Supporting information Hydration Mechanism of the Hydrogen-rich ...
Supporting information Hydration Mechanism of the Hydrogen-rich Water Based Cement Paste Sumit Chakraborty1, Byung wan Jo1*, Muhammad Ali Sikandar1 1
Department Civil and Environmental Engineering, Hanyang University, Seoul, South Korea, 133791 1
*Corresponding author’s address: email: [email protected]; [email protected]; Phone: +82-2-2220-1804; Fax: +82-2-2292-0321 Advantages and disadvantages of the existing cement set accelerator and the hydrogen-rich water The set accelerator is used to speed up the pace of construction by reducing the induction time1, 2. In fact, the set accelerators are used to increase the production rate of the concrete, reduce the damaging risk of the concrete structures at the early age, and repair the structure very quickly. The best-known accelerator is calcium chloride1-3. Additionally, some other accelerators such as nitrate, nitrite, formate, thiosulfate, and thiocyanate salts are preferred in formulations for precast concretes. However, these are less efficient as compared to that of the calcium chloride1-3. The use of these chemical admixtures leads to release some toxic gasses such as volatile formaldehyde and nitrogen dioxide, etc., which are responsible for the several environmental problems such as air pollution water pollution, etc4. On the other hand, there are several restrictions on the use of calcium chloride as a set accelerator admixture1-3. Therefore, the development of an alternative non-chloride and the non-toxic set accelerator is sought around the world. In this study, the hydrogen-rich water is used as cement set accelerator. Table S1 summarizes the advantage and disadvantages of the use of calcium chloride and hydrogen-rich water. Additionally, an approximate cost analysis for the use of hydrogen-rich water as a cement set accelerator in producing the concrete is depicted in Table S2. S1
Table S1. Advantages and disadvantages of the calcium chloride and the hydrogen-rich water used as a cement set accelerator Features Setting time
Calcium chloride Minimizes the setting time1-3.
Hydration
1. Increase the rate of cement hydration. 2. Minimizes the induction period. 3. Increases the heat of hydration. 4. Increases the rate coagulation and flocculation of the hydrated product. 5. Increases the amount of hydrated product1-3. Minimizes curing period to achieve target strength1. Decreases the porosity1-3. Increases the early age mechanical strength1-3. The pH of the interstitial solution decreases1, 3. Concrete will be chloride rich1-3.
Curing Porosity Mechanical strength pH Chloride enrichment Corrosion Freeze-thaw durability Restriction for use
Dose and addition
Mode of action
Influences the corrosion of reinforced steel1-3, 6 At the early age, durability is high, however, later age durability decreases1. It could not use to produce prestressed concrete, potentially reactive aggregate based concrete, nuclear power plant, concrete exposed to seawater, and in the hot climate3. 2% w.r.t weight of cement (acceptable1-3. It should be added at the plant site for preparing the ready mix concrete1. Its operational mode is not entirely understood. There still exists some controversies among researchers4.
Hydrogen-rich water Minimizes the setting time significantly5. Hydration behavior is observed to be similar to the calcium chloride (present research).
