scholarly journals Use of Boron Compounds as Grinding Aids with Alcohol Amines and Their Effect on Portland Cement Setting Points

2018 ◽  
Vol 2018 ◽  
pp. 1-6
Author(s):  
Murat Çallı ◽  
Erol Pehlivan
Keyword(s):  
Portland Cement ◽  
Boric Acid ◽  
Boron Compounds ◽  
Set Point ◽  
Setting Times ◽  
Retarding Effect ◽  
Grinding Aids ◽  
Initial Setting ◽  
Cement Grinding ◽  
Cement Setting

Milling aids have been predominantly developed to increase the performance or grinding capacity of cement products, and alcohol amines have been used as grinding aids in cement grinding processes for many years. Moreover, the setting point of cement produced with grinding aids is most often changed. In this study, the effects of alkanolamines and boron compounds in different mixing amounts as grinding aids on the set point of cement were researched. Triethanolamine (TEA) and triisopropanolamine (TIPA) were used as alkanolamines and boric acid (BA) and anhydrous borax (AHB) as the boron compounds. It is evident that BA with TEA had a small effect on the cement setting point where the former decreased the retarding effect of the latter, but BA had no effect with TIPA. AHB decreased the retarding effect of TEA but had no effect with TIPA on setting times. When the boron compounds were added to TEA, they accelerated the initial setting points of cement by 15 to 20 minutes and the final setting points by 25 to 30 minutes according to the amount of TEA used.

scholarly journals The influence of Triethanol amine and ethylene glycol on the grindability, setting and hydration characteristics of Portland cement

2019 ◽  
Vol 4 (3) ◽  
pp. 81-88
Author(s):  
Fayza S Hashem ◽  
Eisa E Hekal ◽  
M Abd El Wahab
Keyword(s):  
Ethylene Glycol ◽  
Portland Cement ◽  
Water Demand ◽  
Cement Hydration ◽  
Hydration Properties ◽  
Grinding Mills ◽  
Setting Times ◽  
Grinding Aids ◽  
Triethanol Amine ◽  
Hydration Characteristics

Triethanol amine and ethylene glycol are used as grinding aids for Ordinary Portland Cement (OPC). Standard water of consistency, Blaine area, initial and final setting times and compressive strength are tested for OPC. The phase composition and microstructure of the formed hydrates are tested using DTA/TG and SEM techniques. Results showed that both the two GAs had a significant improvement in the performance of grinding mills. This is indicating by higher Blaine area when a dose of 0.03, 0.04 and 0.05wt. % are applied. Beside there are increase in the water demand (greater than 5%) for the all OPC mortar mixes admixed with triethanol amin or ethylene glycol at concentrations less than 0.05 wt.%. The improved hydration properties are reflected by an increase in the mechanical properties and microstructure of the mortar pastes admixed with the two GAs. This is with attributed to the increase in the cement fineness which leads to the progress in the degree of cement hydration.

Influence of Stearic Acid on Portland Cement Performance as Grinding Aids

2011 ◽  
Vol 374-377 ◽  
pp. 1244-1248 ◽  
Author(s):  
Hao Xin Li ◽  
Jian Sen Yang ◽  
Hong Bo Zhu
Keyword(s):  
Compressive Strength ◽  
Stearic Acid ◽  
Portland Cement ◽  
Specific Surface ◽  
Cement Paste ◽  
Heat Liberation ◽  
Hydration Heat ◽  
Grinding Aids ◽  
Cement Grinding ◽  
Production Composition

