Research Article Optimization of CLS Content of Asphalt Mixtures Based on Balanced Mix Design Approach Seyed Ali Ziaee , 1 Seyed Saeed Fatemi , 1 Hamid Shaker , 2 Mahmoud Ameri , 2 and Seyed Amir Saadatjoo 2 1 Department of Civil Engineering, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad, Iran 2 Department of Civil Engineering, Iran University of Science and Technology, Tehran, Iran Correspondence should be addressed to Seyed Ali Ziaee; sa-ziaee@um.ac.ir Received 7 January 2023; Revised 7 April 2023; Accepted 17 April 2023; Published 3 May 2023 Academic Editor: Nur Izzi Md. Yusof Copyright©2023SeyedAliZiaeeetal.TisisanopenaccessarticledistributedundertheCreativeCommonsAttributionLicense, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Over the years, there have been many studies on the performance improvement of asphalt mixtures using diferent materials and additives, especially those of the recycled variety, because of the environmental benefts they bring to the design. Tis study investigated the properties of asphalt mixtures made with diferent amounts of calcium lignosulfonate (CLS), which is a waste product, and used the Balanced Mix Design (BMD) approach to determine the appropriate mix design for CLS-containing mixtures. In this process, the results of the dynamic creep test were used as a measure of rutting resistance, the results of the indirect tensile test were used as a measure of moisture susceptibility, and the results of the Illinois Flexibility Index Test (IFIT) and Indirect Tensile Cracking Test (IDEAL-CT) were used independently as a measure of cracking resistance. On the other hand, since previous studies have suggested that CLS has antiaging properties, the specimens were made and tested in two groups: those with long-term aging and without long-term aging. So the objective was to determine the amount of CLS that should ideally be used as a bitumen additive in aged and unaged asphalt mixtures. Te results showed that using 15% or 20% CLS will always yield acceptable outcomes in terms of BMD criteria for both aged and unaged conditions. However, a CLS content of 10% may also be acceptable for both aged and unaged conditions if IDEAL-CT results are used as the measure of cracking resistance. 1. Introduction Roads are a primary type of transportation infrastructure that plays a fundamental role in making and keeping des- tinations accessible. An important part of any road that tends to have a signifcant impact on its quality and comfort is the pavement. Road pavements can be made with a variety of mixtures, among which the top choice is asphalt mixtures because of their good performance, comfort, and ease of construction and maintenance [1]. Asphalt mixtures consist of two main components: bitumen and aggregate. Naturally, any change in the properties of these two components will afect the properties of the produced mixture. Although bitumen constitutes a relatively smaller portion of an asphalt mixture, its modifcation can have great impacts on many properties and potential failures of the mixture [2]. Te properties of bitumen can change with temperature and time. Because of this dependence, it is crucial to keep track of a phenomenon called aging, which refers to changes in certain properties of asphalt mixtures during their con- struction and service life [3]. Bitumen aging is studied at two levels: short-term and long-term. Short-term aging occurs at high temperatures during the production, transportation, spreading, and compaction of asphalt mixtures. Long-term aging, however, takes place inside the asphalt over time. Te aging process generally involves the transformation of bi- tumen’s polar and soluble compounds to asphaltene, which will result in reduced bitumen mobility and greatly increased stifness of the asphalt mixture [4–6]. Eventually, these changes in the constituent parts of the asphalt mixture cause the pavement to undergo fatigue fracture under trafc loads [7]. Hindawi Advances in Civil Engineering Volume 2023, Article ID 7594186, 14 pages https://doi.org/10.1155/2023/7594186