scholarly journals Effect of Delaminated MXene (Ti3C2) on the Performance of Cement Paste

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Jianping Zhu ◽  
Genshen Li ◽  
Chunhua Feng ◽  
Libo Wang ◽  
Wenyan Zhang
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Cement Paste ◽  
Cement Hydration ◽  
Hydration Heat ◽  
Hydration Process ◽  
Cement Matrix ◽  
Cement Composites ◽  
Hydrated Cement ◽  
Hydration Products

Delaminated MXene was incorporated into cement to improve the properties of cement composites, and its effects on the hydration process, microstructures, and mechanical properties were investigated, respectively. The investigation results showed that delaminated MXene was well-dispersed in the cement matrix and significantly reinforced the compressive strength of cement, especially when the addition is 0.01 wt%. Meanwhile, the total hydration heat of cement hydration and the quantity of hydration products were increased with the addition of delaminated MXene. In addition, the formation of HD C-S-H gel was promoted, and the microstructure of hydrated cement became more compact.

scholarly journals Improvement of Flexural and Compressive Strength of Cement Mortar by Graphene Nanoplatelets

2021 ◽  
Vol 15 (1) ◽  
pp. 165-171
Author(s):  
Yu Chen ◽  
Xingchen Li ◽  
Chuangchuang Li ◽  
Nana Zhang ◽  
Ronggui Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Cement Hydration ◽  
Cement Mortar ◽  
Structural Strength ◽  
Graphene Nanoplatelets ◽  
Research Trend ◽  
Cement Matrix ◽  
Cement Composites ◽  
Engineering Structures

Background: In order to provide space for improving the durability of engineering structures by enhancing strength, the addition of nanomaterials has become a research trend in recent years. Graphene and its derivatives have unique properties and have been used in certain fields, which has also stimulated continuous and in-depth research on whether it can improve structural strength. Objective: This paper investigates the mechanical properties and mechanism of cement-based materials reinforced by Graphene Nanoplatelets (GNPs). Methods: Macroscopically, the flexural strength and compressive strengths of cement mortar were tested. Microscopically, the structure and composition were characterized and analyzed by SEM, EDS, and XRD. Results: The results show that the mechanical properties of modified cement mortar are directly related to the GNPs content. When the GNPs content is 0.04wt%, the flexural and compressive strength can still be increased by 12.8% and 33.9% after 28 d. Furthermore, the appropriate content of GNPs dispersed in the cement matrix played a role in promoting cement hydration. The interconnection with hydration products further reduces cracks and pores so that the cement composites form a denser microstructure. Conclusion: The results obtained above would provide references for understanding the reinforcement mechanism of GNPs.

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%.

Mechanical Properties and Microstructure of Graphene-Cement Composites

2017 ◽  
Vol 748 ◽  
pp. 295-300 ◽  
Author(s):  
Rui Shuang Jiang ◽  
Bao Min Wang
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Compressive Strength ◽  
Cement Paste ◽  
Control Sample ◽  
Cement Composites ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Transmission Electron

In this work, two type graphene were dispersed in aqueous solution via sonication, and graphene nanoplatelets (GP) and graphene oxide (GO) were characterized by means of ultraviolet visible spectroscopy (UV-vis), X-ray diffraction (XRD) and transmission electron microscopy (TEM). In addition, the effects of different graphene (GP and GO) on mechanical properties and microstructure of cement-based materials were investigated via filed emission scanning electron microscopy (FESEM). The results suggested that the incorporation of GP and GO both improved the flexural and compressive strength of cement, and the GP had a more prominent impact on the strengths of cement, compared with GO. The flexural and compressive strength of cement increased up to 23.5% and 7.5% with 0.05 wt% GP, respectively. FESEM analysis indicated that the microstructure of GP-cement paste was similar to that of control sample without graphene, whereas, a few flower-like crystals were generated in GO-cement paste. This work could provide a new understanding for further researches of graphene-cement composites.

scholarly journals Comparative study on mechanisms for improving mechanical properties and microstructure of cement paste modified by different types of nanomaterials

2021 ◽  
Vol 10 (1) ◽  
pp. 370-384
Author(s):  
Tao Meng ◽  
Kanjun Ying ◽  
Xiufen Yang ◽  
Yongpeng Hong
Keyword(s):  
Mechanical Properties ◽  
Cement Paste ◽  
Cement Hydration ◽  
Inhibitory Effect ◽  
Test Methods ◽  
Cement Clinker ◽  
Hydration Products ◽  
Nucleation Effect ◽  
Nano Graphene ◽  
Nano Titanium Dioxide

