When visiting underground spaces that have poor ventilation or building that are surrounded by cement concrete, we can detect a pungent odor as the unique smell of concrete. This odor is caused by the various gases occurring by the hydration process of cement concrete (or mortar), while the amount a...
When visiting underground spaces that have poor ventilation or building that are surrounded by cement concrete, we can detect a pungent odor as the unique smell of concrete. This odor is caused by the various gases occurring by the hydration process of cement concrete (or mortar), while the amount and types of gas depend on the composite materials and environmental factors such as moisture, temperature etc. And gases from hydration process of cement concrete(mortar) can be released through fast diffusion in concrete and have a significant influence on men’s health and air pollution, and they are becoming a serious problem throughout the world. However, only a few investigations on hydration gas released from cement concrete have been carried out. The focus of this paper is to make the measuring process the emission of hydration gases from cement concrete, analysis of occurrence mechanism and laboratory animal exposure risk assesment of cement concrete. In this study, first, the capture and analysis processor of gas were configured using Air Pollution Process Test Method and Indoor Air Quality Test Method to conduct the qualitative and quantitative analysis of gas which occurs in the concrete. And the following experiments were progressed: 1) This paper is to measure the emission of NH3 from cement mortar using different aggregate according to the area of production and to investigate the relationship between the amount of organic matter and ammonium(NH4+) contained in the aggregate as well as the emission of NH3 from cement mortar using different aggregate from area of production. 2) To evaluate the pattern of gases emission from cement concrete mixed with additives, the emission levels of gas including ammonia (NH3), volatile organic compounds(VOCs), Radon were measured from 3 different mortar types(Ordinary Portland Cement, Ordinary Portland Cement with fly ash, Ordinary Portland Cement with GBFS) on various time points after manufacture. 3) In order to determine what the VOCs and ammonia gas from concrete the potential have an effect in the progression of Asthma disease, the Asthma was induced to mice using OVA model. The mice were allowed to live within a concrete cage after this, and it was identified what a physiological changes were occuring for them. 4) To examine their effects on allergic respiratory system, mice were sensitized with ovalbumin(OVA) and divided five groups(normal, asthma control, OPC mortar, OPC mortar with fly ash and OPC mortar with GBFS). And mice were housed in each cage for 10 days with OVA challenges to induce asthma. Results are as follows 1) In the case of ammonia gas which occurs in the concrete, the Indophenol method using the solution absorption method was applied, and in the case of VOCs, the analysis processor was organized using Purge & Trap GC/MS method. 2) It is found that NH3 released from cement mortars is produced by the reaction of NH4+ adsorbed into the aggregate with a strong alkali in cement mortar, as a process of ammonia volatilization. The concentrations of NH3 emission from cement mortar according to the aggregate used from different areas of production differ by more than 4 times. And the differences depend on the content of NH4+ adsorbed into the aggregate. The results of the experiment indicate that the content of ammonium ion in sand is strongly related to the content of organic matter. This is because ammonium ion is composed of organic matter and the increase of organic matter leads to the increase of ammonium ion due to the high CEC of the aggregate. 3) As the mixing ratio of GBFS and Fly ash was increased, the ammonia emission of concrete was increased. In the case of Fly ash concrete, the ammonia adsorbed on the surface of Fly ash in SCR treatment process for nitrogen control was identified as a source of gas. In the case of GBFS, the atmospheric nitrogen dissolved in the form of freedom nitrogen in the manufacturing process of the molten slag in high temperature state, and the magnesium mixed into the slag were the causes. 4) A trace of VOCs was analyzed in OPC mortar, Fly ash mortar, GBFS mortar and especially, Fly ash mortar were occurred the emission of the most diverse types of VOCs in the early material age. In addition, in the case of the admixture, various VOCs was analyzed depending on the type of synthesis. 5) Histopathologically, increased infiltration of lymphocytes was observed in perivascular area of lung of mice housed in both OPC mortar and OPC mortar with fly ash cages compared to asthma control. Moreover, severe bronchial lumen obstruction and increased hypertrophy of bronchial epithelial cells (p<0.05) were observed in OPC mortar with fly ash group compared to OPC mortar or asthma control groups. Lungs of two mortar groups (OPC, OPC with fly ash) generally expressed higher levels of genes related with asthma including IL-4, eotaxin and EGF compared to asthma control mice. Additionally, OPC mortar with fly ash group showed higher expression of IL-5, 13 and MCP-1 compared to asthma control group. These results indicate that OPC mortar and fly ash might contribute to exacerbate asthma.
