During operation pH and alkalinity of the input water and leachate are measured as a function of the location in the ZAP-C3 unit to determine their dependence on temperature. pH sensors are used for continuous measurement, while alkalinity is measured on collected samples of water, quenchant (carbonic acid), and leachate (bicarbonate ion solution) and titrating with 0.02N sulfuric acid using a phenolphthalein indicator. The concentration of CO2 is measured in-situ with a sensor. Chemical analysis of metals in the Leachate, pre-weathered aggregates, and weathered aggregates was performed using MP-AES (Agilent). Thermogravimetric analysis was used to determine the amount of carbonate in slag (or concrete samples) before and after mineralization . Total carbon (TC) measurements using Elementar Enviro TOC instrument provide both dissolved CO2 and inorganic carbon (carbonate) content of the pH 7 water, the acidic and alkaline solutions .