Similar to the calcium chloride. Decreases the porosity5. Increases the early age mechanical strength5. No decrease in pH takes place. No such chloride enrichment. No such possibility of corrosion (future research) Unknown (Future aspect of the research No such restriction for its use. It could be used to prepare all types of concrete. Additionally, it can be applied in hot and cold weather as well. 0.5 ppm hydrogen-rich water is acceptable for the fabrication of concrete5. Its addition should be similar to the calcium chloride. The present paper contributes to increasing the understanding of the mechanism (action) of the cement set accelerator and the H2rich water
S2
Cost analysis In this study, the extra cost required to produce 1 cubic meter concrete using hydrogen-rich water and calcium chloride has been calculated. Prior to analyzing the cost, an M-35 grade concrete is selected in which the cement consumption is 360 kg/m3 and the water-cement ratio is 0.57. The total consumed water is calculated to be 180 liters. It is reported elsewhere that the 2% calcium chloride w.r.t. the weight of cement is a standard amount for the production of the conventional set accelerated concrete1-3. Hence, it is estimated that the total consumed calcium chloride is 7.2 kg. Additionally, from the experiment, it is observed that for the production of 1 liter 0.5 ppm hydrogen-rich water, 0.36 g of the metal hydride mixture (a mixture of magnesium hydride and silicon hydride) is consumed. Hence, to produce 180 liters 0.5 ppm hydrogen-rich water, 64.8 g of the metal hydride mixture will be consumed. The extra cost required to produce 1 cubic meter concrete using calcium chloride and hydrogen-rich water is calculated as follows: Table S2. The extra cost required to produce 1 cubic meter concrete using calcium chloride and hydrogen-rich water (consumed cement and water are 360 kg and 180 liters, respectively) Type of concrete
Dose of calcium chloride 2% w.r.t. weight of cement4-6
Dose of hydrogenrich water --
Total amount of calcium chloride (kg) 7.2
Total amount of metal hydride (g) --
Cost/ container (USD) 10.95/ 500 g containera
Total cost (USD) 157.68b
Calcium chloride based concrete Hydrogen- -0.5 ppm -64.8 12.5 / 20 g 40.5d c rich water (present container based study) concrete a Cost of calcium chloride per 500 g container reported in http://www.sciencecompany.com/Calcium-Chloride-Lab-Grade-500g-P6381.aspx, bExtra cost needed for the fabrication of 1 cubic meter calcium chloride based concrete, ccost of the metal hydride mixture per 20 g container reported in www.h2vision.co.kr, dExtra cost needed for the fabrication of 1 cubic meter hydrogen-rich water based concrete.
S3
Figure S1. The particle size distribution curve of the ordinary Portland cement used in this investigation Table S3. Chemical composition of the ordinary Portland cement used in this investigation Cement Ordinary Portland cement *Loss of ignition
SiO2 20.36
Al2O3 5.77
Chemical compositions (%) Fe2O3 CaO MgO Na2O 2.84 64.33 2.05 0.00
LI* 2.00
S4
Figure S2. Variation of the hydrogen-rich water concentration with the increase in time (min).
S5
Figure S3. The typical fitting and deconvolution of the XRD pattern of 1, 3, 7, and 28 days hydrated control cement (0CC) and 0.5 ppm hydrogen-rich water based cement (0.5HC) sample, (A) 0CC-1day, (B) 0CC-3days, (C) 0CC-7days, (D) 0CC-28days, (E) 0.5HC-1day, (F) 0.5HC3days, (G) 0.5HC-7days, and (H) 0.5HC-28days. S6
Figure S4. TG-DTG plot of the 7, 14 and 28 days hydrated control (0CC) and 0.5 ppm hydrogen-rich water based cement sample (0.5HC).
S7
References (1) Ramachandran, V. S. Concrete admixtures handbook properties, science and technology 2nd Edn.; Ramachandran, V. S., Ed.; Noyes Publications, New Jersey, USA, 1995. (2) Rixom, R.; Mailvaganam, N. Chemical admixtures for concrete 3rd Edn.; Rixom, R.; Mailvaganam, N., Eds.; E & FN Spon, 11 New Fetter Lane, London, 1999. (3) Aïtcin, P. C.; Flatt, R. J. Science and technology of concrete admixtures 1st Edn.; Aïtcin, P. C.; Flatt, R. J., Eds.; Woodhead publishing, Cambridge, UK, 2015. (4) Bower, J. The healthy house 4th Edn.; Bower, J., Ed.; The Healthy House Institute, Bloomington, IN, 2001. (5) Jo, B. W.; Chakraborty, S.; Sikandar, M. A.; Kim, H.; Kim, K. H. Hydrogen-rich water revealed benefits in controlling the physical and mechanical performances of cement mortar. Constr. Build. Mater. 2015, 100, 31–39. (6) Building code requirements for structural concrete (ACI 318-08) and commentary; ACI 318-2008; An ACI Standard; American Concrete Institute, Farmington Hills, MI 48331, USA, 2008. www.concrete.org. (7) Guidelines for concrete mix design proportioning [CED 2: Cement and concrete]; IS 10262-2009; Bureau of Indian Standards: New Delhi, India, 2009.
