Forero Javier A, Brito Jorge de, Evangelista Luís, Pereira Cláudio
Postgraduate Program in Structural Engineering and Construction (PECC), Predio SG-12 Campus Darcy Ribeiro, University of Brasília, Brasilia-DF, CEP 70910-900, Brazil.
CERIS, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
Materials (Basel). 2022 Apr 8;15(8):2740. doi: 10.3390/ma15082740.
The main factor that alters the quality of recycled concrete aggregate (RCA) is the paste adhered to the natural aggregate (NA). Since it causes weakening of the interfacial transition zone (ITZ) between the aggregate and the cementitious paste, it becomes a determining factor for the mechanical behavior of concrete. It turns out that it is critical to enhance this interface by improving the surface of the aggregate or by removing the paste adhered to the NA. Considering the variety of methods for removing paste adhered to RCA-namely using acids such as hydrochloric acid (HCl), sulfuric acid (HSO), and phosphoric acid (HPO), among others-this paper presents a review of treatments for the removal of adhered paste using acidic solutions on the RCA, and their influence on the mechanical properties and durability of concrete produced with RCA. Pearson's correlation was used in the statistical analysis to determine the linear relationship of the main factors-for instance, immersion time, acidic solution, and aggregate size-involved in the removal of the paste in the RCA.
影响再生混凝土骨料（RCA）质量的主要因素是附着在天然骨料（NA）上的浆体。由于它会导致骨料与胶凝浆体之间的界面过渡区（ITZ）弱化，进而成为混凝土力学性能的决定性因素。事实证明，通过改善骨料表面或去除附着在天然骨料上的浆体来增强此界面至关重要。考虑到去除附着在再生混凝土骨料上浆体的多种方法，例如使用盐酸（HCl）、硫酸（H₂SO₄）和磷酸（H₃PO₄）等酸类，本文综述了使用酸性溶液处理再生混凝土骨料以去除附着浆体的方法，以及它们对用再生混凝土骨料生产的混凝土力学性能和耐久性的影响。统计分析中使用皮尔逊相关性来确定参与去除再生混凝土骨料中浆体的主要因素（如浸泡时间、酸性溶液和骨料尺寸）之间的线性关系。