Abstract Filling and nucleation are the mechanisms of modifying cement paste with nanomaterials, as investigated by previous studies, and are difficult to reflect the different effects of nanomaterials, especially on the changes of cement clinker and hydration products in the cement hydration process. In this study, the mechanisms of modifying cement paste with nano-calcium carbonate (NC), nano-graphene oxide (NG), nano-silica (NS), and nano-titanium dioxide (NT) were investigated by determining the mechanical properties of cement paste treated with nanomaterials and analysing the changes in the cement clinker (tricalcium silicate and dicalcium silicate), hydration products (portlandite and ettringite), and microstructure through many micro-test methods. The results indicate that the incorporation of nanomaterials could improve the early strength of cement paste specimens due to more consumption of cement clinker. Meanwhile, different nanomaterials promote the formation of different hydration products at early ages. C–A–S–H gel, flower-like ettringite, and C–S–H seeds are widely distributed in the cement paste with the incorporation of NC, NG, and NS, respectively. NT exhibits insignificant nucleation effect and has inhibitory effect on portlandite precipitation. This study provides key insights into the mechanism of nanomaterials from the perspective of cement hydration, which may promote the further research and application of nanomaterials in the cement and concrete industries.

Microstructure and Mechanism of Concrete Using Inorganic Silicate Admixture

2013 ◽  
Vol 284-287 ◽  
pp. 1235-1241
Author(s):  
Si Yu Zou ◽  
Ran Huang ◽  
An Cheng ◽  
Wei Ting Lin ◽  
Jia Liang Chang
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Porous Structure ◽  
Cement Hydration ◽  
Microscopic Analysis ◽  
Positive Influence ◽  
Composition Analysis ◽  
Hydration Products ◽  
Chemical Composition Analysis ◽  
Porosity Measurements

The study evaluates the properties of concrete mixed with inorganic silicate admixture. The admixture was used in proportions of 3%, 5%, and 7% of the weight of the cement. We performed tests on compressive strength and elastic modulus to evaluate the mechanical properties of concrete. Results show that the addition of the inorganic silicate admixture has a positive influence on the mechanical properties of concrete, with the best results obtained with 3% admixture. MIP porosity measurements determined that the addition of inorganic silicate admixture increased the density of the porous structure. SEM microscopic analysis revealed many needle-like protrusions into the porous structure of concrete. XRF chemical composition analysis indicated that these structures comprised mainly Na2O and SiO2. Can with cement hydration products Ca(OH)2 bring in Chemical reaction. Inferred pore structure Within be C-S-H gel of needle-like protruding structure. it can improve the main cause of mechanical properties of concrete.

scholarly journals Effect of MXene (Nano-Ti3C2) on Early-Age Hydration of Cement Paste

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Haibin Yin ◽  
Jianping Zhu ◽  
Xuemao Guan ◽  
Zhengpeng Yang ◽  
Yu Zhu ◽  
...  
Keyword(s):  
Cement Paste ◽  
Cement Hydration ◽  
Hydration Process ◽  
Early Age ◽  
Main Role ◽  
Hydration Products ◽  
Hydration Properties ◽  
Network Connection ◽  
The Impact ◽  
Early Age Hydration

As a new two-dimensional material, MXene (nano-Ti3C2) has been widely applied in many fields, especially for reinforced composite materials. In this paper, mechanical testing, X-ray diffraction (XRD), hydration heat, scanning electron microscope (SEM), and EDS analysis were used to analyze the impact of MXene on cement hydration properties. The obtained results revealed that (a) MXene could greatly improve the early compressive strength of cement paste with 0.04 wt% concentration, (b) the phase type of early-age hydration products has not been changed after the addition of MXene, (c) hydration exothermic rate within 72 h has small difference at different amount of MXene, and (d) morphologies of hydration products were varied with the dosage of MXene, a lot of tufted ettringites appeared in 3 d hydration products when the content of MXene was 0.04 wt%, which will have a positive effect on improving the early mechanical properties of cement paste. MXene has inhibited the Portland cement hydration process; the main role of MXene in the cement hydration process is to promote the messy ettringite becoming regular distribution at a node and form network connection structure in the crystals growth process, making the mechanics performance of cement paste significantly improved.

