The inﬂuence of combination of binding agents on fatigue properties of deep cold in-place recycled mixtures in Indirect Tensile Fatigue Test (ITFT) Bohdan Dolzycki, Cezary Szydlowski, Mariusz Jaczewski ⇑ Highway and Transportation Engineering Department, Faculty of Civil and Environmental Engineering, Gdansk University of Technology, Narutowicza Street 11/12, Gdansk PL 80-233, Poland highlights  Fatigue properties of eight cold recycled mixtures were tested.  Indirect Tensile Fatigue Test method in controlled stress mode was used.  Obtained results showed complex fatigue behavior of tested mixtures.  Apart from amount of speciﬁc binder, also their total amount inﬂuences the results. article info Article history: Received 18 July 2019 Received in revised form 2 December 2019 Accepted 6 December 2019 Keywords: Cold recycling Recycling Mineral cement emulsion mixtures Cement Bituminous emulsion Fatigue Indirect Tensile Fatigue Test (ITFT) abstract The publication presents fatigue properties of cold recycled mixtures for eight combinations of binding agents (cement and bituminous emulsion). Cold recycled mixtures were evaluated in Indirect Tensile Fatigue Test (ITFT) at the temperature of 20 °C in controlled stress mode. As a function of horizontal stress, fatigue life is strongly inﬂuenced by combination of the binding agents. When fatigue life is ana- lyzed as a function of initial horizontal strain, the difference between different combinations decreases. In all cases, the inﬂuence of a speciﬁc binding agent is more visible for combinations with lower total amounts of the two agents. Ó 2019 Elsevier Ltd. All rights reserved. 1. Introduction 1.1. Background Deep cold in-place recycling is one of the most widely used eco- friendly technologies for reconstruction of old and deteriorated road pavements [1–3]. The most commonly used binders for aggre- gate material include combinations of cement, cement-based bin- ders, bituminous emulsion and foamed asphalt [4–6]. Laboratory and ﬁeld investigations showed that the proportion between the binding agents has signiﬁcant inﬂuence on properties of ready cold recycled mixtures [7–12]. Literature encompasses numerous research projects focused on the inﬂuence of binding agents on mechanical properties, such as stiffness modulus, strength or frost and water susceptibility, especially for short periods of curing. However, these properties do not fully describe the behavior of cold recycled mixtures in the pavement structure. Cold recycled mixtures in pavement structure, as in most cases they are used as road bases, where loads are distributed on a larger area in com- parison to asphalt courses. Therefore, not only the basic mechani- cal properties, such as strength and stiffness modulus, are important to proper performance of this layer, but also fatigue properties, which correspond to the impact of numerous small loads from all vehicle passes in the pavement life. The inﬂuence of combination of binding agents on fatigue behavior of cold recy- cled mixtures still has not been fully investigated. It is a very important factor, taking into consideration the dual behavior of cold recycled mixtures. Depending on the amount of a speciﬁc binding agent, a cold recycled mixture may present a more ductile https://doi.org/10.1016/j.conbuildmat.2019.117825 0950-0618/Ó 2019 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. E-mail address: mariusz.jaczewski@pg.edu.pl (M. Jaczewski). Construction and Building Materials 239 (2020) 117825 Contents lists available at ScienceDirect Construction and Building Materials journal homepage: www.elsevier.com/locate/conbuildmat