Abstract —In this paper, study on carbonation process of several types of advanced plasters on lime basis is presented. The movement of carbonation head was measured by colorimetric method using phenolphtalein. The rate of carbonation was accessed also by gravimetric method. Samples of studied materials were placed into the climatic chamber for simulation of environment with high concentration of CO 2 . The particular samples were on all lateral sides and on the bottom side provided by epoxy resin in order to arrange 1-D transport of CO 2 into the studied samples. The carbonation rates of particular materials pointed to the time dependence of diffusion process of CO 2 for all the studied plasters. From the quantitative point of view, the carbonation of advanced modified plasters was much faster than for the reference lime plaster, what is beneficial for the practical application of the tested newly developed materials. Keywords—Carbonation, colorimetric method, gravimetric method, lime-based plasters, pozzolana admixtures. I. INTRODUCTION HE process of hardening of lime-based plasters is driven by the reaction of CO 2 from the ambient air with Ca(OH) 2 that represents reaction product of burnt lime (CaO) hydration. The rate of carbonation is one of the decisive factors that affect the final strength and durability properties of lime-based mortars and plasters. The lime-based mortars and plasters find application in civil engineering because of their high hygroscopicity that allows optimal conditioning of buildings’ interior. The lime materials exhibit also good adhesion to the substrates, and partial self-consolidation in the case of substrate deformation. On the other hand, the lime materials have very low durability in case of their longer contact with liquid water. Here, the significant weathering of lime materials can be observed. On that account, several admixtures mainly on pozzolana basis are applied within the mix design of lime- based mortars and plasters. Z. Pavlík is with the Department of Materials Engineering and Chemistry, Faculty of Civil Engineering, Czech Technical University in Prague, 166 29 Prague, Czech Republic (phone: +420-2-2435-4371; fax: +420-2-2435-4446; e-mail: zbysek.pavlik@fsv.cvut.cz). H. Benešová is with the Department of Materials Engineering and Chemistry, Faculty of Civil Engineering, Czech Technical University in Prague, 166 29 Prague, Czech Republic (phone: +420-2-2435-4688; fax: +420-2-2435-4446; e-mail: hannah.benesova@fsv.cvut.cz). P. Matiašovský is with the Institute of Construction and Architecture, Slovak Academy of Science, 845 03 Bratislava, Slovakia (phone: +421-2-54 77-3548, fax: +421-2-54 77-3548, e-mail: usarmat@savba.sk). M. Pavlíková is with the Department of Materials Engineering and Chemistry, Faculty of Civil Engineering, Czech Technical University in Prague, 166 29 Prague, Czech Republic (phone: +420-2-2435-4688; fax: +420-2-2435-4446; e-mail: milena.pavlikova@fsv.cvut.cz). Hardening of lime mortar with addition of pozzolanic admixtures proceeds in two competitive reactions: classical carbonation (reaction of calcium hydroxide and carbon dioxide) and pozzolanic reaction [1]. The process of carbonation of pure lime mortars and plasters is nowadays well understood and experimentally researched. However, application of new materials in composition of lime materials makes the process of carbonation more complex and complicated. Therefore, experimental testing and monitoring of the velocity and propagation of carbonation must be performed in order to obtain necessary information for application of newly developed materials in building practice. In this paper, accelerated carbonation tests were performed in order to investigate carbonation process of several types of newly developed lime-based plasters. The carbonation process was monitored using the colorimetric method, whereas the gravimetric analysis was performed as well. II. CARBONATION PROCESS A. Carbonation of Lime Plaster Carbonation is a reaction of slaked lime (Ca(OH) 2 ) with carbon dioxide (CO 2 ). Within this reaction, the calcite (CaCO 3 ) is created. This reaction runs in all of lime based materials, and is accompanied by pH decrease in the carbonated areas. This is negative phenomenon in the case of concretes due to reducing of corrosive protection of embedded steel reinforcement. On the other hand, it is fundamental process for lime plasters and mortars hardening [2]. There were discovered five phases of carbonation process [3]: 1. diffusion of CO 2 gas through the porous structure of material, 2. dissolving of Ca(OH) 2 in pore solution according to the following reaction − + + → OH Ca OH Ca 2 ) ( ( 2 2 (pH>10), (1) 3. dissolving of CO 2 in pore solution − − → + 3 2 HCO OH CO , (2) 4. achievement of chemical balance of dissolved CO 2 in pore solution O H CO OH HCO 2 3 3 + → + − − − , (3) Z. Pavlík, H. Benešová, P. Matiašovský, and M. Pavlíková Study on Carbonation Process of Several Types of Advanced Lime-Based Plasters T World Academy of Science, Engineering and Technology International Journal of Materials and Metallurgical Engineering Vol:6, No:10, 2012 963 International Scholarly and Scientific Research & Innovation 6(10) 2012 scholar.waset.org/1307-6892/1834 International Science Index, Materials and Metallurgical Engineering Vol:6, No:10, 2012 waset.org/Publication/1834