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Department Civil and Environmental Engineering, Hanyang University, Seoul, South Korea, 133791 1
*Corresponding author’s address: email: [email protected]; [email protected]; Phone: +82-2-2220-1804; Fax: +82-2-2292-0321 Advantages and disadvantages of the existing cement set accelerator and the hydrogen-rich water The set accelerator is used to speed up the pace of construction by reducing the induction time1, 2. In fact, the set accelerators are used to increase the production rate of the concrete, reduce the damaging risk of the concrete structures at the early age, and repair the structure very quickly. The best-known accelerator is calcium chloride1-3. Additionally, some other accelerators such as nitrate, nitrite, formate, thiosulfate, and thiocyanate salts are preferred in formulations for precast concretes. However, these are less efficient as compared to that of the calcium chloride1-3. The use of these chemical admixtures leads to release some toxic gasses such as volatile formaldehyde and nitrogen dioxide, etc., which are responsible for the several environmental problems such as air pollution water pollution, etc4. On the other hand, there are several restrictions on the use of calcium chloride as a set accelerator admixture1-3. Therefore, the development of an alternative non-chloride and the non-toxic set accelerator is sought around the world. In this study, the hydrogen-rich water is used as cement set accelerator. Table S1 summarizes the advantage and disadvantages of the use of calcium chloride and hydrogen-rich water. Additionally, an approximate cost analysis for the use of hydrogen-rich water as a cement set accelerator in producing the concrete is depicted in Table S2. S1
Table S1. Advantages and disadvantages of the calcium chloride and the hydrogen-rich water used as a cement set accelerator Features Setting time
Calcium chloride Minimizes the setting time1-3.
Hydration
1. Increase the rate of cement hydration. 2. Minimizes the induction period. 3. Increases the heat of hydration. 4. Increases the rate coagulation and flocculation of the hydrated product. 5. Increases the amount of hydrated product1-3. Minimizes curing period to achieve target strength1. Decreases the porosity1-3. Increases the early age mechanical strength1-3. The pH of the interstitial solution decreases1, 3. Concrete will be chloride rich1-3.
Curing Porosity Mechanical strength pH Chloride enrichment Corrosion Freeze-thaw durability Restriction for use
Dose and addition
Mode of action
Influences the corrosion of reinforced steel1-3, 6 At the early age, durability is high, however, later age durability decreases1. It could not use to produce prestressed concrete, potentially reactive aggregate based concrete, nuclear power plant, concrete exposed to seawater, and in the hot climate3. 2% w.r.t weight of cement (acceptable1-3. It should be added at the plant site for preparing the ready mix concrete1. Its operational mode is not entirely understood. There still exists some controversies among researchers4.
Hydrogen-rich water Minimizes the setting time significantly5. Hydration behavior is observed to be similar to the calcium chloride (present research).
