## 1 Introduction
Results from these tests are compared respectively, to the threshold limits established by the Environmental Protection Agency (EPA, Washington, WA, USA) and those summarized in the 2003/33/EC Council Decision (EU, 2003), where in the criteria for acceptance of waste at landfill are established. However, logically, a single test cannot provide all the information that is sometimes required, but a few carefully selected tests will be sufficient [24]. Many leaching tests have been designed within different fields with slightly different purposes for different materials. Currently, there is a trend to harmonize leaching standards and test methods within the different European regulations for evaluating waste materials and products-beneficial use according Construction Products Regulations in each Member State [25]; Disposal according with Landfill Decision [26], and future regulation on End of Waste criteria [24]. In this way, in order to link the leaching behavior of the residual material and the exposure conditions, the European standardization organization has developed a framework for application of leaching tests, EN 12920 \"Characterisation of waste-Methodology for the determination of the leaching behavior of waste under specified conditions\". It is applied in a disposal or utilization scenario within a specified time frame. The methodology is designed to ensure that the specific properties of the waste and the conditions of the scenario are taken into account. The methodology contains several stages, in some of them leaching tests are used. The selection of tests is carried out depending on the objective, that is, the definition of the problem and the search for the solution, the waste under consideration and the scenario to evaluate [27]. In this context, the different leaching tests for the basic characterization of residual material have been selected based on previous recommendations and are important for assessing the release of pollutants into ground and surface water [28]. The leaching behavior depends on several variables such as leachant composition, contact time, and the liquid-to-solid ratio [29]. Equilibrium-based batch tests are low cost because they are relatively simple and rapid and they are normally used as a simple tool for compliance and/or quality control. If leaching under equilibrium-based batch tests occurs at levelsof potential environmental concern, pH dependent testing can also be conducted [30]. Total availability for leaching is an important parameter that depends on the matrix and mineralogical phases [31]. The pH dependent leaching test is a valuable tool to characterize the basic chemical leaching behavior over a wide range of pH values (much broader than the typical intended use conditions). The pH dependent leaching test provides data on the behavior of pollutants in relation to pH and the results can be used in geochemical modeling to identify solubility controlling processes [32; 33]. Identifying the chemical processes that occur in leaching will allow considering different options to improve quality and also making a prior estimate of the effects of changes in pH, such as carbonation, on the emission of pollutants [34]. The majority of pollutants show amphoteric behavior, while in some cases oxyanions may also be present and show a different behavior [22; 35]. Understanding the mechanisms of leaching and the speciation of individual contaminants is essential for predicting the long-term immobilization of pollutants in waste materials [36]. Modeling and numerical simulation has become essential for environmental risk assessment. There are few studies in the literature on the effect of EAFD on the properties of OPC and blended cement concrete, with satisfactory results [6; 14] unless the objective is to develop a concrete set retarder, as shown in the work recently published [15]. Due to the hazardous nature of EAFD, its use in civil construction should be based on solidification/stabilization technologies.