scholarly journals Preparation of Electric- and Magnetic-Activated Water and Its Influence on the Workability and Mechanical Properties of Cement Mortar

2021 ◽  
Vol 13 (8) ◽  
pp. 4546
Author(s):  
Kaiyue Zhao ◽  
Peng Zhang ◽  
Bing Wang ◽  
Yupeng Tian ◽  
Shanbin Xue ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Cement Paste ◽  
Cement Mortar ◽  
Environmental Issues ◽  
Chemical Admixtures ◽  
Untreated Water ◽  
Alternating Voltage

Cement-based materials prepared with activated water induced by a magnetic field or electric field represent a possible solution to environmental issues caused by the worldwide utilization of chemical admixtures. In this contribution, electric- and magnetic-activated water have been produced. The workability and mechanical properties of cement mortar prepared with this activated water have been investigated. The results indicate that the pH and absorbance (Abs) values of the water varied as the electric and magnetic field changed, and their values increased significantly, exhibiting improved activity compared with that of the untreated water. In addition, activated water still retains activity within 30 min of the resting time. The fluidity of the cement paste prepared with electric-activated water was significantly larger than that of the untreated paste. However, the level of improvement differed with the worst performance resulting from cement paste prepared with alternating voltage activated water. In terms of mechanical properties, both compressive strength and flexural strength obtained its maximum values at 280 mT with two processing cycles. The compressive strength increased 26% as the curing time increased from 7 days to 28 days and flexural strength increased by 31%. In addition, through the introduction of magnetic-activated water into cement mortar, the mechanical strength can be maintained without losing its workability when the amount of cement is reduced.

scholarly journals Effect of Graphene Oxide/Graphene Hybrid on Mechanical Properties of Cement Mortar and Mechanism Investigation

Nanomaterials ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 113 ◽  
Author(s):  
Hongfang Sun ◽  
Li Ling ◽  
Zhili Ren ◽  
Shazim Ali Memon ◽  
Feng Xing
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Graphene Oxide ◽  
Flexural Strength ◽  
Pore Size Distribution ◽  
Cement Mortar ◽  
Underlying Mechanism ◽  
Mortar Specimen ◽  
Degree Of Hydration ◽  
Cement Mortars

This paper evaluated the effect of graphene oxide/graphene (GO/GR) hybrid on mechanical properties of cement mortar. The underlying mechanism was also investigated. In the GO/GR hybrid, GO was expected to act as a dispersant for GR while GR was used as reinforcement in mortar due to its excellent mechanical properties. For the mortar specimen, flexural and compressive strength were measured at varied GO to GR ratios of 1:0, 3:1, 1:1, 1:3, and 0:1 by keeping the total amount of GO and GR constant. The underlying mechanism was investigated through the dispersibility of GR, heat releasing characteristics during hydration, and porosity of mortar. The results showed that GO/GR hybrid significantly enhanced the flexural and compressive strength of cement mortars. The flexural strength reached maximum at GO:GR = 1:1, where the enhancement level was up to 23.04% (28 days) when compared to mortar prepared with only GO, and up to 15.63% (7 days) when compared to mortar prepared with only GR. In terms of compressive strength, the enhancement level for GO:GR = 3:1 was up to 21.10% (3 days) when compared with that of mortar incorporating GO only. The enhancement in compressive strength with mortar at GO:GR = 1:1 was up to 14.69% (7-day) when compared with mortar incorporating GR only. In addition to dispersibility, the compressive strength was also influenced by other factors, such as the degree of hydration, porosity, and pore size distribution of mortar, which made the mortars perform best at different ages.

