Moisture Buffering Research Articles

Novel Approach to Making Environmentally Friendly Plaster: A Moisture Buffer Value of Plaster Made of Wastepaper and Different Glues

Novel Approach to Making Environmentally Friendly Plaster: A Moisture Buffer Value of Plaster Made of Wastepaper and Different Glues

Recycling waste tiles and waste catalysts for high-strength eco-porous ceramics in building applications

This study explores an innovative approach to recycling waste tiles and spent catalytic materials from the petrochemical industry, aiming to create ecological porous ceramics (eco-PC) as sustainable building materials. The production process involved high-pressure sintering at 5 MPa and temperatures of 900–1050 °C. Extensive testing revealed that eco-PC meets CNS 9737 standards for flexural strength, with heavy metal concentrations (measured using microwave-assisted acid digestion) within regulatory limits, confirming the materials’ recyclability. The eco-PC samples exhibited water absorption between 7.90% and 35.33%, with higher sintering temperatures reducing absorption due to vitrification, while increased waste catalyst content raised absorption due to retained porosity. Porosity ranged from 16.35% to 47.42%, influenced by sintering temperature and waste catalyst content. Loss on ignition (0.14–1.63%) was affected by the decomposition of waste catalyst and sintering temperature. Flexural strength varied from 3.36 to 179.09 N/mm2, and modulus of rupture from 458 to 16,718 N, all exceeding CNS 9737 requirements. Conversely, higher catalyst content decreased strength due to limited densification of aluminum oxide. X-ray diffraction identified quartz as the primary phase, FTIR analysis showed surface functional groups (Si–O–Si and Si–O–Al), and SEM revealed a dense structure at 1050 °C due to liquid-phase sintering. Optimal eco-PC samples with 30–40% catalyst substitution and sintering temperatures of 900–1000 °C achieved a moisture buffering value (MBV) of 3.69 g/m2·%RH@8h, ideal for humidity regulation due to high surface area and pore volume. This research demonstrates the potential to transform waste into green building resources through an efficient, cost-effective, and eco-friendly process.

Influence of bio-aggregates on the physical and hygrothermal properties of bio-concretes

The escalating demand for sustainable and energy-efficient buildings has driven research into innovative construction materials such as bio-concrete. This study assesses the influence of bio-aggregates such as bamboo particles, wood shavings, and rice husk in volume ranging from 40 % to 50 % on bio-concrete's physical and hygrothermal properties. Three bio-concrete types were fabricated: Bamboo Bio-Concrete (BBC), Wood Bio-Concrete (WBC) and Rice Husk Bio-Concrete (RHBC), while maintaining a constant cementitious matrix and varying the bio-aggregate volume. In order to characterize the bio-concretes various analyses and tests were carried out such as scanning electron microscopic (SEM) analyses and Moisture Buffer Value (MBV) tests for bio-aggregates in addition to tests for apparent density, thermal conductivity, capillary water absorption, drying index test, MBV and water vapor permeability (WVP) for the studied bio-concretes. Results reveal that despite diverse microstructural characteristics, all bio-aggregates exhibited MBV values above 3.0 [g/ (m2% RH)], highlighting their role in determining hygrothermal properties. An increase in bio-aggregate volume led to improved hygrothermal properties for bio-concretes (thermal conductivity between 0.19 and 0.25 W/m.K and MBV and WVP in the range of 2.31–3.79 [g/ (m2.% RH)] and 1.11–1.97 × 10−11 [kg/(m.s. Pa)] respectively). Bamboo bio-concrete consistently exhibited higher density values, while rice husk bio-concrete demonstrated superior moisture dynamics and water vapor permeability. Wood bio-concretes exhibit intermediate behavior between bamboo and rice husk bio-concrete. A statistical analysis confirmed these trends. The study underscores bio-concrete's potential for passive hygrothermal regulation in internal building applications, contributing to enhanced energy efficiency and sustainable construction practices.

