CHEMICAL IDENTIFICATION OF PORTLAND CEMENTS IN NEW ZEALAND CONCRETES. II. THE CA-SR-MN PLOT IN CEMENT IDENTIFICATION AND THE EFFECT OF AGGREGATES

Abstract A simple test based on a HNO 3 leach of the concrete to determine concentrations of Ca, Sr, and Mn which can be plotted on a ternary diagram, is sufficient to identify cements from four major cement works. The identification of cements from two minor abandoned works may require more accurate estimation of Ca/Sr using neutral EDTA solution. 14 Examples of New Zealand concretes serve as examples that illustrate the simplicity of the test. Greywacke, basalt, andesite and rhyolite are the aggregate types that are commonly used in New Zealand concretes. They were leached separately in order to determine their potential contribution to leachates from concrete. Application of REE distribution patterns to cement identification in hardened concrete is limited by appreciable contamination due to REE release from aggregates during leaching.