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 ◽  
...  

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.

2019 ◽  
Vol 11 (6) ◽  
pp. 168781401985194 ◽  
Author(s):  
Jianping Zhu ◽  
Genshen Li ◽  
Ruijie Xia ◽  
Huanhuan Hou ◽  
Haibin Yin ◽  
...  

Nanomaterial, as a new emerging material in the field of civil engineering, has been widely utilized to enhance the mechanical properties of cementitious material. Nano-SnO2 has presented high hardness characteristics, but there is little study of the application of nano-SnO2 in the cementitious materials. This study mainly investigated the hydration characteristics and strength development of Portland cement paste incorporating nano-SnO2 powders with 0%, 0.08%, and 0.20% dosage. It was found that the early-age compressive strength of cement paste could be greatly improved when nano-SnO2 was incorporated with 0.08% dosage. The hydration process and microstructure were then measured by hydraulic test machine, calorimeter, nanoindentation, X-ray diffraction, scanning electron microscope, and mercury intrusion porosimetry. It was found that the cement hydration process was promoted by the addition of nano-SnO2, and the total amount of heat released from cement hydration is also increased. In addition, the addition of nano-SnO2 can promote the generations of high density C-S-H and reduce the generations of low density C-S-H indicating the nucleation effect of nano-SnO2 in the crystal growth process. The porosity and probable pore diameter of cement paste with 0.08% nano-SnO2 were decreased, and the scanning electron microscopic results also show that the cement paste with 0.08% nano-SnO2 promotes the densification of cement microstructure, which are consistent with the strength performance.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Jianping Zhu ◽  
Genshen Li ◽  
Chunhua Feng ◽  
Libo Wang ◽  
Wenyan Zhang

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.


2021 ◽  
Vol 285 ◽  
pp. 122949
Author(s):  
Da-heng Wang ◽  
Xiao Yao ◽  
Tao Yang ◽  
Wen-rui Xiang ◽  
Ying-tao Feng ◽  
...  

2019 ◽  
Vol 116 ◽  
pp. 191-201 ◽  
Author(s):  
Mateusz Wyrzykowski ◽  
Karen Scrivener ◽  
Pietro Lura

Proceedings ◽  
2019 ◽  
Vol 34 (1) ◽  
pp. 9
Author(s):  
Joseph ◽  
Al-Bahar ◽  
Chakkamalayath ◽  
Al-Arbeed ◽  
Rasheed

One of the major concerns of concrete industries is to develop materials that consume less natural virgin resources and energy to make sustainable construction practices. Efforts have been made and even implemented to use the waste/by product materials such as fly ash, slag, silica fume, and natural pozzolana as a partial or complete replacement for Portland cement in concrete mixtures. The deterioration of concrete structures in the existing hot and cold climates of Gulf Cooperation Council countries, along with chloride and sulphate attack, demands the use of pozzolanic materials for concrete construction. Volcanic ash incorporated cement based concretes are known for its better performance in terms of strength and durability in harsh marine environments. Understanding the cement hydration process and characterizing the hydration products in microstructural level is a complex and interdependent process that allows one to design complex mix proportions to produce sustainable concrete materials. In this paper, the early and late age hydration behavior along with micro- and pore structure of cement paste samples prepared with locally available ordinary Portland cement (OPC) and volcanic ash (VA) obtained from Saudi Arabia was monitored using X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric (TGA) and N2-Adsorption analysis. The hydration progress of cement paste samples with different combinations of OPC and VA (0%, 15%, 25%, and 35%) at a w/c ratio of 0.45 after 14, 28, and 90 days were discussed. The qualitative XRD and SEM of cement paste samples showed no new phases were formed during the course of hydration. The disappearance of portlandite with increase in VA content was due to both pozzolanic effect and dilution effect. This was further confirmed quantitatively by the TGA observations that the samples with VA contain less Ca(OH)2 compared to the control specimens. N2 adsorption experiments after 90 days of curing showed larger hysteresis as the VA content increases. The studies show that the incorporation of volcanic ash certainly contributes to the generation of C-S-H and hence the cement hydration progress, especially in the later ages through pozzolanic reactions. A 15–25 % volcanic ash blended cement paste samples showed compact and denser morphological features, which will be highly detrimental for the durability performances.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Babak Fakhim ◽  
Abolfazl Hassani ◽  
Alimorad Rashidi ◽  
Parviz Ghodousi