When visiting underground spaces that have poor ventilation or building that are surrounded by cement concrete, we can detect a pungent odor as the unique smell of concrete. This odor is caused by the various gases occurring by the hydration process of cement concrete (or mortar), while the amount and types of gas depend on the composite materials and environmental factors such as moisture, temperature etc. And gases from hydration process of cement concrete(mortar) can be released through fast diffusion in concrete and have a significant influence on men’s health and air pollution, and they are becoming a serious problem throughout the world. However, only a few investigations on hydration gas released from cement concrete have been carried out. The focus of this paper is to make the measuring process the emission of hydration gases from cement concrete, analysis of occurrence mechanism and laboratory animal exposure risk assesment of cement concrete. In this study, first, the capture and analysis processor of gas were configured using Air Pollution Process Test Method and Indoor Air Quality Test Method to conduct the qualitative and quantitative analysis of gas which occurs in the concrete. And the following experiments were progressed: 1) This paper is to measure the emission of NH3 from cement mortar using different aggregate according to the area of production and to investigate the relationship between the amount of organic matter and ammonium(NH4+) contained in the aggregate as well as the emission of NH3 from cement mortar using different aggregate from area of production. 2) To evaluate the pattern of gases emission from cement concrete mixed with additives, the emission levels of gas including ammonia (NH3), volatile organic compounds(VOCs), Radon were measured from 3 different mortar types(Ordinary Portland Cement, Ordinary Portland Cement with fly ash, Ordinary Portland Cement with GBFS) on various time points after manufacture. 3) In order to determine what the VOCs and ammonia gas from concrete the potential have an effect in the progression of Asthma disease, the Asthma was induced to mice using OVA model. The mice were allowed to live within a concrete cage after this, and it was identified what a physiological changes were occuring for them. 4) To examine their effects on allergic respiratory system, mice were sensitized with ovalbumin(OVA) and divided five groups(normal, asthma control, OPC mortar, OPC mortar with fly ash and OPC mortar with GBFS). And mice were housed in each cage for 10 days with OVA challenges to induce asthma. Results are as follows 1) In the case of ammonia gas which occurs in the concrete, the Indophenol method using the solution absorption method was applied, and in the case of VOCs, the analysis processor was organized using Purge & Trap GC/MS method. 2) It is found that NH3 released from cement mortars is produced by the reaction of NH4+ adsorbed into the aggregate with a strong alkali in cement mortar, as a process of ammonia volatilization. The concentrations of NH3 emission from cement mortar according to the aggregate used from different areas of production differ by more than 4 times. And the differences depend on the content of NH4+ adsorbed into the aggregate. The results of the experiment indicate that the content of ammonium ion in sand is strongly related to the content of organic matter. This is because ammonium ion is composed of organic matter and the increase of organic matter leads to the increase of ammonium ion due to the high CEC of the aggregate. 3) As the mixing ratio of GBFS and Fly ash was increased, the ammonia emission of concrete was increased. In the case of Fly ash concrete, the ammonia adsorbed on the surface of Fly ash in SCR treatment process for nitrogen control was identified as a source of gas. In the case of GBFS, the atmospheric nitrogen dissolved in the form of freedom nitrogen in the manufacturing process of the molten slag in high temperature state, and the magnesium mixed into the slag were the causes. 4) A trace of VOCs was analyzed in OPC mortar, Fly ash mortar, GBFS mortar and especially, Fly ash mortar were occurred the emission of the most diverse types of VOCs in the early material age. In addition, in the case of the admixture, various VOCs was analyzed depending on the type of synthesis. 5) Histopathologically, increased infiltration of lymphocytes was observed in perivascular area of lung of mice housed in both OPC mortar and OPC mortar with fly ash cages compared to asthma control. Moreover, severe bronchial lumen obstruction and increased hypertrophy of bronchial epithelial cells (p<0.05) were observed in OPC mortar with fly ash group compared to OPC mortar or asthma control groups. Lungs of two mortar groups (OPC, OPC with fly ash) generally expressed higher levels of genes related with asthma including IL-4, eotaxin and EGF compared to asthma control mice. Additionally, OPC mortar with fly ash group showed higher expression of IL-5, 13 and MCP-1 compared to asthma control group. These results indicate that OPC mortar and fly ash might contribute to exacerbate asthma.
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