The Preparation and Pozzolanic Activity of Metakaolin Admixtures

2013 ◽  
Vol 539 ◽  
pp. 230-234 ◽  
Author(s):  
Bao Min Wang ◽  
Yuan Zhang ◽  
Ming Li
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Cement Paste ◽  
Cement Mortar ◽  
Heat Treating ◽  
Ratio Method ◽  
Strength Ratio ◽  
Hydration Products ◽  
Burning Temperature ◽  
Optimum Proportion

The optimum burning temperature of kaolinite and the optimum proportion of metakaolin (MK) in cement paste were studied by the compressive strength ratio method. Metakaolin was obtained at different burning temperature of 700°C, 750°C, 800°C and 850°C for 4 hours, and mixed into cement with the incorporation of 0, 5wt.%, 10wt.%, 15wt.% and 20wt.%. At last, the mechanical properties were researched. The influence of different burning temperature on hydration products of metakaolin cement mortar were analyzed. The results show that the compressive strength ratio of metakaolin cement mortar and the metakaolin pozzolanicity reach the maximum when the metakaolin obtained by heat treating of 750°C, the optimum proportion of metakaolin in cement is 10%~15%.

Effect of Admixtures on the Performance of Recycled Fine Aggregate Cement Mortar

2014 ◽  
Vol 548-549 ◽  
pp. 1663-1666
Author(s):  
Fu Xing Wang ◽  
Guo Zhong Li ◽  
Juan Chen
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Osmotic Pressure ◽  
Cement Mortar ◽  
Fine Aggregate ◽  
Hydration Products ◽  
Polycarboxylate Superplasticizer ◽  
Recycled Fine Aggregate ◽  
Micro Morphology

The effect of admixtures on the mechanical properties of recycled fine aggregate cement mortar was studied. The result indicated that compared with blank samples the 28d flexural strength, the compressive strength and osmotic pressure of cement mortar were increased by 15.6%, 35.5%, 41.1% respectively when adding silicone waterproofing agent 0.2wt%, naphdalin series water reducer 1.0wt%, polycarboxylate superplasticizer 0.8wt%. The micro-morphology and hydration products of mortar specimens was observed by SEM, XRD respectively.

The Study on Mechanical Properties and Microstructure of Cement Paste with Nano-TiO2

2012 ◽  
Vol 629 ◽  
pp. 477-481 ◽  
Author(s):  
Li Chao Feng ◽  
Chun Wei Gong ◽  
Yun Peng Wu ◽  
De Cheng Feng ◽  
Ning Xie
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Cement Paste ◽  
Strength Testing ◽  
Good Dispersion

Cement paste with addition of a small amount of (0.9wt%) nano-TiO2 were prepared. Flexural strength and compressive strength testing results showed that by adding a small amount of nano TiO2 with good dispersion, the 28-day flexural strength and compressive strength of cement paste modified by nano-TiO2 was increased by 16.12%, and 14.15%, respectively.

scholarly journals Mechanical Properties of Polypropylene Fiber Cement Mortar under Different Loading Speeds

2021 ◽  
Vol 13 (7) ◽  
pp. 3697
Author(s):  
Hui Chen ◽  
Xin Huang ◽  
Rui He ◽  
Zhenheng Zhou ◽  
Chuanqing Fu ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Relative Error ◽  
Cement Mortar ◽  
Polypropylene Fiber ◽  
Experimental Results ◽  
Strength Tests ◽  
Sample Age

In this work, the relationships between the mechanical properties (i.e., compressive strength and flexural strength) and loading speed of polypropylene fiber (PPF)-incorporated cement mortar at different ages (before 28 days) were studied. A total of 162 cubic samples for compressive strength tests and 162 cuboid samples for flexural strength tests were casted and tested. Analytical relationships between the sample properties (i.e., sample age, PPF content, and loading speed) and compressive and flexural strength were proposed based on the experimental data, respectively. Of the predicted compressive and flexural strength results, 70.4% and 75.9% showed less than 15% relative error compared with the experimental results, respectively.

