scholarly journals The impact of lithium nitrate on the physical and mechanical properties of Portland cement)

2018 ◽  
Vol 163 ◽  
pp. 04002
Author(s):  
Justyna Zapała-Sławeta ◽  
Zdzisława Owsiak
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Portland Cement ◽  
Isothermal Calorimetry ◽  
Setting Time ◽  
Physical And Mechanical Properties ◽  
Strength Development ◽  
Lithium Nitrate ◽  
Early Hydration ◽  
The Impact

The effectiveness of lithium nitrate as a chemical additive which reduces the negative effects of alkali aggregate reaction was subject to research by scientists in many centres around the world. The literature data on the impact of lithium nitrate on the physical and mechanical properties of cements are rare. Without a precise definition of the impact of lithium nitrate on the cement properties, it is extremely hard to determine its real advantages in practical usage. In this paper, studies were undertaken to assess the impact of LiNO3 on the properties of pastes and mortars with Portland cement. The rate of hydration of the cement with lithium additive was examined by isothermal calorimetry, measurements of setting time and phase composition of cement pastes in the initial stages of hydration. The influence of the admixture on the compressive strength development of mortars after 2, 7 and 28 days of hardening was also researched. Results indicate that lithium nitrate accelerates the early hydration of Portland cement, affecting the precipitation of hydration products. The compressive strength of mortars with lithium admixture decrease after 28 days, although 2 an 7-day strength were greater than the control mortars.

Influence of Portland Cement Addition in the Physical and Mechanical Properties of Epoxy Resin

2015 ◽  
Vol 1088 ◽  
pp. 411-414 ◽  
Author(s):  
Francisco Augusto Zago Marques ◽  
Carlos Eduardo G. da Silva ◽  
André Luis Christoforo ◽  
Francisco Antonio Rocco Lahr ◽  
Túlio Hallak Panzera ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Composite Material ◽  
Portland Cement ◽  
Physical Properties ◽  
Epoxy Resin ◽  
Modulus Of Elasticity ◽  
Epoxy Matrix ◽  
Physical And Mechanical Properties ◽  
Response Variable

This research evaluated, with the of the analyses of variance (ANOVA), a composite material based on epoxy matrix phase reinforced with Portland cement (CP-II) particles (0%wt [100%wt of resin], 20%wt, 40%wt, 60%wt). The response-variable investigated were modulus of elasticity (E) and compressive strength (S), bulk density (ρB), apparent density (ρA) and porosity (P). The highest values of the modulus of elasticity were provided from the composites manufactured with 40wt% of cement addition. The inclusion of 60% of cement implies in a reduction in the mechanical properties when compared with the results of the composite manufactured with 40% of cement. For the physical properties, the gradually inclusion of cement provides increasing in the density of the composites, and reduce the porosity of the materials manufactured.

scholarly journals Effect of fly ash on physical and mechanical properties of mortar

2019 ◽  
Vol 17 (6) ◽  
pp. 35
Author(s):  
Vu-An Tran
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Water Absorption ◽  
Thermal Power ◽  
Setting Time ◽  
Physical And Mechanical Properties ◽  
Flow Density ◽  
Control Specimen

This research investigates the physical and mechanical properties of mortar incorporating fly ash (FA), which is by-product of Duyen Hai thermal power plant. Six mixtures of mortar are produced with FA at level of 0%, 10%, 20%, 30%, 40%, and 50% (by volume) as cement replacement and at water-to-binder (W/B) of 0.5. The flow, density, compressive strength, flexural strength, and water absorption tests are made under relevant standard in this study. The results have shown that the higher FA content increases the flow of mortar but significantly decreases the density of mixtures. The water absorption and setting time increases as the samples incorporating FA. Compressive strength of specimen with 10% FA is approximately equal to control specimen at the 91-day age. The flexural strength of specimen ranges from 7.97 MPa to 8.94 MPa at the 91-day age with the best result for samples containing 10% and 20% FA.

