temperature Service Evaluation of binder responses: from 16 to 48 °C. Analysis of Linear Visco-Elastic (L.V.E.) Domain – Amplitude sweep tests (strain varying from 0.01 to 100%) at 1.59 Hz of freq. Rheological Responses – Frequency sweep tests (frequency varying form 0.1 to 100 rad/s) at 0.05% of def. Bitumen Synthetic Resin Linear Visco-Elastic Domain (L.V.E.) Black Diagram 10 0 10 3 10 5 10 7 10 9 90° 70° 50° 30° 10° Phase Angle Complex Modulus 0.01 1 0.1 10 100 101 103 106 104 105 102 Strain Shear Stress L.V.E. Identified with 95% G* decrease: - Bitumen: 8.00 % - Resin: 50.1 % L.V.E. L.V.E. Rheological Response Time-temperature superposition elaboration: - Bitumen: Viscous properties - Resin: Simple thermo-rheological behavior NOT RECOGNIZED Rheological results at medium temperature are expressed in graphs. On the left, is represented the linear visco-elastic domain of resin and bitumen. Bitumen gave a linear visco-elastic limit of about 8.00 %, whereas resin of about 50%, thus it could be supposed that resin had a high elasticity. On the right graphs, are reported the Black Diagram of bitumen and resin. As expected, bitumen showed a simple thermo-rheological behavior (so the aligned grey line). Instead, resin (the orange curves) seemed to did not follow this scheme. Thus, although we demonstrated different rheological behaviors of these two material, resin had comparable stiffness values with those of bitumen.

Rheological Results: High-Temperature Service 7 Rheological Results: High-Temperature Service Evaluation of high temperature behavior in terms of rutting potential (permanent deformation resistance) Jr : Recovery Creep Compliance at 58 °C Bitumen Strain Bitumen Resin Creep Test: cycle example (τ:3.2kPa, T: 58°C) εmax Resin 70% Jr: Recovery Compliance. Normalized elastic recovery:  HIGH-ELASTIC RESIN 34.1 23.5 εstart εend 60% εmax 1.73 5.43 τ: 3.2 kPa εstart εend Rutting Response Traditional G*/sen δ evaluation:  SIMILAR MATERIAL TRENDS 50% τ: 0.1 kPa 1 sec 10 sec Then, some resin’s benefits related to high temperature service could be evinced with creep recovery tests, so analyzing the permanent deformations. On the right, you can see, in orange, the higher attitude of resin to deformations recovery, that can be probably due to the higher elasticity of the material. Also accounting the recovery creep compliance and the rutting resistance indexes, the orange bars on the left, you can see the ability of the resin to prevent the rutting potential typical of the higher temperatures. Bitumen G* / sen δ: Rutting Resistance Index at 58 °C Resin 34.9 kPa 31.5 kPa High elasticity of resin able to mitigate permanent deformation (rutting) potential 9.13 kPa 5.96 kPa ω: 100 rad/s ω: 10 rad/s

Chromatic Assessment Results 8 Chromatic Assessment Results Evaluation of tone/shade/lightness and determination of dominant RGB color Original Materials Bitumen Resin Resin RTFO Un-aged Resin RTFO Resin PAV Resin L: 141 Med: 141 Std: 63.6 R: 201 G: 131 B: 37 L: 126 Med: 126 Std: 91.2 R: 193 G: 113 B: 1 Bitumen Resin PAV R R L: 5 Med: 5 Std: 12.6 R: 9 G: 6 B: 2 L: 110 Med: 110 Std: 68.8 R: 178 G: 97 B: 1 P R Binders Chromatic results are reported in this slide. First line indicates all tested binders, whereas second one the utilized fillers. Tone/shade/lightness and dominant color of materials are given in the circular graph. Fillers Limestone L B Basalt L: 189 Med: 189 Std: 10.8 R: 195 G: 189 B: 175 L: 65 Med: 65 Std: 11.8 R: 71 G: 64 B: 56 Steel Slag Cement Basalt Limestone S C Steel Slag Cement L: 60 Med: 60 Std: 11.4 R: 60 G: 61 B: 58 L: 122 Med: 122 Std: 21.5 R: 133 G: 120 B: 106

Chromatic Assessment Results 9 Chromatic Assessment Results Evaluation of tone/shade/lightness and determination of dominant RGB color Mastics Un-aged RL Resin-Steel Slag Resin-Cement Un-aged RS Un-aged RC Un-aged RB L: 15 Med: 15 Std: 2.4 R: 16 G: 15 B: 20 L: 37 Med: 37 Std: 3.1 R: 52 G: 34 B: 9 Resin-Limestone RS Resin-Basalt R RC R L: 81 Med: 81 Std: 2.3 R: 102 G: 79 B: 38 L: 24 Med: 24 Std: 6.4 R: 25 G: 23 B: 26 RL RB R Un-aged PAV RL PAV RS PAV RC PAV RB In analogy, same data are plotted for mastics, prepared with limestone, steel slag, basalt and cement fillers. As you can see, the first line shows un-aged mastic, and second one aged mastics (where the resin was previously subjected to a PAV aging method, a laboratory procedure to simulate a long term aging typical of 5-6 years of service life). Then, singularly comparing chromatic results we were able to indicate some interesting findings. PAV – Aged RL RB Resin-Limestone Resin-Basalt L: 68 Med: 68 Std: 5.3 R: 94 G: 65 B: 18 L: 19 Med: 19 Std: 5.7 R: 20 G: 19 B: 10 RS RC Resin-Steel Slag Resin-Cement L: 14 Med: 14 Std: 1.2 R: 15 G: 14 B: 13 L: 31 Med: 31 Std: 4.5 R: 48 G: 33 B: 2

