scholarly journals Influence of Ultrafine Natural Steatite Powder on Setting Time and Strength Development of Cement

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
K. Sudalaimani ◽  
M. Shanmugasundaram
Keyword(s):  
Compressive Strength ◽  
Setting Time ◽  
Element Distribution ◽  
Strength Development ◽  
X Ray Diffraction ◽  
Dormant Period ◽  
Initial Setting Time ◽  
Final Setting Time ◽  
Initial Setting ◽  
Cement Binder

This paper deals with the setting time and pozzolanic activity of cement when ultra fine natural steatite powder (UFNSP) is used as replacement for cement. Initial setting time, final setting time, and mortar cube strength were studied, due to the replacement of ultra fine natural steatite powder with cement at 5%, 10%, 15%, 20%, and 25% by mass of cement. The setting time of fresh cement-binder paste and compressive strength of mortar cubes are observed. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were applied to investigate the microstructural behaviour and chemical element distribution inside cement-binder matrix. Results indicate that the length of dormant period is shortened. The replacement of ultra fine natural steatite powder with cement reduces initial setting time, and final setting time and increases mortar cube compressive strength.

scholarly journals Compressive Strength and Setting Time of MTA and Portland Cement Associated with Different Radiopacifying Agents

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Mario Tanomaru-Filho ◽  
Vanessa Morales ◽  
Guilherme F. da Silva ◽  
Roberta Bosso ◽  
José M. S. N. Reis ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Zirconium Oxide ◽  
Setting Time ◽  
Strontium Carbonate ◽  
Strength Test ◽  
Initial Setting Time ◽  
Final Setting Time ◽  
Compressive Strength Test ◽  
Initial Setting

Objective. The aim of this study was to evaluate the compressive strength and setting time of MTA and Portland cement (PC) associated with bismuth oxide (BO), zirconium oxide (ZO), calcium tungstate (CT), and strontium carbonate (SC). Methods. For the compressive strength test, specimens were evaluated in an EMIC DL 2000 apparatus at 0.5 mm/min speed. For evaluation of setting time, each material was analyzed using Gilmore-type needles. The statistical analysis was performed with ANOVA and the Tukey tests, at 5% significance. Results. After 24 hours, the highest values were found for PC and PC + ZO. At 21 days, PC + BO showed the lowest compressive strength among all the groups. The initial setting time was greater for PC. The final setting time was greater for PC and PC + CT, and MTA had the lowest among the evaluated materials (P<0.05). Conclusion. The results showed that all radiopacifying agents tested may potentially be used in association with PC to replace BO.

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 Effect of Naphthalene-Based Superplasticizer and Polycarboxylic Acid Superplasticizer on the Properties of Sulfoaluminate Cement

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 662
Author(s):  
Yonghua Wu ◽  
Qiqi Li ◽  
Guoxin Li ◽  
Shiying Tang ◽  
Mengdie Niu ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Setting Time ◽  
Hydration Products ◽  
Polycarboxylic Acid ◽  
X Ray Diffraction ◽  
Calcium Sulfoaluminate Cement ◽  
X Ray ◽  
Initial Setting Time ◽  
Calcium Sulfoaluminate ◽  
Initial Setting

In order to study what the effect of superplasticizers on the setting time, fluidity and compressive strength of calcium sulfoaluminate cement (CSA) a naphthalene-based superplasticizer (BNS) and a polycarboxylic acid superplasticizer (PC) were selected to interact with CSA pastes and ye’elimite, respectively. X-ray diffraction (XRD), thermogravimetric (TG) analysis and scanning electron microscopy (SEM) analytical methods were used to investigate the class, amount and microstructure of the CSA pastes and ye’elimite pastes hydration products under the effect of the superplasticizers. The results showed that the addition of BNS can promote ettringite generation and thus improve the early compressive strength. As the addition of BNS increased from 0.8 wt% to 2.0 wt%, the initial setting time was prolonged 10 min, the final setting time was prolonged 7 min, the 5 min fluidity was improved from no fluidity to 220 mm. However, as the addition of PC increased from 0.08 wt% to 0.20 wt%, the setting time of the PC just changed within 3 min; the 5 min fluidity increased from 110 mm to 195 mm and no 15 min fluidity at all was observed. AS seen by SEM, it can be stated that generated ettringite under the addition of PC was layered and lacking bonding, and its morphology changed from rod-like to flake-like, leading to a decrease in early compressive strength.