Study on Properties of Wollastonite Micro Fiber Reinforced Mortar

2013 ◽  
Vol 785-786 ◽  
pp. 151-156 ◽  
Author(s):  
Xiao Deng ◽  
Wen Yang ◽  
Xiao Qin Liu ◽  
Bao Jun Cheng ◽  
Tong Liu
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Glass Fiber ◽  
Comparative Studies ◽  
Cement Hydration ◽  
Three Dimensional ◽  
Sem Analysis ◽  
Fiber Content ◽  
Hydration Products ◽  
Fiber Reinforced

The paper carried out comparative studies on the workability, mechanical properties and chloride permeation resistance of wollastonite micro fiber mortar and alkali resistant glass fiber（ARGF） mortar. The results show that the mechanical properties and chloride permeation resistance of wollastonite micro fiber mortar improve significantly. The mechanical properties of wollastonite micro fiber mortar have greater advance in 90°C humidity. The SEM analysis results show that wollastonite micro fiber can form three-dimensional skeleton in the mortar, and combine closely with cement hydration products. This can make the structure of hardened paste denser and lead to excellent properties of mortar. Meanwhile, the compressive strength of wollastonite micro fiber mortar with wollastonite micro fiber content 30%(by mass) is close to ARGF mortar with ARGF content 1.5% (in volume), but the chloride permeation resistance of wollastonite micro fiber mortar is much better.

Effect of Plasticizing Admixtures on the Development of Hydration Temperatures and the Properties of Cement Pastes

2018 ◽  
Vol 761 ◽  
pp. 116-119
Author(s):  
Martin Sedlmajer ◽  
Jiri Zach ◽  
Jitka Hroudova
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Cement Hydration ◽  
Hydration Heat ◽  
Close Monitoring ◽  
Cement Pastes ◽  
Concrete Members

The hydration of cement is a very intricate process. A great amount of heat is generated during the reaction, which requires close monitoring especially in large concrete members. Modified cement pastes are simpler systems and can be easily used to observe the effect of plasticizing admixtures on the development of temperatures during cement hydration as well as its rheology and mechanical properties. Knowledge of the development of hydration temperatures can be of assistance in deliberate regulation of cement hydration and the generation of hydration heat. The paper describes what influence different amounts of different plasticizers have on the properties of cement pastes, with added focus on the development of their hydration temperatures, rheology and compressive strength.

The Development of Cement Composites Reinforced Coconut Fiber with Fly Ash Addition: Mechanical Properties and Fracture Behavior

2013 ◽  
Vol 795 ◽  
pp. 128-132
Author(s):  
Nur Izzati Muhd Nadzri ◽  
Shamsul Baharin Jamaludin ◽  
Mohd Noor Mazlee
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Fracture Behavior ◽  
Weight Ratio ◽  
Research Paper ◽  
Modulus Of Rupture ◽  
Cement Matrix ◽  
Cement Composites ◽  
Coconut Fiber

This research paper presents a study on the development of cement composites reinforced coconut fiber with fly ash addition. Various content of coconut fiber (3 wt. %, 6 wt. %, 9 wt. %, 12 wt. % and 15 wt. %) was added to the cement composites composition as reinforcement. Additions of 20 wt. % fly ash and 80 wt. % of sand were used as a mixture of cement matrix. Water to cement weight ratio ranging from 0.55 to 0.70 was used in the cement composites to maintain workability. The cement composites were then cured for 7, 14 and 28 days. The result is presented in terms of compressive strength, modulus of rupture and fracture behavior.

scholarly journals Effect of Nano-Magnesium Oxide on the Expansion Performance and Hydration Process of Cement-Based Materials

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3766
Author(s):  
Yuxun Ye ◽  
Yanming Liu ◽  
Tao Shi ◽  
Zhuojun Hu ◽  
Lei Zhong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Cement Paste ◽  
Hydration Process ◽  
Obvious Effect ◽  
Continuous Precipitation ◽  
Long Term Stability ◽  
Cement Based Materials

Many scholars are concerned about the effect of nano-MgO as an expansion agent on the performance of cement-based materials at an early age, but over a long period less attention is paid to expansion stability and mechanical properties. This article examines the influence of nano-MgO on the long-term consistency, fluidity, expansion stability, hydration, and mechanical properties of 30% fly ash cement-based materials and improves research into nano-MgO as an expansion agent. Expansion performance, flexural and compressive strength, and stability after boiling and autoclave treatment were tested for specimens mixed with a 2, 4, 6, 8 and 10% cementitious material mass of nano-MgO. X-ray diffraction (XRD) and scanning electronic microscopy (SEM) were employed to study their hydration process and microstructure. The results showed that nano-MgO had an obvious effect on the consistency, fluidity and expansion performance of cement paste. After curing in water for 365 days and autoclaving thereafter, the hydration of nano-MgO was relatively complete. The volumetric expansion pressure of the magnesium hydroxide (Mg(OH)2) crystals and the crystallization pressure generated after their continuous precipitation were the main reasons for the expansion of the slurry. Nano-MgO improved the microstructure of cement paste and significantly enhanced its long-term flexural strength and compressive strength. When the content of nano-MgO was less than 10%, the cement with 30% fly ash had good long-term stability with the potential to compensate for the shrinkage of large-volume concrete.

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