scholarly journals Mechanical Properties of OPC - Geocement Concrete

2019 ◽  
Vol 8 (4) ◽  
pp. 3733-3736
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
External Heat ◽  
Partial Replacement ◽  
Strength Development ◽  
Strength Increase ◽  
Heat Curing ◽  
Compressive Strength Development

Nowadays geopolymer concretes are subjected to heat curing. A large amount of highly corrosive and the hygroscopic alkaline activators are nowadays generally utilized in producing geopolymer concretes. In this paper, hybrid Ordinary Portland Cement (OPC) and geopolymer mixes are developed. The mainly used activator id the Solid potassium carbonate at different percentage is used as 5% & 10% of the weight of geopolymeric materials and OPC was blended with geopolymeric materials in different proportions. By adding cement, improves all the geopolymer properties except workability. By Applying external heat, it plays an important role in gaining strength. Strength gained by the absence of external heat is achieved by using Portland cement as a partial replacement of geocement. The influence of OPC content on the compressive strength development is investigated, and the optimized amount of solid activator to be used in the mix is also investigated. It is observed that percentage of strength increase decreases from52.24% to 14.77% as the OPC content increased from 20% to 60%.

scholarly journals Exploring the Influence Factors of Early Hydration of Ultrafine Cement

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5677
Author(s):  
Yi Shi ◽  
Tao Wang ◽  
Haiyan Li ◽  
Shaoliang Wu
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Isothermal Calorimetry ◽  
Influence Factors ◽  
Particle Diameter ◽  
Curing Temperature ◽  
Strength Development ◽  
Cement Particle ◽  
Early Hydration ◽  
Ultrafine Cement

This work intends to contribute to the understanding of the influence factors of early hydration of ultrafine cement by focusing on the different fineness, different kinds of hardening accelerators, and different curing temperatures. Isothermal calorimetry, thermogravimetry, and X-ray diffraction (XRD) were performed to compare the hydration and chemical evolution of pastes containing accelerators with different fineness and curing temperatures; meanwhile, mechanical properties and water absorption were tested. The results showed that the cement fineness had a significant effect on the early hydration process; the smaller the cement particle size, the higher the early compressive strength. The 24 h compressive strength of ultrafine cement with a particle diameter of 6.8μm could reach 55.94 MPa, which was 118% higher than the reference cement. Water absorption test results indicated that adding 1% Ca(HCOO)2 to ultrafine cement can effectively reduce the water absorption, and it was only 1.93% at 28 d, which was 46% lower than the reference cement. An increase in curing temperature accelerated the activation of ultrafine cement in terms of the strength development rate, and the content of Ca(OH)2 in the ultrafine cement paste could reach 13.09% after being mixed with water for 24 h, which was 22% higher than that of the reference cement.

scholarly journals Performance and Durability of Rendering and Basecoat Mortars for ETICS with CSA and Portland Cement

2021 ◽  
Vol 6 (4) ◽  
pp. 60
Author(s):  
Tiago Trigo ◽  
Inês Flores-Colen ◽  
Luís Silva ◽  
Nuno Vieira ◽  
Ana Raimundo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Energy Consumption ◽  
Portland Cement ◽  
Bending Strength ◽  
Setting Time ◽  
Cement Matrix ◽  
Calcium Sulfoaluminate Cement ◽  
Calcium Sulfoaluminate ◽  
Composite Systems

The production of Portland cement (OP) is commonly associated to significant level of energy consumption and gas emissions. The use of calcium sulfoaluminate cement (CSA) can be a sustainable alternative binder, since its production releases about half of the CO2 emissions and its clinker requires 200 °C lower temperatures, when compared to OP. Furthermore, CSA has fast setting time and achieves higher strength in shorter periods, as well as reduced shrinkage. This paper discusses the incorporation of CSA in rendering mortars and basecoat mortars for ETICS (External Thermal Insulation Composite Systems). The physical-mechanical properties of mortars made with OP and CSA cements were experimental evaluated. The results showed that the introduction of CSA generally improves shrinkage, compressive strength, water absorption at low pressure, enhances the tensile bending strength and decreases the setting time. The amount of CSA introduced into the mixture significantly affected the properties of the cement matrix.

