Corresponding Author: Lívia Regueira Fortunato Received on 07/03/2023 Accepted on 19/04/2023 DOI: https://doi.org/10.1590/1517-7076-RMAT-2023-0078 Developing an easy-to-build laboratory chamber for CO 2 experiments Lívia Regueira Fortunato 1 , Guilherme Aris Parsekian 1 , Alex Neves Junior 2 1 Universidade Federal de São Carlos. Rod. Washington Luís, km 235, 13565-905, São Carlos, SP, Brasil. 2 Universidade Federal de Mato Grosso. Av. Fernando Corrêa da Costa, 2367, 78060-900, Cuiabá, MT, Brasil. e-mail: liviarfortunato@hotmail.com, parsekian@ufscar.br, alex.junior@ufmt.com ABSTRACT Carbonation chambers, in general, are used in civil engineering laboratories both for verifcation tests of the useful life of reinforced concrete, and for CO 2 curing tests of unreinforced cementitious materials. These chambers can be purchased from specialized manufacturers at a high cost, or they can be built by the researchers themselves. It so happens that in the literature there is no manual for making and operating an accelerated carbonation chamber. It is observed that its development and manufacture depend a lot on the needs and fnancial conditions of the research, with no standard or Technical Norm to be followed. This article presents a compilation of concepts related to the accelerated carbonation reaction and brings a bibliographical review about the diferent carbonation chambers made by researchers, in which it was possible to verify a great variation regarding the material to be used in the structure of the chamber, location of CO 2 and air inlet and outlet valves, temperature and humidity control, among others; and in addition, it presents a descriptive memorial for the construction of an automated and accessible carbonation chamber to be used in laboratories. Keywords: Chamber; accelerated carbonation; operation; descriptive plan. 1. INTRODUCTION The chemical reaction of carbonation can be analyzed on the basis of reinforced concrete structures’ durability or sustainability when it relates only to unreinforced concrete. Considering the useful life of reinforced concrete structures, carbonation can be considered harmful depending on the aggressiveness of the environment in which it is inserted. This is because it promotes a reduction in the pH of the concrete, destroying the passivator flm that involves the steel, leaving the material susceptible to corrosion [1–5]. However, in the case of unreinforced concrete, as is the case with non-reinforced cementitious precast elements (concrete blocks, units of con- crete paving, tiles, cementitious slabs etc.), the carbonation reaction is considered benefcial. The accelerated carbonation curing highly enhances the mechanical strength and permanent absorption of CO 2 from the envi- ronment [6–9]. Several studies [10–20] have used a carbonation chamber to analyze the carbonation reaction under different conditions. In one condition (to assess the useful life [durability] of reinforced concrete), the chamber is set up by considering specifc conditions like humidity, temperature, and CO 2 to accelerate the harmful efects. In the other condition, the chamber facilitates the CO 2 curing of pure concrete to assess the ideal conditions of CO 2 concentration, humidity, and temperature to maximize CO 2 absorption and enhance mechanical strength. In both cases, the chamber is essential for analyzing the efects of carbonation reactions. In many cases, these chambers are made in the laboratory by the researchers themselves without the aid of an available technical standard. Therefore, this article compiles various reactions as well as the internal and external factors that can infuence carbonation. It also conducts a review of diferent carbonation chambers. The lack of standardization can lead to varying test results and research conclusions that can signifcantly afect carbonation. In addition to this, the present article ofers a step-by-step manual for the construction of an automated and cost-efective carbonation chamber to be used in carbonation experiments.