Un-aged Resin PAV-aged Resin 10 Results: Chromatic Assessment Aging effect on Resin color and Lightness – Simulation with PAV procedure Un-aged Resin PAV-aged Resin R R RGB dominant tone – Lightness Value RGB dominant tone – Lightness Value R:201 - G:131 - B:17 R:178 - G:97 - B:1 Lightness Lightness value: 141 Lightness value: 126 126 Lightness Original Sample 141 Original Sample R 1 245 876 pixel 1 312 655 pixel B G G B R First of all, un-aged resin versus PAV-aged resin. As you can see, there was a negligible color variation for the resin subjected to long-term aging procedure, with not significant color differences and darkening effects (so similar lightness values). 17 178 131 97 201 1 NEGLIGIBLE color variation for Resin subjected to long-term aging (normalized Pressure Aging Vessel procedure) NOT SIGNIFICANT darkening effect, with similar lightness value after long-term aging.

Results: Chromatic Assessment 11 Results: Chromatic Assessment Aging effect on Limestone Mastic color and Lightness – Simulation with PAV procedure Un-aged R-Limestone Mastic RL PAV-aged R-Limestone Mastic RL RGB dominant tone – Lightness Value RGB dominant tone – Lightness Value R:102 - G:79 - B:38 R:94 - G:65 - B:18 Lightness value: 81 Lightness value: 68 Lightness Original Sample 68 Original Sample 1 299 974 pixel Lightness 81 1 416 352 pixel B G R R G B 94 Moreover, analog considerations can be made for mastics, as examples, resin-limestone one. Thus a slight darkening effect and a not significant aging effect. 65 18 38 102 79 NEGLIGIBLE color variation due to PAV aging also in the case of mastic (e.g. Resin-Limestone) SLIGHT darkening effect, with similar lightness value after long-term aging.

Results: Chromatic Assessment 12 Results: Chromatic Assessment Filler typology effect on mastic color and lightness Resin-Limestone Mastic Resin-Steel Slag Mastic Resin-Cement Mastic Resin-Basalt Mastic Resin Limestone Resin Steel Slag Resin R Cement C Resin Basalt R L R S R B L: 126 Med: 126 Std: 91.2 R: 193 G: 113 B: 1 L: 189 Med: 189 Std: 10.8 R: 195 G: 189 B: 175 L: 126 Med: 126 Std: 91.2 R: 193 G: 113 B: 1 L: 60 Med: 60 Std: 11.4 R: 60 G: 61 B: 58 L: 126 Med: 126 Std: 91.2 R: 193 G: 113 B: 1 L: 122 Med: 122 Std: 21.5 R: 133 G: 120 B: 106 L: 126 Med: 126 Std: 91.2 R: 193 G: 113 B: 1 L: 65 Med: 65 Std: 11.8 R: 71 G: 64 B: 56 RL RS RC RB Chromatic Properties Condition: Chromatic Properties Condition: Chromatic Properties Condition: Chromatic Properties Condition: L: 81 Med: 81 Std: 2.3 Un-aged L: 37 Med: 37 Std: 3.1 R: 102 G: 79 B: 38 Un-aged L: 15 Med: 15 Std: 2.4 R: 16 G: 16 B: 20 R: 52 G: 34 B: 9 Un-aged L: 24 Med: 24 Std: 6.4 R: 25 G: 23 B: 26 Un-aged Then, comparing different color of fillers and mastics, it can be stressed that mastic dominant colors were sensibly affected by filler chromatic properties. And this fact could suggest that final road pavement colors could be principally affected by the chromatic characteristics of fine fraction aggregates. Mastic Mastic Mastic Mastic MASTIC COLOR sensibly affected by filler chromatic properties (tone/shade and lightness value)

Preliminary Phase Conclusions 13 Preliminary Phase Conclusions Colored pavement useful to A) mitigate heat concentration/diffusion, thus UHI phenomenon; B) preserve landscape beauty, could be realized with Synthetic Resin in substitution of organic bitumen. Rheological Assessment Concerning fine fraction portion (mastic): Chromatic Assessment Despite of different thermo-rheological behavior and the high-elastic attitude, resin demonstrated comparable, or even enhanced, stiffness and rutting resistance with respect to organic bitumen. So, concerning the preliminary study conclusions, we can state that: Colored pavement useful to mitigate heat concentration/diffusion, thus UHI phenomenon and – to preserve landscape beauty, could be realized with synthetic resin in substitution of organic bitumen. This principally because: - despite of different thermo-rheological behavior and high-elastic attitude, resin demonstrated comparable, or even enhanced, rheological performance (especially at the high service temperatures) - the simulated aging effects on resin did not seem to produce substantial alterations of its chromatic characteristics. Fillers Tone/Shade and Lightness seemed to strongly affect final chromatic characteristics of mastics. Long-term aging effect resulted negligible in terms of darkening effect/color alteration both for resin and final mastics.

Confirm the promising mechanical responses at the mixture scale. Verify the real effectiveness of mastic color on the final pavement chromatic characteristics. Further Perspectives of the Second Phase of the Study 14 Asses potential issues during mixture preparation and paving operations connected to. the use of the resin Analyze long-term chromatic responses of in-service road pavements. Further Perspectives (IN PROGRESS) Evaluate the efficiency of final colored pavement in terms of UHI phenomena mitigation. Concluding, further perspectives of the second phase of the study could be addressed to: Heat Distribution Analysis Thermographic assessment of colored asphalt mixtures for road pavements

Thank for your attention, and if anyone has any questions, I’ll be pleased to answer them.