Calcined Kaolin Geopolymeric Powder: Influence of Water-to-Geopolymeric Powder Ratio

2012 ◽  
Vol 548 ◽  
pp. 48-53
Author(s):  
Y.M. Liew ◽  
H. Kamarudin ◽  
A.M. Mustafa Al Bakri ◽  
M. Binhussain ◽  
Luqman Musa ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Setting Time ◽  
Sem Analysis ◽  
Cement Ratio ◽  
Water To Cement Ratio ◽  
Influence Of Water ◽  
Calcined Kaolin ◽  
Geopolymer Paste

This paper describes the synthesis of calcined kaolin geopolymeric powder from the alkaline activation of calcined kaolin followed by solidification and pulverizing process. The geopolymeric powder was used by just adding water to produce resulted geopolymer paste. In this paper, the effect of water-to-geopolymeric powder ratios on the properties of the resulted geopolymer paste was studied. This water-to-geopolymer powder ratio was similar to that of water-to-cement ratio in the case of ordinary Portland cement (OPC). However, the concept used here was based on geopolymerization process. The compressive strength, setting time and SEM analysis of the resulted geopolymer pastes were conducted. Highest strength was achieved at water-to-geopolymer powder ratio of 0.22. The resulted geopolymer paste could be handled up to 120 minutes and reached final setting after about 4 hours of setting. Microstructure showed the formation of geopolymeric gel after the addition of water to the geopolymeric powder.

scholarly journals The Effect of Nano Metakaolin Material on Some Properties of Concrete

2013 ◽  
Vol 6 (1) ◽  
pp. 50-61
Author(s):  
Amer M. Ibrahem ◽  
Shakir A. Al-Mishhadani ◽  
Zeinab H.Naji
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Portland Cement ◽  
Water Absorption ◽  
Thermal Activation ◽  
Ordinary Portland Cement ◽  
Splitting Tensile Strength ◽  
Kaolin Clay ◽  
Cement Ratio ◽  
Water Cement Ratio

This investigation aimed to study the effect of nano metakaolin ( NMK ) on some properties (compressive strength ,splitting tensile strength & water absorption ) of concrete. The nano metakaolin (NMK) was prepared by thermal activation of kaolin clay for 2 hours at 750 Ċ. The cement used in this investigation consists of ordinary Portland cement (OPC). The OPC was partially substituted by NMK of ( 3, 5 & 10%) by weight of cement. The C45 concrete was prepared , using water/cement ratio ( W/c) of (0.53) .The Water absorption was tested at 28 days while the tests (compressive strength ,splitting tensile strength) were tested at ages of (7, 28, 60,& 90) days . The compressive strength and splitting tensile strength of concrete with NMK were higher than that of reference concrete with the same W/c ratio.The improvement in the compressive strength when using NMK was (42.2, 55.8 , 63.1% ) at age 28 days for ( 3%, 5%, &10% ) replacement of NMK respectively whereas the improvement in the splitting tensile strength was (0% , 36% & 46.8 %) at age of 28 days when using (3%, 5%, &10% ) NMK respectively. The improvement in the water absorption was (16.6%, 21.79%, &25.6 ) when using (3, 5, &10% )NMK.

Effect of Alkaline Solution to Fly Ash Ratio on Geopolymer Mortar Properties

2017 ◽  
Vol 733 ◽  
pp. 85-88 ◽  
Author(s):  
Amir Fauzi ◽  
Mohd Fadhil Nuruddin ◽  
Ahmad B. Malkawi ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Bashar S. Mohammed
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Portland Cement ◽  
Alkaline Solution ◽  
Similar Pattern ◽  
Ordinary Portland Cement ◽  
Setting Time ◽  
Pozzolanic Reaction

Geopolymer system is new binding materials in concrete industry that is produced by the alkaline solution and materials rich in aluminosilicate such as fly ash. The effect of the alkaline solution to fly ash ratios of 0.3, 0.4 and 0.5 on mortar geopolymer properties was an issue in this study. The results showed that the higher alkaline solution to fly ash ratio improves the workability and brings a longer setting time, whereas the lower alkaline solution to fly ash ratio gains the significant compressive strength. It was a similar pattern with conventional mortar used ordinary Portland cement, which the compressive strength at 7 days was 85%-90% for 28 days compressive strength, whereas conventional mortar is only 65%-75%. This was due to the higher reactivity in geopolymer system that was faster than the pozzolanic reaction.

scholarly journals Influence of Water-Cement Ratio and Type of Mixing Water on the Early Hydration Performance of Calcium Sulphoaluminate (CSA) Cement