Effect of Nano silica on strength and water absorption of cement mortar Exposed low pressure environment

2021 ◽  
Vol 06 ◽  
Author(s):  
Ai Zhang ◽  
Yong Ge
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Water Absorption ◽  
Cement Mortar ◽  
Strength Loss ◽  
Low Pressure ◽  
Low Humidity ◽  
Strength And Durability ◽  
Humidity Environment

Background: Buildings in high altitude region often face low pressure and low humidity service environment, which has a great impact on the mechanical properties and durability of cement-based materials. Objective: In this paper, the effects of nano-silica (NS) on the strength and water absorption of cement mortar exposed to the low pressure and low humidity environment were studied. Methods: Mechanical properties (compressive strength and flexural strength) and durability (water absorption) were measured. And the hydration degree of cement was tested to assist analysis. Results: The flexural strength of mortar decreased and the compressive strength increased slowly after 28 days of exposure under low pressure and low humidity environment. Especially, the introduction of 1% NS could reduce the compressive strength loss and flexural strength loss of mortar under low pressure and low humidity environment. It was also found that the water absorption of the mortar in low pressure and low humidity environment was related to the tortuous degree of the pores inside the specimen. Conclusion: The introduction of 1% NS contributed the most to the mechanical properties (compressive strength and flexural strength) and durability (water absorption) of cement mortar.

scholarly journals Performance of Carbon Fiber Filament Reinforcing Cement Mortar

2021 ◽  
Vol 7 (10) ◽  
pp. 1693-1701
Author(s):  
Ahmed Hamed El-Sayed Salama ◽  
Walid Fouad Edris
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Carbon Fiber ◽  
Flexural Strength ◽  
Cement Mortar ◽  
Physical And Mechanical Properties ◽  
Experimental Program ◽  
Flow Table ◽  
Compressive And Flexural Strengths ◽  
Measured Density

This paper aims to study the effect of Carbon Fiber Filament (CFF) with different ratios and lengths on the physical and mechanical properties of cement mortar. An experimental program included 3 cm fixed length of CFF with 0, 0.25, 0.5, 0.75, and 1% different ratios by weight of cement addition were used in cement mortar cubes. Another experimental program of 0.5% CFF ratio with 1, 2, 3, 4, and 5 cm different lengths by weight of cement addition was used in cement mortar prisms. The physical and mechanical properties of cement mortar containing CFF were experimentally investigated at 7 and 28 days of curing. Workability, by means of flow table test, were measured. Density is conducted for cubes and prisms at the age of 28 days. At ages of 7 and 28 days, compressive and flexural strengths were studied. The study showed a reduction in workability with the increase of CFF ratios and lengths by 0.0 to 2.7% and by 0.9 to 5.4% respectively. Moreover, an improvement in density, compressive, and flexural strengths was observed. At ages of 7 and 28 days, the results showed that compressive strength increased by 33 and 31% respectively at 0.5% of CFF ratio while the flexural strength increased by 125 and 327% respectively with CFF length of 5 cm. Doi: 10.28991/cej-2021-03091753 Full Text: PDF

Mechanical Properties and Microstructures of Cement Mortar Modified with Styrene-Butadiene Polymer Emulsion

2010 ◽  
Vol 168-170 ◽  
pp. 190-194 ◽  
Author(s):  
Zhen Jun Wang ◽  
Rui Wang ◽  
Yu Bin Cheng
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Cement Mortar ◽  
Strength Increase ◽  
Polymer Emulsion ◽  
Cement Ratio ◽  
Cement Mortars ◽  
Water To Cement Ratio ◽  
Styrene Butadiene

In this paper, styrene-butadiene polymer emulsion SD622S was adopted to modify cement mortar; mechanical properties of cement mortars were studied and microstructures was analyzed by means of Scanning Electron Microscope (SEM) and Specific Surface Area & Pore Distribution Analyzer. The results show that in contrast to ordinary cement mortar, if water to cement ratio (W/C) is constant, compressive strength of modified cement mortar can decrease, while flexural strength and toughness, ratio of compressive strength to flexural strength, increase with the increase of polymer to cement ratio in mass (P/C) at 7 and 28 curing days. With the increase of P/C, net structure made from polymer and cement hydration products is developed and pore whose size is smaller than 200Å begins to increase, which indicates pore diameters in modified cement mortar change to be finer. So microstructures of modified cement mortar become denser and display higher toughness.