scholarly journals Peculiarities of hydration of Portland cement with synthetic nano-silica

2017 ◽  
Vol 12 (2) ◽  
pp. 101-106 ◽  
Author(s):  
Galyna Kotsay
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Portland Cement ◽  
Cement Hydration ◽  
Physical And Mechanical Properties ◽  
The Other ◽  
Nano Materials ◽  
Nano Silica ◽  
Other Hand ◽  
Materials Used

Abstract Application of nano-materials in cement products significantly, improves their properties. Of course, the effectiveness of the materials depends on their quantity and the way they are introduced into the system. So far, amongst nano-materials used in construction, the most preferred was nano-silica. This research investigated the effect of synthetic precipitated nano-silica on the cement hydration as well as, on the physical and mechanical properties of pastes and mortars. Obtained results showed that admixture of nano-silica enhanced flexural and compressive strength of cement after 2 and 28 days, however, only when admixture made up 0.5% and 1.0%. On the other hand, the use of nano-silica in the amount 2% had some limitations, due to its ability to agglomerate, which resulted in deterioration of the rheological and mechanical properties.

Effects of Temperature and Chemical Admixtures on the Properties of Rock-Based Geopolymers Designed for Zonal Isolation and Well Abandonment

2021 ◽  
Author(s):  
Fawzi Chamssine ◽  
Mahmoud Khalifeh ◽  
Elsayed Eid ◽  
Mona Wetrhus Minde ◽  
Arild Saasen
Keyword(s):  
Mechanical Properties ◽  
Rheological Properties ◽  
Elevated Temperatures ◽  
Setting Time ◽  
Strength Development ◽  
Fluid Loss ◽  
Rotational Viscometer ◽  
Well Abandonment ◽  
Uniaxial Compressive Strength Test ◽  
The Impact

Abstract In this paper, the impact of temperature and admixture-based salts on the mechanical and rheological properties, and composition of geopolymers was studied. Neat geopolymer and Class-G cement, manufactured by Dyckerhoff, were used as reference samples at elevated temperatures. To enhance the additive properties of the geopolymer slurry, a combination of K and Zn was examined with a variety of K:Zn ratio ranging from ∼0.15 to ∼0.25. The workability of samples was tested by using an atmospheric consistometer, while other rheological properties were examined by running fluid loss test, and rotational viscometer test. The sample with the best workability was cured for 1, 3, and 7 days at bottomhole static temperatures of 70 and 80°C and pressure of 140 MPa where the mechanical properties were examined by ultrasonic cement analyzer and uniaxial compressive strength test. X-ray diffraction was used to analyze the composition of samples at different curing times and temperatures. The obtained results showed that the salt derivative admixtures have a significant impact on the oligomerization and polycondensation phases, where it distinctively elongated the setting time, enhanced strength, and strength development. On the other hand, the temperature effect was clearly observed by reducing rheological properties, while maintaining similar mechanical properties.

Study on the Early Hydration of Cement Paste Containing Sodium Chloride

2014 ◽  
Vol 621 ◽  
pp. 35-38 ◽  
Author(s):  
Rahimah Embong ◽  
Andri Kusbiantoro
Keyword(s):  
Compressive Strength ◽  
Sodium Chloride ◽  
Cement Paste ◽  
Setting Time ◽  
Chloride Ion ◽  
Strength Development ◽  
Early Hydration ◽  
Initial Setting Time ◽  
Additive Component ◽  
Initial Setting