Application and environmental sustainability assessment of microbial induced calcite precipitation in asphalt concrete crack repair

ABSTRACT Cracks are a major factor affecting the durability of asphalt concrete. Microbial-induced calcite precipitation (MICP) represents an eco-friendly method for repairing these cracks compared to conventional methods. This study investigates the repair of artificial prefabricated asphalt concrete cracks using MICP, assessing uniaxial compressive strength, permanent deformation, moisture buffering, and water sensitivity for different crack depth conditions. Microscopic analysis using SEM/EDS and X-ray micro-computed tomography was conducted. The results show that MICP reduces void fraction by 75% and increases uniaxial compressive strength and ultrasonic velocity by approximately 20%, while improving creep stiffness modulus, moisture buffering value, and resilient modulus ratio by 5%-10%. The effectiveness decreases with increasing crack depth. Calcite particles cluster within 20 mm from the crack top, enhancing mechanical properties. MICP is feasible for repairing shallow cracks. An analysis of the energy consumption and carbon emissions of the MICP technology using a life cycle assessment demonstrates that the industrial preparation processes of calcium sources and urea produce substantial carbon emissions and energy consumption, accounting for 68.31% and 94.64% of the total process, respectively, revealing that it is crucial to explore alternative materials in the future to reduce the environmental impact.

Hygrothermal characterization of cement mortar composites incorporating micronized miscanthus fibers

This work investigates both the moisture dependence of thermal properties and the hygric behavior of cement mortars incorporating different proportions of micronized miscanthus fibers up to ∼7 wt%. The experimental program encompasses thermal characterization at dry (10 % RH), moderate (50 % RH), and saturated (100 % RH) states of samples, along with hygric characterization of the various mortar specimens through sorption-desorption tests, water vapor permeability assessment, Moisture Buffer value (MBV) determination, and capillary absorption tests. Thermal measurements showed a significant decrease in thermal conductivity with the addition of fibers. For a given biobased mortar composition, conductivity values were almost identical at dry/moderate RH level but exhibited an increase at saturation. This shift was attributed to the fibers' absorptive properties, which lead to a higher water content within the samples in saturated humidity environments. Collectively, the moisture sorption, moisture buffering capacities, water vapor permeability, and capillary absorption properties demonstrated consistent enhancement with rising fiber content, confirming the significant impact of plant fibers on the material's hygrothermal properties. In addition, the GAB model (Guggenheim- Anderson- de Boer) was used to fit the sorption and desorption isotherms, yielding a good correspondence with experimental data. Finally, mortars with the higher fiber contents (M7.5 F and M10F with 5.70 wt% and 6.94 wt% of fibers, respectively) combined high hygroscopicity and low thermal conductivity values (even under moisture-saturated conditions), making them promising candidates for applications requiring both good hygric performance and effective insulation properties.

Enhancing thermo-mechanical and moisture properties of 3D-Printed concrete through recycled ultra-fine waste glass powder

This paper presents a novel approach to enhancing 3D printed concrete (3DPC) by incorporating ultra-fine glass powder (UFGP), focusing on its mechanical properties and high-temperature resistance. Investigation like fresh properties, basic physical properties, residual compressive strength after exposure to 400 °C and 800 °C, hygric properties such as water vapor diffusion resistance, liquid water transport, and moisture buffering capacity were performed the observe the effect of UFGP replacement ratio on 3DPC, which demonstrates significant improvements, highlighting the potential of UFGP to elevate 3DPCs’ performance. Results showed significant improvements, particularly with a 20% UFGP mix, which showed the lowest compressive strength loss (9.0% at 400 °C and 53.7% at 800 °C). Additionally, the water vapor diffusion resistance factor for the 20% UFGP mix was measured at 65.03. These results suggest that incorporating UFGP in 3DPC enhances thermal resilience and mechanical properties, offering a solution for high-temperature construction. This study contributes to sustainable construction by emphasizing the importance of mechanical resilience for structural integrity under extreme temperatures.

Can mussel shell waste optimize cement and air lime mortars hygrothermal performance?

Mussel shells used as aggregates for mortars have flaky and irregular particles, which significantly increases the pore volume. This leads to the identification the microstructure of mussel shell mortars as a light and porous composite, which could have good hygrothermal properties. In the present study, the density and thermal properties are assessed on cement and air lime mortars, each with three replacement percentages of replacement of conventional sand by mussel shell sand (25 %, 50 % and 75 %), are evaluated and compared with their respective baselines (0 % replacement). Thermal conductivity measurements are also carried out on different loose fractions of the mussel shell aggregate to understand the behaviour of this material without binder matrix. Finally, adsorption and desorption cycles at 80 % and 50 % relative humidity are carried out on loose aggregate fractions and on the eight mortars. The results are very positive for the mussel shell mortars, as it can be concluded that the use of mussel shell aggregates improves the thermal performance and the potential moisture buffering capacity of both cement and air-lime coating mortars.