Effect of Multi-Walled Carbon Nanotubes on Mechanical Properties and Durability of Latex-Modified Cement Mortar

2016 ◽  
Vol 711 ◽  
pp. 232-240 ◽  
Author(s):  
Ling Shi Meng ◽  
Christopher K.Y. Leung ◽  
Geng Ying Li
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Cement Mortar ◽  
Cement Composite ◽  
Cementitious Materials ◽  
Chloride Diffusion ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

This paper studies the effects of multi-walled carbon nanotubes (MWCNTs) on the mechanical properties and durability of polymer latex-modified cement mortar. Latex-modified cementitious materials possess many advantages. However, reduction of mechanical properties due to the introduction of an amorphous structure within the cement composite has limited its application. In this study, multi-walled carbon nanotubes functionalised with carboxyl group (MWCNTs-COOH), ranging from 0% to 0.15% by weight, are added into mortar modified with 0.6 wt.% polyvinyl alcohol (PVA) latex. Mechanical properties including compressive strength and flexural strength are measured. Water absorption test and rapid chloride diffusion test are performed to assess durability performance. Results indicate considerable increase of compressive strength and flexural strength, as well as improvement in durability, by the addition of MWCNTs-COOH. With Scanning Electron Microscopy conducted on both the latex solution and cement composite, the microstructural changes resulted from MWCNT addition are revealed.

Mechanical Properties of novel hardened cement paste reinforced with Multi-Walled Carbon Nano-Tubes (MWCNTs) and Glass Fibers Nano material

2021 ◽  
Vol 8 (1) ◽  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Cement Paste ◽  
Tap Water ◽  
Glass Fibers ◽  
Flexural Modulus ◽  
Maximum Load ◽  
Hardened Cement ◽  
Glass Fibres

To improve the mechanical and durability properties of ordinary Portland cement (OPC) mortar and paste, the incorporation of multi walled Carbon nanotubes (MWCNTs) and their dispersion procedures, functionalization, and ultra sonication have been intensively implemented. Most of the studies showed significant enhancements in the mechanical properties of OPC mortar or paste; however, others showed impairments. The recent studies regarding the implementation of MWCNTs and Glass Fibres on the mechanical properties of OPC paste and mortar were reviewed and these properties include compressive, tensile, flexural strengths, and elastic modulus. A statistical study was conducted to evaluate the mechanical properties of concrete by dispersion of MWCNT’s and Glass Fibres in the cement paste. In these composites, the percentage of MWCNTs was fixed at 0.75% by weight of cement, while the percentage of Glass Fibers was fixed at 0.25% by weight of cement. The samples were cured in tap water for 28 days at 25 + 2?C.Composite specimens were tested for compression and flexure in order to evaluate their mechanical properties such as compressive strength, flexural strength, toughness and ductility and compared with the results of plain cement control beams. The maximum deflection was found to be 0.5mm with a maximum load of 500N. The flexural strength was observed to be 1250.50 N/mm2 as per ASTM D 790 which is 20% more than the flexural strength obtained with Plain Cement+MWCNT’s and 60 to 70% more than that obtained with Plain Cement + Glass Fibres. The flexural modulus as per deflection criteria is 535.94 N/mm2 which is 10 to 20% more than that obtained of Plain Cement+MWCNT’s and Plain Cement+ Glass Fibres. The compressive strength of Plain Cement+0.75% MWCNT’s+0.25% Glass fibres was found to be 65 N/mm2 which is greater than Plain cement and Plain cement+MWCNT’s. Surface morphology by Scanning Electron microscopy of the specimens infers the clustering of glass fibres and demonstr

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