Behavior of Cement Pastes and Mortar Containing Phosphogypsum

2015 ◽  
Vol 668 ◽  
pp. 181-188 ◽  
Author(s):  
Hanan El Nouhy ◽  
Enas Khattab ◽  
Sayieda Zeedan
Keyword(s):  
Compressive Strength ◽  
Setting Time ◽  
Blended Cement ◽  
X Ray Diffraction ◽  
Cement Pastes ◽  
Initial Setting Time ◽  
Second Stage ◽  
Setting Times ◽  
Initial Setting ◽  
Two Stages

The aim of this study is to investigate the effects of phosphogypsum on the properties of both cement pastes and mortars. Normal Portland cement CEM Ι 32,5N, Limestone Blended cement CEM ΙΙ B-L32,5N, and Slag cement CEM ΙΙ A-S32,5N were used. These cements were partially substituted by 0,2,4,6,8,10,and 15% of phosphogypsum. The test program was divided to two stages. In the first stage, tests were conducted according to BSEN 196, namely setting times (initial and final), soundness, and compressive strength (at ages 7 and 28 days). In the second stage, X-ray diffraction (XRD), and scanning electron microscope (SEM) were conducted on selected mixes from first stage. The results show that the three types of cements with the various replacement percentages of phosphogypsum met the limit of initial setting time, as well as, provided soundness of 2 mm. Also, in terms of compressive strength, it was proven, that it is possible to partially replace the three tested types of cements by phosphogypsum by up to 8%and 15% with regard to cement/sand ratio of (1:3) and (1:2) respectively.

The Influence of Alcohol Amine Admixtures on the Macroscopic Properties of Portland Cement Paste

2014 ◽  
Vol 525 ◽  
pp. 573-579
Author(s):  
Tian Yong Huang ◽  
Dong Min Wang ◽  
Ze Liu
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Portland Cement ◽  
Cement Paste ◽  
Setting Time ◽  
Initial Setting Time ◽  
Final Setting Time ◽  
Cement Mortars ◽  
Macroscopic Properties ◽  
Initial Setting

It is studied the influence of triethanolamine (TEA), diethylenetriamine (DEA), Triisopropanolamine (TIPA), aminoethyl ethanolamine (AE), and polyvinyl alcohol ammonium phosphate (PAAP) at different dosages on the properties of fresh and hardened cement pastes and mortars prepared by Portland cement, including standard consistency water, setting time, the cement paste fluidity, and compressive and flexural strength. It is showed that the high polarity alcohol amine molecules exhibit strong chemical interactions with cement matrix, which are reflected in modified macroscopic properties of the cement system. All alcohol amine admixtures increased the standard consistency water and decreased cement paste fluidity of Portland cement. TEA significantly shortened the initial setting time and final setting time of Portland cement. On the other hand, TIPA, DEA, AE and PAAP extended the initial setting time of cement but shortened the cement final setting time. All alcohol amine admixtures except TIPA at 0.2 and 0.5 dosage increased the compressive and flexural strength of the Portland cement mortars at 3 days. Especially when the dosage of PAAP is 1, the compressive strength of the Portland cement mortars at 3 days is increased 10.5MPa. All alcohol amine admixtures except AE at 0.2 and 0.5 dosage increase the compressive and flexural strength of the Portland cement mortars at 28 days, Especially when the dosage of TIPA is 1, the compressive strength of the Portland cement mortars at 28 days is increased 8.8MPa.

Performance of High-Efficiency Liquid Cement Setting Accelerator with Alkali-Free and its Acceleration Mechanism

2013 ◽  
Vol 377 ◽  
pp. 69-73
Author(s):  
Yan Wang ◽  
Jun Wang ◽  
Shu Heng Qiu ◽  
Fei Gao ◽  
Rui Gu
Keyword(s):  
Compressive Strength ◽  
High Efficiency ◽  
Bending Strength ◽  
Setting Time ◽  
X Ray Diffraction ◽  
Initial Setting Time ◽  
Acceleration Mechanism ◽  
Initial Setting ◽  
Strength Retention ◽  
Cement Setting

A kind of non-alkali high efficiency liquid cement setting accelerator named ZJ-NSA was developed by regulating the chemical composition of polymerized aluminum sulfate in this paper. The results show that the initial setting time and the final setting time are sharply shortened to 2 minutes 48 seconds and 4 minutes 37 seconds respectively, and the 1 d-aged compressive strength reach to 8.6MPa when it is mixed into P.O42.5 Portland cement with 5% addition; meanwhile, its compressive strength and bending strength retention at the age of 1d and 28d reach to 79.63%, 81.89% and 78.13%, 97.89% respectively. Phase characteristics on the hydrated cement specimens by means of x-ray diffraction (XRD) and differential scanning calorimeter (DSC) were analyzed and the acceleration mechanism was discussed.

Influence of Triethanolamine on the Properties of Cement-Based Materials

2017 ◽  
Vol 898 ◽  
pp. 2010-2017 ◽  
Author(s):  
Xiao Ying Wang ◽  
Ming Zhang Lan ◽  
Wei Fang Hou ◽  
Bin Feng Xiang ◽  
Xu Dong Zhao
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Cement Hydration ◽  
Setting Time ◽  
Cementitious Materials ◽  
Hydration Products ◽  
Initial Setting Time ◽  
Final Setting Time ◽  
Retarding Effect ◽  
Initial Setting

The effects of triethanolamine on the compressive strength and setting time of fly ash cementitious materials, slag cementitious materials, and limestone cementitious materials were investigated. The results show that the dosage of 0.04% of triethanolamine can significantly improve the 3d, 7d and 28d compressive strength of fly ash cementitious materials. It possesses less impact on the setting time. The dosage of 0.04% of triethanolamine can significantly improve the 3d and 7d compressive strength of slag cementitious materials while the effect of late strength is not obvious. It extends the initial setting time and the final setting time is not changed, which has retarding effect. The results of hydration heat and XRD show that triethanolamine extends the induction period of cement hydration, and gypsum is exhausted in advance during the hydration process. Triethanolamine promotes the transformation of AFt to AFm and there is no effect on the type of hydration products.