Preparation and properties of a rigid hemp shiv insulation particle board using citric acid-glycerol mixture as an eco-friendly binder

Particle boards are commonly manufactured from wood-based material bound with a thermosetting adhesive based on the reaction of formaldehyde with phenol, urea, melamine, or co-condensates. The use of formaldehyde is a cause for concern due to its harmful emissions. This study investigates the use of an alternative binder combined with particles derived from a short-cycle crop as an alternative to timber derived particles. A low density particle board was developed using hemp shiv as an aggregate with a binder made with crude glycerol, derived from the waste stream of the bio-diesel industry, esterified with citric acid under heat activation. This board was characterized and found to have good mechanical properties, low thermal conductivity, and good moisture buffering. Dimensional stability was compromised by swelling when exposed to water, but it will be possible to address this shortcoming using hydrophobic additives. The acoustic properties of the board were also found to be excellent, showing potential for use as a thermally insulating acoustic separator for internal walls.

Hygrothermal and mechanical characterization of novel hemp-lime composites with enhanced consistency

Hemp-lime composites have captured attention in the construction industry due to their sustainability and excellent hygrothermal performance. However, variability and inconsistent performance have hindered their widespread adoption. This research introduces a novel approach to improve the uniformity and hygrothermal characteristics, aiming for reproducibility and consistency comparable to traditional insulation materials. This method included (1) reducing hemp particle size to coarse (1.33 mm), medium (0.92 mm), and fine (0.72 mm) particles; (2) maximizing the hemp proportion to 70 % by weight; and (3) standardizing dry density using vibration techniques. The findings indicate dry density variability reduction in all samples, with a coefficient of variation ranging from 0.16 % to 2.36 %. The hygrothermal analysis demonstrates enhanced insulation and moisture-buffering properties, along with reduced directional disparity in thermal conductivity (1.2–6.8 %) compared to the control sample, particularly in samples with fine particle sizes. Thermal conductivity was within the range of 0.0535–0.0667 W/m K, considerably lower than previously reported values. Also, a positive correlation is observed between moisture-buffering and hemp ratio, indicating that higher hemp ratios in the composite lead to increased moisture capacity, with moisture buffer values of 2.47, 2.28, and 2.12 g/m² RH corresponding to the binder-to-hemp ratio of 30:70, 40:60, and 50:50 by weight, respectively.

Assessing the impact of moisture buffering properties of materials on indoor environmental quality: A study on a recycled material plaster

This study examines Moisture Buffer Value (MBV) of interior finishing layers, which impacts buildings internal relative humidity, thus indoor environmental quality. The MBV depends on material's moisture capacity and vapour diffusion resistance factor, both of which depends on relative humidity. The paper aims to (i) characterize a new recycled material plaster that includes construction and food industry waste through laboratory measurements, (ii) use dynamical building simulations to quantify the impact of the MBV of existing and the new interior plaster on relative humidity in real design scenarios, and (iii) evaluate how changing the definition of the MBV to consider its dependence on indoor air relative humidity can improve its accuracy. Results show that the plaster's moisture buffering properties significantly reduce the variations of the relative humidity of interior climates compared to a vapour-tight finishing layer. The performances of the new plaster made with recycled materials are comparable to those of the other plasters. The new MBV definitions (“Dynamical MBV″ and “Summer/Winter MBV”) show a significantly improved correlation with the relative humidity variations of indoor climates of buildings, observed in dynamic simulations, with respect to the typically used practical MBV. The new definitions are therefore promising for practical applications.

Characterization and optimization of desulfurized construction gypsum modified with functionalized nanocellulose

This study focuses on the development and characterization of a novel composite material based on flue gas desulfurization (FGD) gypsum modified with functionalized nanocellulose. The incorporation of 0.1 wt% nanocellulose into the FGD gypsum matrix resulted in significant improvements in mechanical strength, water resistance, and thermal insulation properties. The flexural and compressive strength of the optimized composite increased by 32 % and 27 %, respectively, compared to the control sample. The water absorption decreased by 22 %, and the softening coefficient increased from 0.72 to 0.85, indicating enhanced water resistance. The thermal conductivity of the composite was reduced by 31 %, showcasing its potential as an energy-efficient building material. SEM analysis revealed a refined microstructure with improved interfacial bonding between the nanocellulose and gypsum matrix, while FTIR spectroscopy confirmed the presence of chemical interactions between the components. The moisture buffering capacity of the composite was also superior, with a 38 % higher moisture buffering value than the control sample. These findings highlight the potential of functionalized nanocellulose as a reinforcing agent in FGD gypsum-based composites, offering a promising solution for the development of high-performance, eco-friendly building materials.