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Chuanlin Wang ◽  
Meimei Song
Keyword(s):  
Compressive Strength ◽  
Physical Properties ◽  
Setting Time ◽  
Hydration Process ◽  
Chemical Shrinkage ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Influence Of Water ◽  
Calcium Sulphoaluminate ◽  
Mixing Water

The present work studies the influence of water-cement ratio and types of mixing water on the hydration process and microstructure of calcium sulphoaluminate (CSA) cement. Experimental tests on the setting time, physical properties, compressive strength, chemical shrinkage, X-ray diffraction (XRD), and scanning electron microscopy (SEM) of CSA cement paste were carried out. The XRD analysis confirmed that the main hydration product is ettringite in both freshwater and seawater mixed CSA cement with different w/c ratios. The SEM analysis and physical properties test show that both low w/c ratio and seawater can improve the microstructure of CSA cement. The test results also find out that the high w/c ratio can accelerate the hydration process, extend the setting time, lower the compressive strength, and increase the chemical shrinkage of CSA cement, and the seawater presents a similar influence except for the mechanical property. The seawater increases the compressive strength of CSA cement in the early stage of hydration but will increase the microcracks at the later hydration stage of CSA cement and reduce its mechanical properties.

scholarly journals Comparison of Effects of Sodium Bicarbonate and Sodium Carbonate on the Hydration and Properties of Portland Cement Paste

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1033 ◽  
Author(s):  
Yuli Wang ◽  
Fengxia He ◽  
Junjie Wang ◽  
Qianku Hu
Keyword(s):  
Compressive Strength ◽  
Sodium Bicarbonate ◽  
Portland Cement ◽  
Cement Paste ◽  
Sodium Carbonate ◽  
Ordinary Portland Cement ◽  
Setting Time ◽  
Sprayed Concrete ◽  
Final Setting Time ◽  
Portland Cement Paste

Carbonates and bicarbonates are two groups of accelerators which can be used in sprayed concrete. In this study, the effects of the two accelerators sodium carbonate (Na2CO3) and sodium bicarbonate (NaHCO3) (0%, 1%, 2%, 3%, and 4% by weight of ordinary Portland cement OPC) on the properties of OPC paste were compared. The results show that both of them could accelerate the initial and final setting time of OPC paste, but the effect of the two accelerators on the compressive strength were different. After 1 day, sodium bicarbonate at 3% had the highest strength while sodium carbonate at 1% had the highest strength. After 7 days, both of the two accelerators at 1% had the highest compressive strength. After 28 days, the compressive strength decreased with the increase of the two. The improved strength at 1 and 7 days was caused by the accelerated formation of ettringite and the formation of CaCO3 through the reactions between the two with portlandite. The decrease of strength was caused by the Na+ could reduce the adhesion between C-S-H gel by replacing the Ca2+. NaHCO3 was found be a better accelerator than Na2CO3.

Influence of Curing on Calcined Kaolin-Based Geopolymer

2016 ◽  
Vol 690 ◽  
pp. 200-205
Author(s):  
Narumon Lertcumfu ◽  
Sukum Eitssayeam ◽  
Kamonpan Pengpat ◽  
Tawee Tunkasiri ◽  
Denis Russell Sweatman ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Portland Cement ◽  
Microwave Heating ◽  
Production Line ◽  
Room Temperature ◽  
Ordinary Portland Cement ◽  
Microwave Curing ◽  
Alternative Material ◽  
Calcined Kaolin

The object of this work was to use calcined kaolin-based geopolymer as an alternative material to replace ordinary Portland cement (OPCs) by applying geopolymerization processes. Geopolymer slurry was prepared from calcined kaolin and alkali activators, which consisted of 10 M NaOH and Na2SiO3 solution. The fresh slurry was cast into plastic molds and then cured at room temperature for 24 h. Reaction temperatures were measured (for 24 hours after casting). Compressive strength of the geopolymer was tested after curing at room temperature and after microwave heating. The mechanical properties increased with added plaster for microwave curing of 5 min. It is believed that this process can increase the efficiency of the production line for geopolymer.

