Investigation of the physicochemical characteristics of ancient mortars bystatic and dynamic studies

The present work focuses on the investigation of physicochemical characteri stics of ancient mortars through the use of static and dynamic methods. Por e structure characteristics of limestone mortars are determined by means of the mercury porosimetry technique. Preliminary results show an average por e size of >900 Angstrom, indicating the major role of macropores in the mor tars. A pseudo-first order reaction-diffusion model is developed for invest igating the transport and reaction of CO2 on such samples. The model is sol ved for each isotope of CO2 and the isotopic fractionation is determined as a function of distance from the surface of the mortar. The model's results are fitted to experimental data on carbon isotopic compositions obtained o n these mortars. From the optimum fitted parameters, it follows that pore d iffusion has a significant effect on the reaction rate of CO2 on the struct ure of the ancient mortars. (C) 2000 Elsevier Science Ltd. All rights reser ved.