This paper studies the effect of sodium chloride as the additive component in cement paste. Sodium chloride was included at 0.5%, 1%, 1.5%, and 2% by weight of cement content. Analysis on the performance of this reagent was conducted via setting time, compressive strength, and porosity test. Based on the setting time analysis, the inclusion of sodium chloride can extend the initial setting time of cement paste up to 24.91% longer than control specimen. Obstruction on the formation of calcium silicate hydrate gel by sodium and chloride ion was one of the possible causes to this phenomenon. Acceleration on the compressive strength development by sodium chloride was also detected. It appears that sodium chloride was able to de-flocculate the coagulated cement particles and reduced the viscosities of cement slurries; hence resulted in faster early hydration process.

scholarly journals Glass Cullet as Additive to New Sustainable Composites Based on Alumina Binder

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3423
Author(s):  
Aleksandra Powęzka ◽  
Paweł Ogrodnik ◽  
Jacek Szulej ◽  
Mariusz Pecio
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Physical And Mechanical Properties ◽  
Recycled Aggregate ◽  
Strength Testing ◽  
Glass Cullet ◽  
Construction Engineering ◽  
Hydraulic Binder ◽  
Materials Used ◽  
The Impact

The article investigated the possibility of reusing heat resistant glass cullet to improve the mechanical properties of high-temperature composites. This is an excellent recycled aggregate that may be used as a substitute for alumina cement, and for fine natural aggregate in the production of concrete based on hydraulic binder. The experimental programme comprised of strength testing conducted on 40 × 40 × 160 mm cuboidal samples. The model mixture was modified by filler that comprised glass recyclate, amounting to 5%, 10%, and 15% of the mass of gravel and cement. Given the degree of glass grounding, use was made of two fractions, 0/4 and 0/0.125 mm. Six modified mixtures were produced. Tests were then carried out on their selected physical and mechanical properties as well as the impact of temperature, topography, and chemical composition exerted on the composite. Next, the progress and development of compressive strength and flexural strength after 14 and 28 days of curing were studied. Results showed that concrete with a 5% content of glass dust had a maximum compressive strength at the level of 85.1 MPa. Results also showed that concrete (Zk.I.5) heated at a temperature of 500 °C had a 46% higher compressive strength when compared to basic concrete (Z.I.0). The results show that it is possible to use the described components to obtain a composite that meets requirements imposed on structural materials used in construction engineering.

scholarly journals KUAT TEKAN BETON CAMPURAN GGBFS DAN FLY ASH MENGGUNAKAN RETARDER

2021 ◽  
Vol 15 (1) ◽  
pp. 51
Author(s):  
Anni Susilowati ◽  
Iqbal Yusra
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Setting Time ◽  
Physical And Mechanical Properties ◽  
Test Methods ◽  
Optimum Level ◽  
Statistical Regression ◽  
Level Of Use ◽  
Regression Test

Abstract One of the world's construction needs is casting in large volumes that require concrete with low hydration heat, and one of the problems is that the concrete has a setting during the casting queue. Therefore, a research was conducted on adding retarder to concrete with a mixture of GGBFS and Fly Ash. The purpose of this research was to analyze the physical and mechanical properties of concrete, the effect of adding retarder and obtain optimal retarder levels. This research used an experimental methods to make concrete specimens of 75% cement mix: GGBFS 15%: Fly Ash 10% with a water cement ratio of 0.5 using mix design SNI-03-2834-2000. Variations of the retarder added to the concrete mixture were 0%, 0.2%, 0.4%, and 0.6% by weight of cement with the Naptha RD 31 type. Analysis of the effect of the retarder used statistical regression test methods on SPSS. The results of research obtained the longest setting time in this researchwas 1890 minutes at a variation of 0.6% with a slump of 168 mm. The compressive strength of the concrete increased by 12.07% - 52.36% by using a retarder added material. Based on the research results, it was obtained that the optimum level of use of retarder in mixed concrete GGBFS and Fly Ash was 0.2% because it has the best physical and mechanical properties. Keywords: Fly Ash, GGBFS, Compressive Strength, Retarder

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