Effect in the high modulus asphalt concrete with the temperature Maria Espersson * Uppsala University, Ångströmlab, Lägerhyddsvägen 1, SE-752 37 Uppsala, Sweden highlights  25% of thickness reduction in the base layer with HMAC compared with conventional bitumen at 20 °C.  15% of thickness reduction in the base layer with HMAC compared with conventional bitumen at 0 °C.  0% of thickness reduction in the base layer with HMAC compared with conventional bitumen at 20 °C.  This study shows a clear disadvantage of using HMAC compared with conventional bitumen in cold weathers and a clear advantage of using HMAC in warm weathers. article info Article history: Received 18 April 2014 Received in revised form 23 August 2014 Accepted 27 August 2014 Keywords: Runways Airports High modulus asphalt concrete abstract The use of the high modulus asphalt concrete in the base course of airport pavements is not of recent uti- lization, but at present there is a considerable gap in the regulation for the use of this bitumen. The main objective of this paper is to present the results of the research that has been done using the experimental dynamic modulus of different mixtures of conventional bitumen with different penetration index B40/50, B60/70, B100/150, B150/200 and the high modulus bitumen B13/22 to calculate the percentage of reduc- tion in thickness of the base course in airport pavements when is used High Modulus Asphalt Concrete (HMAC) compare with conventional bitumen mixtures and is also taken into account the temperature. In order to obtain the reduction in thickness depending on the temperature and the use of HMAC, the tests have been performed at the different temperatures 20 °C, 10 °C, 0 °C, 10 °C, 20 °C and all the results in this paper are presented for these temperatures. To perform the calculations of this research the Airbus A380 has been taken as Aircraft Design. Ó 2014 Elsevier Ltd. All rights reserved. 1. Introduction The design of roads is made taking into account the number and types of heavy vehicles circulating. The design of airport runways is made basically depending on four factors: Operational Capacity, Runway Length, Airport Classification/Design Standards and Wind Coverage. For the design of both runways and roads, it is very important the material selection. And this material selection depends on several factors, for example soil properties, water con- dition or traffic type. In the eighties, a French company started to develop what today is known as high modulus asphalt concrete. The result was what today is known as Mixtures of High Modulus Asphalt Concrete (HMAC). Nowadays, the introduction of new materials for the construction of roads and runways has improved the quality of the pavement. HMAC has made an important contribution to the structural design of pavements due mainly to its good anti-rutting properties. HMAC allow the construction of base layers of, most resistant pavements to be more rigid (higher modulus) and more resistance to fatigue. This bitumen allows the building of base layers of pave- ments which are longer-lasting, or to decrease the thickness of pavements manufactured with conventional bitumen, with the resulting savings. For instance, the use of HMAC in pavement rein- forcement has the advantage of avoiding the complete removal of old bituminous layers, as HMAC make possible to reduce the thick- ness of the pavement [1]. At present despite all the advantages of the high modulus asphalt concrete there is a considerable gap for the use of this bitu- men and the real reduction in thickness for the base layer depend- ing on the temperature with the use of HMAC compare with conventional binders. This paper shows the results of the experi- mental research that has been done to calculate the reduction in thickness of the base layer with HMAC compare to a base layer with conventional bitumen for runway pavements at the different temperatures 20 °C, 10 °C, 0 °C, 10 °C, 20 °C. The program used http://dx.doi.org/10.1016/j.conbuildmat.2014.08.088 0950-0618/Ó 2014 Elsevier Ltd. All rights reserved. ⇑ Current address: Institution for Science and Technology, Uppsala University, Ångströmlaboratoriet, Lägerhyddsvägen 1, Box 534, 751 21 Uppsala, Sweden. Tel.: +46 701679231; fax: +46 184712592. E-mail address: maria.espersson@angstrom.uu.se Construction and Building Materials 71 (2014) 638–643 Contents lists available at ScienceDirect Construction and Building Materials journal homepage: www.elsevier.com/locate/conbuildmat