Influence of materials and surface parameters on the moisture buffering in office buildings: A sensitivity analysis of China

The management of indoor humidity through equipment consumes massive energy, leading to the growing interest in passive regulation of indoor humidity via moisture buffering. Numerous factors may impact the performance of interior finishing material during moisture regulation, thus identifying the dominant parameters is critical for moisture buffering effect optimization. This study analyzes the influence of five moisture and surface parameters, which are directly related to the moisture transfer of the interior finishing layer, on the thermal loads in a typical office building under typical climates in China. The analysis employs scatter plots and sensitivity indices based on Sobol's method. The results show that the material thickness plays a decisive role under different climates. The importance of sorption isotherm varies with climates and load types. The vapor diffusion resistance factor of the material only affects the latent heat loads, while the effect of the surface vapor transfer resistance is negligible. Finally, this study puts forward suggestions for interior finishing material selection to achieve low-load performance based on the characteristics of parameter combinations.

3D-printed clay components with high surface area for passive indoor moisture buffering

This study focuses on implementing a novel approach in which clay 3D-printed matrices were designed as a passive comfort solution to enhance indoor moisture buffering and air quality. Liquid Deposition Modeling additive manufacturing and parametric design were implemented to develop the components, which were characterized for having an increased specific surface exposed to air and moisture per volume unit, which showed to significantly enhance moisture buffering. This revealed a clear linear relationship between the two parameters. Additionally, the components showed a significant increase in the practical Moisture Buffering Value (MBV) and mass reduction compared to a solid clay reference. Furthermore, this research analyzed the influence of two stabilization techniques on the moisture uptake capacity of the samples, i.e. thermal treatment at different temperatures between 600 and 1000 °C and mixing with calcium hydroxide paste within the 10–40 % range. Finally, the morphological (scanning electron microscopy) and crystallographic (X-ray diffraction) analyses of the samples show a correlation between microstructural modifications and the variations of moisture uptake capacity and MBV. In addition, nitrogen adsorption-desorption measurements revealed that sample porosity decreased as the temperature of the thermal treatment increased, showing a correlation with the decrease of practical MBV.

Moisture buffer value for hygroscopic materials with different thicknesses

Moisture buffer value (MBV) is a critical parameter for assessing hygroscopic material's ability to moderate indoor humidity variation. The original MBV theory is strictly valid only for a semi-infinite (or “very thick”) material. When the material is thinner than semi-infinite, the material's thickness will affect its moisture buffering ability. The existing MBV theory is inapplicable. This study proposed a new numerical method to calculate a material's MBV at different thicknesses. The proposed model is simple and efficient. The relation between a material's MBV and thickness and the optimal thickness can be obtained without extensive experimental measurement. What's more, the material's adsorption and desorption isotherms, as well as the material's hysteresis loop and scanning isotherms, are incorporated in the proposed model, making it applicable to advanced desiccant materials like Metal-Organic Frameworks (MOFs). MIL-100(Fe), one of the most promising MOF candidates for indoor humidity control, was used to validate the newly developed model. MBVs of MIL-100(Fe) samples with different thicknesses were measured, and the experimental data closely matched the simulated results. Finally, a building energy consumption simulation model was developed based on the proposed numerical model. A MOF panel with its optimal thickness was placed in the BESTEST typical office room located in Copenhagen. The results show that MOF can reduce about 30 % of the energy consumption of air conditioning in a purely passive way.

