Next Article in Journal
Assessment of Human Productivity Drivers for Construction Labor through Importance Rating and Risk Mapping
Previous Article in Journal
Comparative Gate-to-Gate Life Cycle Assessment for the Alkali and Acid Pre-Treatment Step in the Chemical Recycling of Waste Cotton
Previous Article in Special Issue
Behavior Evaluation of Bituminous Mixtures Reinforced with Nano-Sized Additives: A Review
Open AccessArticle

Ageing and Cooling of Hot-Mix-Asphalt during Hauling and Paving—A Laboratory and Site Study

1
Faculty of Engineering, Università degli Studi eCampus, 22060 Novedrate, Italy
2
Department of Construction, Civil Engineering and Architecture, Università Politecnica delle Marche, 60131 Ancona, Italy
3
Ufficio Geologia e Prove Materiali, Autonomous Province of Bolzano, 39053 Cardano, Italy
*
Author to whom correspondence should be addressed.
Sustainability 2020, 12(20), 8612; https://doi.org/10.3390/su12208612
Received: 12 August 2020 / Revised: 12 October 2020 / Accepted: 15 October 2020 / Published: 17 October 2020
(This article belongs to the Special Issue Sustainable Pavement Engineering and Road Materials)
In road construction, it can happen that, for different reasons, the time between hot-mix asphalt (HMA) production and paving is extended to some hours. This can be reflected in several problems such as mix cooling and temperature segregation, but also in an extremely severe bitumen ageing due to its prolonged exposure to high temperatures. This paper deals with the investigation of these phenomena both in the laboratory and on site. In particular, the first part of the research aimed at observing the influence of the conditioning time, when the loose HMA is kept in the oven at a high temperature, on the mix properties. The second part focused on the ageing/cooling that happens on site during HMA hauling, as a function of time and type of truck. Temperatures were monitored using a thermal camera and different probes, and gyratory compactor specimens were produced by sampling some HMA from the trucks every 1 h for 3 h. The results showed that HMA stiffness rises if the time when the loose mix stays in the laboratory oven before compaction increases. However, on site, the HMA volumetric and mechanical properties do not change with hauling time up to 3 h, probably because the external material in the truck bed protects the HMA core from the access of oxygen, hindering bitumen oxidation and loss of volatiles. The temperature monitoring highlighted that temperature segregation, after 3 h hauling, can be higher than 30 °C but it can be reduced using insulated truck beds. View Full-Text
Keywords: hot-mix asphalt; ageing; cooling; temperature segregation; hauling; insulated truck; re-heating hot-mix asphalt; ageing; cooling; temperature segregation; hauling; insulated truck; re-heating
Show Figures

Figure 1

MDPI and ACS Style

Bocci, E.; Prosperi, E.; Mair, V.; Bocci, M. Ageing and Cooling of Hot-Mix-Asphalt during Hauling and Paving—A Laboratory and Site Study. Sustainability 2020, 12, 8612.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Search more from Scilit
 
Search
Back to TopTop