In this study the feasibility of using the artificial neural networks modeling in predicting the effect of MWCNT on amount of cement hydration products and improving the quality of cement hydration products microstructures of cement paste was investigated. To determine the amount of cement hydration products thermogravimetric analysis was used. Two critical parameters of TGA test are PHPlossand CHloss. In order to model the TGA test results, the ANN modeling was performed on these parameters separately. In this study, 60% of data are used for model calibration and the remaining 40% are used for model verification. Based on the highest efficiency coefficient and the lowest root mean square error, the best ANN model was chosen. The results of TGA test implied that the cement hydration is enhanced in the presence of the optimum percentage (0.3 wt%) of MWCNT. Moreover, since the efficiency coefficient of the modeling results of CH and PHP loss in both the calibration and verification stages was more than 0.96, it was concluded that the ANN could be used as an accurate tool for modeling the TGA results. Another finding of this study was that the ANN prediction in higher ages was more precise.


2021 ◽  
Vol 2133 (1) ◽  
pp. 012007
Author(s):  
Zhijun Lin ◽  
Xiaofang Zhang ◽  
Zhanhua Chen ◽  
Yue Xiao ◽  
Yunhui Fang

Abstract Polycarboxylate superplasticizer is synthesised by different acid to ether ratio, which is changing the main chain structure parameters, obtained different microstructures. The effect of different microstructure PCE superplasticizer on the fluidity of cement paste, rheological thixotropy, adsorption capacity and hydration heat are studied. The results show that dispersing performance in cement with acid to ether ratio of 3.5 is the best, the molecular weight and side chain density have rather little effect on the cement hydration process.


2018 ◽  
Vol 172 ◽  
pp. 499-508 ◽  
Author(s):  
Youyuan Lu ◽  
Guiyun Shi ◽  
Yuqing Liu ◽  
Zhu Ding ◽  
Jinlong Pan ◽  
...  

Author(s):  
Mohd Azrul Andul Rajak ◽  
Zaiton Abdul Majid ◽  
Mohammad Ismail

Integration of cement-based products with nanosized-palm oil fuel ash as supplementary cementing material (SCM) amend its hydration’s degree at early age phase and the microstructural groundworks are relevant to explain the findings. Hence, the present work investigates the microstructure properties of the hardened cement paste (HCP) incorporating nPOFA to study on the effect of nPOFA in cement hydration at an early age phase. An Ordinary Portland Cement (OPC) paste as a set of HCP blended with microsized-palm oil fuel ash (mPOFA) (10-30%) and nPOFA (10-60%) were prepared and cured for 28 days. The microstructural examination of OPC, mPOFA and nPOFA cement pastes at 28 days curing age via Thermogravimetric (TG) analysis, X-Ray diffraction (XRD) analysis, morphology study and Fourier transform infrared (FTIR) spectroscopy analysis. In TG analysis, the relative weight loss of calcium hydroxide (CH) of nPOFA pastes is lower than OPC and mPOFA. Based on the CH peaks at 2?= 18.1°and 34.0° in the diffractogram, it shows that nPOFA pastes give the low CH peaks compare to OPC and mPOFA pastes. In addition, the nPOFA pastes form the dense and compact microstructure of HCP compare to other pastes. Observations from FTIR analysis, nPOFA pastes display a high frequency of Si-O band due to the high rate of pozzolanic reaction. Overall, the findings confirmed the contribution of nPOFA in accelerating the rate of cement hydration and pozzolanic reaction as it reduced the amount of CH in the cementitious matrix.


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