Using High Temperature for Improve Compressive Strength of Ordinary Portland Cement Paste (OPC) – A New Approach

2014 ◽  
Vol 894 ◽  
pp. 70-76
Author(s):  
Abdoullah Namdar ◽  
Fadzil Mat Yahaya ◽  
Mashita Mohd Yusoff
Keyword(s):  
Surface Roughness ◽  
Compressive Strength ◽  
Portland Cement ◽  
Cement Paste ◽  
Ordinary Portland Cement ◽  
Setting Time ◽  
New Approach ◽  
Force Microscopy ◽  
Atomic Force ◽  
Portland Cement Paste

Cement paste was replaced with kaolin-bentonite. The specimens were exposed to elevated temperature for 3 hours in a ceramic furnace and cooled down to room temperature. After cooling, the effect of kaolin-bentonite (particles sized of < 45μm) on hydration, rehydration, surface roughness and compressive strength of ordinary Portland cement (OPC) paste were investigated. Atomic Force Microscopy (AFM) was used to study surface roughness of OPC paste-additive mixture. The application of fire on OPC paste was analyzed. The results showed imposed heat (500 oC for 3 hours) accelerates the hydration process of OPC, and reduces setting time. Increased heat to 1000 oC, leads to zero compressive strength of specimens, the compressive strength of OPC continuously reduces after specimen has fully cooled down. A method for recovery of compressive strength of OPC after offing fire has been suggested. The method of offing fire has important effects on the compressive strength of concrete. The best results for specimen content are cement-kaolin-bentonite paste, exposure to 500 o C, after 90 days of curing, and cooling down in water. In this case the compressive strength has been increased around 60 % compared to not using additive and not exposing to heat.

Accelerating the Setting of Portland Cement Based Dental Materials Using Calcium Sulphates

2007 ◽  
Vol 361-363 ◽  
pp. 343-346 ◽  
Author(s):  
J.L. O’Beirne ◽  
R.M. Shelton ◽  
P.J. Lumley ◽  
M.P. Hofmann
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Setting Time ◽  
Dental Materials ◽  
Testing Machine ◽  
Mineral Trioxide Aggregate ◽  
Calcium Sulphate ◽  
Sem Analysis ◽  
Initial Setting ◽  
Relative Porosity

Mineral trioxide aggregate (MTA) is a Portland cement (PC) based material used for sealing root canals however it has a long setting time which is undesirable for dental applications. This study investigated the effect of three different calcium sulphate additions for accelerating the initial setting of a PC based dental material, whilst attempting to maintain its high compressive strength and low relative porosity. Anhydrous calcium sulphate (CaS), Plaster of Paris, calcium sulphate hemihydrate (PoP) and Gypsum, calcium sulphate dihydrate (Gyp) were each added to PC at 5wt%, 10wt% and 20wt%. Initial setting times, compressive strengths and relative porosity were measured using the Gilmore Needles Test, a universal testing machine and a helium pycnometer respectively. Scanning electron microscopy (SEM) was used to observe any microstructural changes in cements. PoP and CaS had the most profound influence on the setting of PC. 20wt% CaS had the greatest effect on the setting time of PC (10min) although decreased the compressive strength by up to 40%, which may have arisen from the formation of microcracks, observed by SEM analysis. Additions of 10wt% PoP and CaS may have the potential to reduce the long setting time of PC based dental materials.

scholarly journals Graphene Nanoplatelets Impact on Concrete in Improving Freeze-Thaw Resistance

2019 ◽  
Vol 9 (17) ◽  
pp. 3582 ◽  
Author(s):  
Guofang Chen ◽  
Mingqian Yang ◽  
Longjun Xu ◽  
Yingzi Zhang ◽  
Yanze Wang
Keyword(s):  
Compressive Strength ◽  
Ordinary Portland Cement ◽  
Graphene Nanoplatelets ◽  
Compressive Property ◽  
Cement Ratio ◽  
Freeze Thaw ◽  
Ordinary Concrete ◽  
Water To Cement Ratio ◽  
Chinese Standard ◽  
Better Than

Graphene nanoplatelets (GNP) is a newly nanomaterial with extraordinary properties. This paper investigated the effect of GNP on the addition on freeze–thaw (F–T) resistance of concrete. In this experimental study, water to cement ratio remained unchanged, a control mixture without GNP materials and the addition of GNP was ranging from 0.02% to 0.4% by weight of ordinary Portland cement was prepared. Specimens were carried out by the rapid freeze-thaw test, according to the current Chinese standard. The workability, compressive strength, visual deterioration and mass loss of concrete samples were evaluated. Scanning electron microscopy also applied in order to investigate the micromorphology inside of the concrete. The results showed that GNP concrete has a finer pore structure than ordinary concrete; moreover, the workability of GNP concrete reduced, and the compressive strength of specimens was enhanced within the appropriate range of GNP addition; in addition, GNP concrete performed better than the control concrete in the durability of concrete exposed to F-T actions. Specimens with 0.05% GNP exhibited the highest compressive property after 200 F–T cycles compared with other samples.

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