scholarly journals Effect of Carboxymethyl Cellulose on the Properties of Ordinary Portland Cement

1970 ◽  
Vol 45 (1) ◽  
pp. 1-8 ◽  
Author(s):  
KN Farooque ◽  
Z Yeasmin ◽  
ME Halim ◽  
AJ Mahmood ◽  
MYA Mollah
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Carboxymethyl Cellulose ◽  
Ordinary Portland Cement ◽  
Setting Time ◽  
Bound Water ◽  
Acid Resistance ◽  
Organic Polymer ◽  
Hardened Cement ◽  
X Ray Diffraction

Organic Polymer carboxymethyl cellulose (CMC) (0.25, 0.50 and 1.5% solution) was incorporated in Ordinary Portland Cement (OPC) and its effect on compressive strength, setting time, porosity, corrosive resistance, density and water absorbance have been studied. Organic polymer retards the setting time and a small increase in compressive strength was observed after 90 days for 0.5% CMC. Addition of polymer has been found to be effective in improving the acid resistance of OPC. Interaction of CMC with OPC causes decrease in water absorption, porosity and chemically bound water. X-ray diffraction of OPC-CMC pastes after 4 months and 1 year display some new peaks as well as disappearance of few peaks showing interaction of CMC with hydrated cementitious pastes. Examination of microstructure reveals that fibre types of matters were formed in hardened cement paste. Key words: Ordinary portland cement; Carboxymethyl cellulose (CMC); Compresssive strength; Porosity; XRD; SEM. DOI: 10.3329/bjsir.v45i1.5171 Bangladesh J. Sci. Ind. Res. 45(1), 1-8, 2010

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 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.

scholarly journals Strength development of cement-treated sand using different cement types cured at different temperatures

2018 ◽  
Vol 195 ◽  
pp. 01006
Author(s):  
Lanh Si Ho ◽  
Kenichiro Nakarai ◽  
Kenta Eguchi ◽  
Takashi Sasaki ◽  
Minoru Morioka
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Cement Content ◽  
Bound Water ◽  
Pozzolanic Reaction ◽  
Strength Development ◽  
Different Temperatures ◽  
Early Strength

This study aimed to investigate the strength development of cement-treated sand using different cement types: ordinary Portland cement (OPC), high early strength Portland cement (HPC), and moderate heat Portland cement (MPC) cured at different temperatures. The cementtreated sand specimens were prepared with 8% of cement content and cured under sealed conditions at 20οC and 40οC, and mortar specimens were also prepared for reference. The results showed that the compressive strength of cement-treated sand increased in order of MPC, OPC, and HPC under high curing temperatures. It was interesting that the compressive strength of the specimens using HPC was much larger than that of the specimen using OPC and MPC under 20οC due to the larger amount of chemically bound water. Additionally, it was revealed that under high curing temperatures, the pozzolanic reaction was accelerated in the cement-treated sand; this may be caused by the high proportions of sand in the mixtures.

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.

scholarly journals Evaluation of external sulfate attack (Na2SO4 and MgSO4): Portland cement mortars containing siliceous supplementary cementitious materials

2020 ◽  
Vol 13 (4) ◽  
Author(s):  
Diego Jesus de Souza ◽  
Marcelo Henrique Farias de Medeiros ◽  
Juarez Hoppe Filho
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Cementitious Materials ◽  
Sulfate Attack ◽  
Supplementary Cementitious Materials ◽  
Hardened Cement ◽  
X Ray Diffraction ◽  
Sulfate Ions ◽  
Cement Mortars ◽  
Physical And Chemical

ABSTRACT: Sulfate attack is a term used to describe a series of chemical reactions between sulfate ions and hydrated compounds of the hardened cement paste. The present study aims to evaluate the physical (linear expansion, flexural and compressive strength) and mineralogical properties (X-ray diffraction) of three different mortar compositions (Portland Cement CPV-ARI containing silica fume and rice husk ash, in both cases with 10% replacement of the cement by weight) against sodium and magnesium sulfate attack (concentration of SO42- equal to 0.7 molar). The data collected indicate that the replacing the cement by the two siliceous supplementary cementitious materials (SCMs) generate similar results, both SCMs were able to mitigate the effects of the sodium sulfate attack in both physical and chemical characteristics, however, both materials increase the deterioration (i.e. compressive strength) when exposed to MgSO4 solution.

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 EFFECT OF PARTIAL REPLACEMENT OF CEMENT WITH RICE HUSK ASH AND CELLULOSE INDUSTRIAL RESIDUE ON COMPRESSIVE STRENGTH OF CONCRETE

2019 ◽  
pp. 1-9
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Rice Husk ◽  
Ordinary Portland Cement ◽  
Rice Husk Ash ◽  
Setting Time ◽  
Research Work ◽  
Partial Replacement ◽  
Control Test ◽  
Industrial Residue

In this research work, the effect of rice husk ash on concrete produced with cellulose industrial residue was studied. A mix proportion of 1:1.8:3.7 with water cement ratio of 0.47 were used. The percentage replacement of Ordinary Portland Cement (OPC) with cellulose industrial residue and rice husk ash used were 0%, 5%, 10%, 20% 30% and 40%. Concrete cubes of 150mm x 150mm x 150mm of Ordinary Portland Cement/Cellulose Industrial Residue and Ordinary Portland Cement/Cellulose Industrial Residue/Rice Ash were cast and cured at 3,7,28,60 and 90 days respectively. At the end of each hydration period, the concrete cubes were crushed and their compressive strength were determined. The result of compressive strength of 5-40% replacement of cement with cellulose industrial residue ranges from 13.02-32.81 N/mm2 as against 25.60-42.08N/mm2 for the control test. The result of the compressive strength of 5-40% replacement of cement with Cellulose Industrial Residue and Rice Husk Ash ranges from 13.17-36.30N/mm2 as against 25.60-42.08N/mm2 for the control test. The result of the initial and final setting time of Ordinary Portland Cement/Cellulose Industrial Residue and Cement/Cellulose Industrial Residue/Rice Husk Ash for 5-40% replacement of cement ranges from 61-118mins, 58-110mins and 620 – 836mins, 598 – 799mins respectively as against 52mins and 590mins for the control test. The main conclusion of this study is that the incorporation rice husk ash into cellulose industrial residue increase the strength of concrete produced. The objective of this study is to assess the strength of concrete produced when two pozzolanic materials were used to replace cement in producing concrete.

Study on Waterproof and Water-Resistant Properties of Gypsum

2012 ◽  
Vol 476-478 ◽  
pp. 1585-1588
Author(s):  
Hong Pan ◽  
Guo Zhong Li
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Portland Cement ◽  
Water Absorption ◽  
Ordinary Portland Cement ◽  
Experimental Results ◽  
Softening Coefficient

The comprehensively modified effect of cement, VAE emulsion and self-made acrylic varnish on mechanical and water-resistant properties of gypsum sample was investigated and microstructure of gypsum sample was analyzed. Experimental results exhibit that absolutely dry flexural strength, absolutely dry compressive strength, water absorption and softening coefficient of gypsum specimen with admixture of 10% ordinary Portland cement and 6% VAE emulsion and acrylic varnish coated on its surface can respectively reach to 5.11MPa , 10.49 MPa, 8.32% and 0.63, respectively.

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