Similar to the calcium chloride. Decreases the porosity5. Increases the early age mechanical strength5. No decrease in pH takes place. No such chloride enrichment. No such possibility of corrosion (future research) Unknown (Future aspect of the research No such restriction for its use. It could be used to prepare all types of concrete. Additionally, it can be applied in hot and cold weather as well. 0.5 ppm hydrogen-rich water is acceptable for the fabrication of concrete5. Its addition should be similar to the calcium chloride. The present paper contributes to increasing the understanding of the mechanism (action) of the cement set accelerator and the H2rich water
S2
Cost analysis In this study, the extra cost required to produce 1 cubic meter concrete using hydrogen-rich water and calcium chloride has been calculated. Prior to analyzing the cost, an M-35 grade concrete is selected in which the cement consumption is 360 kg/m3 and the water-cement ratio is 0.57. The total consumed water is calculated to be 180 liters. It is reported elsewhere that the 2% calcium chloride w.r.t. the weight of cement is a standard amount for the production of the conventional set accelerated concrete1-3. Hence, it is estimated that the total consumed calcium chloride is 7.2 kg. Additionally, from the experiment, it is observed that for the production of 1 liter 0.5 ppm hydrogen-rich water, 0.36 g of the metal hydride mixture (a mixture of magnesium hydride and silicon hydride) is consumed. Hence, to produce 180 liters 0.5 ppm hydrogen-rich water, 64.8 g of the metal hydride mixture will be consumed. The extra cost required to produce 1 cubic meter concrete using calcium chloride and hydrogen-rich water is calculated as follows: Table S2. The extra cost required to produce 1 cubic meter concrete using calcium chloride and hydrogen-rich water (consumed cement and water are 360 kg and 180 liters, respectively) Type of concrete
Dose of calcium chloride 2% w.r.t. weight of cement4-6
Dose of hydrogenrich water --
Total amount of calcium chloride (kg) 7.2
Total amount of metal hydride (g) --
Cost/ container (USD) 10.95/ 500 g containera
Total cost (USD) 157.68b
Calcium chloride based concrete Hydrogen- -0.5 ppm -64.8 12.5 / 20 g 40.5d c rich water (present container based study) concrete a Cost of calcium chloride per 500 g container reported in http://www.sciencecompany.com/Calcium-Chloride-Lab-Grade-500g-P6381.aspx, bExtra cost needed for the fabrication of 1 cubic meter calcium chloride based concrete, ccost of the metal hydride mixture per 20 g container reported in www.h2vision.co.kr, dExtra cost needed for the fabrication of 1 cubic meter hydrogen-rich water based concrete.
S3
Figure S1. The particle size distribution curve of the ordinary Portland cement used in this investigation Table S3. Chemical composition of the ordinary Portland cement used in this investigation Cement Ordinary Portland cement *Loss of ignition
SiO2 20.36
Al2O3 5.77
Chemical compositions (%) Fe2O3 CaO MgO Na2O 2.84 64.33 2.05 0.00
LI* 2.00
S4
Figure S2. Variation of the hydrogen-rich water concentration with the increase in time (min).
S5
Figure S3. The typical fitting and deconvolution of the XRD pattern of 1, 3, 7, and 28 days hydrated control cement (0CC) and 0.5 ppm hydrogen-rich water based cement (0.5HC) sample, (A) 0CC-1day, (B) 0CC-3days, (C) 0CC-7days, (D) 0CC-28days, (E) 0.5HC-1day, (F) 0.5HC3days, (G) 0.5HC-7days, and (H) 0.5HC-28days. S6
Figure S4. TG-DTG plot of the 7, 14 and 28 days hydrated control (0CC) and 0.5 ppm hydrogen-rich water based cement sample (0.5HC).
S7
References (1) Ramachandran, V. S. Concrete admixtures handbook properties, science and technology 2nd Edn.; Ramachandran, V. S., Ed.; Noyes Publications, New Jersey, USA, 1995. (2) Rixom, R.; Mailvaganam, N. Chemical admixtures for concrete 3rd Edn.; Rixom, R.; Mailvaganam, N., Eds.; E & FN Spon, 11 New Fetter Lane, London, 1999. (3) Aïtcin, P. C.; Flatt, R. J. Science and technology of concrete admixtures 1st Edn.; Aïtcin, P. C.; Flatt, R. J., Eds.; Woodhead publishing, Cambridge, UK, 2015. (4) Bower, J. The healthy house 4th Edn.; Bower, J., Ed.; The Healthy House Institute, Bloomington, IN, 2001. (5) Jo, B. W.; Chakraborty, S.; Sikandar, M. A.; Kim, H.; Kim, K. H. Hydrogen-rich water revealed benefits in controlling the physical and mechanical performances of cement mortar. Constr. Build. Mater. 2015, 100, 31–39. (6) Building code requirements for structural concrete (ACI 318-08) and commentary; ACI 318-2008; An ACI Standard; American Concrete Institute, Farmington Hills, MI 48331, USA, 2008. www.concrete.org. (7) Guidelines for concrete mix design proportioning [CED 2: Cement and concrete]; IS 10262-2009; Bureau of Indian Standards: New Delhi, India, 2009.
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