Experimental study on thermal and humidity properties of modified rammed earth buildings in winter

Rammed earth materials have been used in traditional buildings for thousands of years. Currently, with the interest in environmentally friendly societies, rammed earth construction has regained attention owing to its characteristics of energy conservation, environmental protection, low cost, and local material extraction. In this study, cement, gravel, sand, and polypropylene fibers were used as the modifying materials of rammed earth. The thermal and humidity physical parameters are measured at different moisture contents after modification, and the isothermal hygroscopic curves are fitted. The experimental findings demonstrated positive correlations between the specific heat capacity and thermal conductivity and the moisture content. The temperature and humidity of a modified rammed earth test building were recorded for seven days during winter. The test findings revealed that, throughout the test, the moisture content in the middle of the wall was consistently higher than that in the inner surface. When the outdoor temperature fluctuation was 14.95 °C, the inner surface temperature and indoor temperature fluctuation were 2.73 °C and 3.08 °C, respectively. Moreover, the inner surface temperature of the wall became maximum 7–8 h after the maximum outer surface temperature is reached, on average. The above data show that a modified rammed earth wall has exceptional heat and moisture storage capacities as well as heat and moisture buffering characteristics, which can reduce fluctuations in indoor temperature and humidity and create a more comfortable indoor living environment.

Hygrothermal Properties and Performance of Bio-Based Insulation Materials Locally Sourced in Sweden.

In recent years, there has been a paradigm shift in the building sector towards more sustainable, resource efficient, and renewable materials. Bio-based insulation derived from renewable resources, such as plant or animal fibres, is one promising group of such materials. Compared to mineral wool and polystyrene-based insulation materials, these bio-based insulation materials generally have a slightly higher thermal conductivity, and they are significantly more hygroscopic, two factors that need to be considered when using these bio-based insulation materials. This study assesses the hygrothermal properties of three bio-based insulation materials: eelgrass, grass, and wood fibre. All three have the potential to be locally sourced in Sweden. Mineral wool (stone wool) was used as a reference material. Hygrothermal material properties were measured with dynamic vapour sorption (DVS), transient plane source (TPS), and sorption calorimetry. Moisture buffering of the insulation materials was assessed, and their thermal insulation capacity was tested on a building component level in a hot box that exposed the materials to a steady-state climate, simulating in-use conditions in, e.g., an external wall. The tested bio-based insulation materials have significantly different sorption properties to stone wool and have higher thermal conductivity than what the manufacturers declared. The hot-box experiments showed that the insulating capacity of the bio-based insulators cannot be reliably calculated from the measured thermal conductivity alone. The results of this study could be used as input data for numerical simulations and analyses of the thermal and hygroscopic behaviour of these bio-based insulation materials.

Preparation and Performance of Inorganic Hydrated Salt-Based Composite Materials for Temperature and Humidity Regulation

In this work, it was first proposed to combine hydrated salt phase change materials (PCMs) with humidity control materials to prepare the temperature and humidity control material. The composite PCM was prepared by absorbing Na2HPO4·12H2O with colloidal silicon dioxide, and diatomite was selected as the humidity control material. The humidity performance tests found that diatomite had good moisture absorption/desorption capacity and excellent moisture buffering capacity. The supercooling degree tests showed that Na2SiO3·9H2O as nucleating agent effectively reduced the supercooling degree, and the addition of deionized water improved the water loss problem of composite PCMs. The DSC tests showed that the enthalpy and melting temperature of composite PCMs were 153.1 J/g and 28.9°C, respectively. By placing the temperature and humidity control material in different humidity, it was found that the moisture content of diatomite affected the thermal properties of composite PCMs. Diatomite could not only transfer moisture to hydrated salts but also absorb moisture from hydrated salt. The application performance tests of the temperature and humidity control material in the room model showed that it could simultaneously regulate indoor temperature and humidity. Overall, this temperature and humidity control material was more suitable for environments with high relative humidity such as greenhouses.

Bio-based innovations in cross-laminated timber (CLT) envelopes: A hygrothermal and life cycle analysis (LCA) study

The purpose of this study is to evaluate the performance of a Cross-Laminated Timber (CLT) building envelope that employs more bio-based materials, in terms of its hygrothermal behavior and environmental impact. The study involved the construction of four wall assemblies, comparing the effects of the installation of a self-adhesive air barrier on the CLT and the choice of insulation: bio-based wood fiber insulation or stone wool insulation. The walls were subjected to static and dynamic tests in a climate chamber, with temperature and relative humidity sensors installed across the walls. Additionally, the life cycle analysis (LCA) of the identical assemblies was calculated using the Ecoinvent 3.5 database.The findings of the study showed that the wood fiber insulation had a lower relative humidity and a temperature similar to the stone wool insulation. The air barrier reduced the transfer of moisture and increased the temperature across the wall. Furthermore, the wood fiber insulation acted as a moisture buffer, thereby delaying the migration of moisture through the envelope. Concerning the LCA, the metal siding had the highest global warming impact, followed by the insulation types. The wood fiber insulation had a similar impact to the stone wool insulation, except for eutrophication, where stone wool had a lower impact. The air barrier had a negligible impact compared to the rest of the envelope but prevented the CLT wall from being fully recycled. The biogenic carbon stored in the CLT and the wood fiber insulation reduced the global warming potential of the walls.

