Procedia Materials Science 1 (2012) 425 – 431 2211-8128 © 2012 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of SAM/CONAMET 2011, Rosario, Argentina. doi:10.1016/j.mspro.2012.06.057 11 th International Congress on Metallurgy & Materials SAM/CONAMET 2011. Refractory concretes of chemical bond with diverse aggregates N. Hipedinger a,b, *, A. Scian a,c , E. Aglietti a,c a CETMIC: Centro de Tecnología de Recursos Minerales y Cerámica (CIC–CONICET), Camino Centenario y 506, 1897 Manuel B. Gonnet, La Plata, Argentina. b Departamento de Construcciones, Facultad de Ingeniería, Universidad Nacional de La Plata, 115 y 48, 1900 La Plata, Argentina. c Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, 115 y 47, 1900 La Plata, Argentina. Abstract In this work three cold-setting refractory concretes using the chemical magnesia-phosphate bond were prepared. A mixture of calcined alumina, microsilica, magnesium oxide and phosphoric acid was designed to form cordierite during the heating. This cementitious paste acts like a matrix in which the aggregates are embedded. Three different aggregates were used: cordierite-mullite (C), mullite chamotte (M) and tabular alumina (T) with the objective to analyze its behaviour and the matrix-aggregate interaction. These concretes set at room temperature, being observed by XRD, in addition to the typical reflections of each aggregate, the presence of MgHPO 4 ·3H 2 O (newberyite) in low proportion and predominantly amorphous phase. At 110 °C were not detected crystalline hydrated phosphates. At 1100 °C was formed aluminium orthophosphate, AlPO 4 cristobalite type. At 1350 °C the matrix was transformed into cordierite-mullite, being also detected small amounts of Mg 3 (PO 4 ) 2 . Although the phases developed in the matrix during heating were similar for three concretes, performance at elevated temperatures was different. The possible causes of unsatisfactory behaviour of concretes made with aggregates of mullite chamotte and tabular alumina were analyzed. The main properties of concrete made with cordierite-mullite aggregates were presented. © 2012 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of 11 th International Congress on Metallurgy & Materials SAM/CONAMET 2011. Keywords: Refractory; Cordierite; Mullite; Alumina; Magnesia-phosphate bond * Corresponding author. Tel.: +54-0221-484-0247; fax: +54-0221-471-0075. E-mail address: norahipe@cetmic.unlp.edu.ar. Available online at www.sciencedirect.com © 2012 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of SAM/ CONAMET 2011, Rosario, Argentina.