# Advances in the Study of the Behavior of Full-Depth Reclamation (FDR) with Cement
Although FDR with cement is, in principle, more widely used on roads with traffic of low intensity [3; 16; 23], good results have also been obtained in some of the trials conducted on roads with high-intensity flows of heavy vehicles [8; 19]. However, it must be taken into account that these pavements are being designed based on the assumption that FDR with cement and soil-cement exhibit similar behavior, but it differs due to the inclusion of reclaimed asphalt pavement aggregates in their blend, which reduces the stiffness and strength of the mixture [8; 14; 24]. Therefore, to verify this hypothesis, the long-term characteristics of the recycled material must be determined, as they have only been estimated to date [4]. In 2001, [PERSON] et al. [25] reported the results of an analysis of the mechanical properties of recycled pavements with different granular and bituminous mix percentages and 3% and 5% cement. The aim was to determine the effect of the bituminous mix percentage and temperature on the strength of the recycled pavement with cement. Compressive, tensile, flexural, and fatigue strength values were found for a small number of one and 60 day specimens. The authors determined that both compressive strength and the modulus of elasticity declined with rising bituminous content. At the same time, they concluded that flexural and tensile strength did not fall at low proportions of bituminous mix, but did so very quickly at higher contents. In 2008, [PERSON] et al. [26] published a preview of the unconfined compressive strength (UCS), indirect tensile strength (ITS), and flexural strength (FS) results that form part of the first phase of this study. Since then, the number of trials conducted has grown significantly. In FDR, the most used test to verify that material was manufactured correctly is the unconfined compressive strength (UCS) test at short-term [10; 27; 28; 29; 30]. But, in order for a better long-term characterization, it is necessary to perform flexural strength tests, and, more specifically, the four-point flexural beam test [8; 31; 32; 33; 34; 35; 36; 37; 38]. This FS test is carried out using prismatic specimens and manufacturing them requires a high level of qualification and experience within the testing team [10; 39]. This is the main reason for usually estimating their behavior from standardized tests, such as the unconfined compressive strength and the indirect tensile strength (ITS) tests [31; 40; 41; 42]. For this reason, the method used in this research is the one proposed by the University of Burgos [33]. This research aimed to fill the void in the understanding of the relationships among flexural strength, unconfined compressive strength, and indirect tensile strength based on the results of the tests conducted. To this end, the methods used for other materials mixed with hydraulic binders [33; 34; 40; 43] and the tests described by [PERSON] et al. [25] were taken as a starting point. Here, however, the applicable European (EN) or Spanish (UNE or NLT, as appropriate) standards were used to characterize the behavior of an FDR with cement. The accuracy of the initial hypothesis of similarity with soil-cement and cement-bound granular material was also evaluated.