Development of Injectable Calcium Phosphate Cement Adding with ZrO2

2007 ◽  
Vol 361-363 ◽  
pp. 347-350
Author(s):  
J.Y. Gong ◽  
Shu Xin Qu ◽  
Q. Cui ◽  
Jie Weng
Keyword(s):  
Compressive Strength ◽  
Calcium Phosphate ◽  
Setting Time ◽  
X Ray Diffraction ◽  
Liquid Component ◽  
X Ray ◽  
Initial Setting Time ◽  
Mass Fractions ◽  
Initial Setting ◽  
Diffraction Peaks

In the present study, ZrO2 was added into the injectable calcium phosphate cements (CPCs) to improve their mechanical strength. Different mass fractions of ZrO2 (5 %, 10 %, 15 %, 20%) were mixed with the powder components consisted of tricalcium phosphate (α-TCP) and hydroxyapatite (HA). Then formed the paste via adding the liquid component consisted of citric acid. The compressive strength, the injectability, the initial setting time and finial time of CPC were measured, respectively. X-ray diffraction (XRD) was employed to analyse the phase of as-prepared CPC. Scanning Electron Microscope (SEM) and Energy dispersive spertrum (EDS) were used to observe the morphology and indicate the element components of CPC. The compressive strength of ZrO2-CPC was higher than that of CPC without added ZrO2. The compressive strength got the maximal when the mass fraction of ZrO2 was 15%. It had no effect on the injectability with adding ZrO2, which were 89 % to 92 %. It had a slight down-regulation of the initial and final setting time with adding ZrO2. SEM showed that there was amounts needle-like substance in CPC, which might be related to the improvement of compressive strength of CPC. XRD showed that there were HA, a few of α-TCP and ZrO2 diffraction peaks in CPCs. The present results indicate that it is feasible to improve the compressive strength of injectable CPC via adding ZrO2.

Study on the Properties of Ground Limestone-High Alumina Cement Gelation System

2011 ◽  
Vol 317-319 ◽  
pp. 489-497
Author(s):  
Jia Xiao ◽  
Cheng Fu Gou ◽  
Cai Yun Xu ◽  
Hao Xing ◽  
Yong Gang Jin
Keyword(s):  
Compressive Strength ◽  
Setting Time ◽  
High Alumina ◽  
Alumina Cement ◽  
Initial Setting Time ◽  
Final Setting Time ◽  
High Alumina Cement ◽  
Binder Ratio ◽  
Initial Setting ◽  
Ground Limestone

Effects of various amounts of ground limestone on the setting time, fluidity and compressive strength of high alumina cement were described in this paper. Microstructure analyses were performed by SEM. The results indicate that the initial setting time, the final setting time, the fluidity and the compressive strength of the pastes increase first and decrease later with the ground limestone content increasing, all of which reach the maximum when the ground limestone content is 3%. Meanwhile, an increase of the fineness of the ground limestone produces a shorter setting time, the fluidity of the pastes increases when the content of the ground limestone increases, and the compressive strength of the hardened pastes increases with the ground limestone content increasing and decreases with water-binder ratio increasing. The 28d strength of the pure high alumina cement paste is lower than the 3d strength, appearing the strength shrinkage, which can be improved by a proper addition of the ground limestone.

scholarly journals Experimental Study on Mechanical Properties of Repair Materials for Underwater Rapid Construction

2022 ◽  
Vol 2148 (1) ◽  
pp. 012062
Author(s):  
Shangchuan Zhao ◽  
Longlong Liu ◽  
Xindai Zuo ◽  
Shaopeng Wang
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Setting Time ◽  
Cement Concrete ◽  
Initial Setting Time ◽  
Sulphoaluminate Cement ◽  
Final Setting Time ◽  
Rapid Construction ◽  
Repair Materials ◽  
Initial Setting

Abstract Several strength grades of sulphoaluminate cement concrete were designed, and the mechanical properties with different mix ratios were studied. This paper mainly analyzes the mechanical properties of sulphoaluminate cement concrete with the setting time test, compressive strength test and flexural test. The test results show that the setting time of cement concrete can be controlled by mixing different admixtures. One hand, the initial setting time increases from 34 min to 340 min, and the final setting time increases from 57 min to 580 min when the incorporated borax content changes from 0 to 1.0 %. Other hand, the initial setting time decreased from 34 min to 11 min, and the final setting time increased from 57 min to 18 min, when the incorporated borax content changed from 0 to 0.5 %. Furthermore, the compressive strength can reach 40 MPa, and the flexural strength can reach more than 2.5MPa after 6 hours of curing. The experiment results illustrate that the setting time and the mechanical properties satisfy the needs of the rapid construction requirements under normal temperature conditions.

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