Mechanical and hygrothermal properties of hemp-silica bio-composites

This research investigated the development of a fast-drying silica-based binder for hemp concrete products with enhanced mechanical and thermal properties. Hemp-silica bio-composites were prepared by mixing hemp shivs with a two-component binder system composed of liquid sodium silicate and tributyl citrate (TBC). Compressive strength, thermal conductivity, moisture buffering value, cyclic moisture resistance and microstructure of hemp-silica composites were analysed, and the results were compared with those of hemp-lime concrete. Hemp-silica blocks with shiv-liquid sodium silicate mass ratio of 1:3.75 and TBC content of 37.5 wt% of sodium silicate dry matter produced a compressive strength of 0.56 MPa only after 3 days of drying and 1.92 MPa after 28 days. These were higher than hemp-lime blocks at the same density range. Hemp-silica panels showed a thermal conductivity of 0.101 W/mK and an excellent moisture buffering value of 3.49. Hemp silica formed an open porosity with large air gaps between the particles and a water-resistance silica-based layer on the shiv surface producing a higher moisture resistance compared to hemp-lime systems. This paper focuses on the development of a novel fast-drying binder system with a potential for use in conjunction with other lingnocellular plant aggregates to form low-carbon and efficient multifunctional building materials.

Effect of Na/Al and curing moisture conditions on sodium aluminosilicate hydrate (N–A–S–H) geopolymers’ hydric properties

Anthropogenic climate change is one of the main reasons for mainstreaming sustainability in all sectors. Reducing the carbon footprint of the built environment is one of the sustainability goals which is universally accepted. Reducing the carbon emissions from buildings entails cutting back operational and embodied carbon. Geopolymers are one of these materials that have been under focus recently for their capacity to reduce these two sources’ emissions in buildings. In this study, the authors added to their previous work on understanding aerated geopolymers’ performance as building materials. This article presents the effect of Na/Al ratio and curing moisture on the moisture storage, transfer, and moisture buffering capacity (MBC) of aerated geopolymers. The impact of vapor gradient and exposure to variable environmental conditions (temperature and relative humidity(%RH)) are also surveyed. Generally, the results show correlations between hydric performance and the tested experimental parameters. This stems from the influence of Na/Al and curing relative humidity on the degree of geopolymerization, rate of reaction, porosity, and phase composition of metakaolin-based geopolymers. Vapor permeability and moisture diffusivity increased with rising alkali oxide content because of the higher degree decomposition of porogen and pore stabilization effect of rapid polycondensation. Moisture permeability and diffusivity also showed direct relationships with curing relative humidity. Low relative humidity results in the rapid loss of inter-layer water and leads to densification of the matrix, while high %RH curing is suitable for pore formation and stability. The MBC of the samples increases with increasing Na/Al because of increased porosity leading to access to more gel pores. However, at high values, the sub-carbonation (internal carbonation) and carbonation lead to the formation of sodium carbonate, which is highly hydrophilic and influences the material's moisture exchange capacity negatively. This justifies the lower MBC at Na/Al=1. A similar observation was made when curing moisture content was increased. The influence of the Na/Al and curing moisture on the pore statistics of the geopolymer matrix are observed by their adsorption isotherms. At lower curing humidity and Na/Al, the samples tend to be less macroporous, dominated mainly by micropores. This is evidenced by the onset of capillary condensation at low %RH because of raid pore filling. The results also demonstrate the critical role Na/Al plays in determining the resulting matrix’s microstructural integrity. This is evidenced by the low durability of the sample with Na/Al equal to 1.2. The samples’ loss of structural integrity is because of carbonation-triggered retardation of strength development and stress put on micropores because of sub-carbonation-driven crystallization.