Different contents of stearic acid were added to mixtures, and the influences of stearic acid as grinding aids on portland cement performances, including specific surface, compressive strength, hydration heat, Ca(OH)2 (CH) content, C-S-H gel and ettringite (AFT) content were discussed in this paper. The results show that the addition of small amount of stearic acid is enough, and excessive addition of stearic acid is not a good matter to cement grinding. Adding a small amount of stearic acid, not only don’t improve the compressive strength, but also lower the compressive strength significantly. Although the specific surface of samples with 0.1% stearic acid is lower than that of the samples with 0.025% stearic acid and reference, the compressive strength appears of higher than others. Addition of stearic acid affects not only on the rate of heat liberation, but also the hydration heat significantly. The addition of stearic acid has uncommonly impact on the content of CH, C-S-H and AFT in cement paste at 3 days, 7days and 28 days hydration age, the samples with 0.1% stearic acid has higher content of CH, C-S-H and AFT than others, and lower conversion content of AFT from 3days to 7days and 7days to 28 days. This can explain why the cement with 0.1% stearic acid is provided with the higher compressive strength than others, from the perspective of hydration production composition.

scholarly journals Control of the setting reaction and strength development of slag-blended volcanic ash-based phosphate geopolymer with the addition of boric acid

2021 ◽  
Author(s):  
Jean Noël Yankwa Djobo ◽  
Dietmar Stephan
Keyword(s):  
Blast Furnace ◽  
Boric Acid ◽  
Blast Furnace Slag ◽  
Volcanic Ash ◽  
Strength Development ◽  
Main Process ◽  
Reaction Products ◽  
Setting Times ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

AbstractThis work aimed to evaluate the role of the addition of blast furnace slag for the formation of reaction products and the strength development of volcanic ash-based phosphate geopolymer. Volcanic ash was replaced by 4 and 6 wt% of ground granulated blast furnace slag to accelerate the reaction kinetics. Then, the influence of boric acid for controlling the setting and kinetics reactions was also evaluated. The results demonstrated that the competition between the dissolution of boric acid and volcanic ash-slag particles is the main process controlling the setting and kinetics reaction. The addition of slag has significantly accelerated the initial and final setting times, whereas the addition of boric acid was beneficial for delaying the setting times. Consequently, it also enhanced the flowability of the paste. The compressive strength increased significantly with the addition of slag, and the optimum replaced rate was 4 wt% which resulted in 28 d strength of 27 MPa. Beyond that percentage, the strength was reduced because of the flash setting of the binder which does not allow a subsequent dissolution of the particles and their precipitation. The binders formed with the addition of slag and/or boric acid are beneficial for the improvement of the water stability of the volcanic ash-based phosphate geopolymer.

Investigation of the effect of polymer‐based novel grinding aids on cement grinding efficiency

2021 ◽  
pp. 51870
Author(s):  
Ebru Dengiz Özcan ◽  
Kenan Çinku ◽  
Şenel Özdamar ◽  
Hasan Ergin ◽  
Şafak Gökhan Özkan
Keyword(s):  
Grinding Aids ◽  
Cement Grinding ◽  
Grinding Efficiency

scholarly journals In Vitro Bioactivity and Setting Times of White Portland Cement Combined with Different Radio Pacifying Agents

2017 ◽  
Vol 109 ◽  
pp. 03003 ◽  
Author(s):  
Nichola Jayne Coleman ◽  
Rajitha Hanarasinghe ◽  
Zeynep Aslı Güçlü ◽  
Samantha Ellen Booth
Keyword(s):  
Portland Cement ◽  
In Vitro Bioactivity ◽  
Setting Times ◽  
White Portland Cement

Effect of NaOH and Water Contents on Solidification of Sodium Silicate Free Geopolymer

2014 ◽  
Vol 625 ◽  
pp. 3-6 ◽  
Author(s):  
Ahmer Ali Siyal ◽  
Lukman Ismail ◽  
Zakaria Man ◽  
Khairun Azizi Azizli
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Fly Ash ◽  
Portland Cement ◽  
Sodium Hydroxide ◽  
Fourier Transform Infrared Spectroscopy ◽  
Setting Times ◽  
Behavior Study ◽  
Class F Fly Ash ◽  
Water Contents

Geopolymers are fast setting binder materials possessing strength comparable with Portland cement. In this study solidification and bonding behavior of sodium hydroxide activated class F fly ash geopolymers were determined. Solidification was determined using Vicat apparatus and bonding behavior study was carried out using Fourier transform infrared spectroscopy (FTIR). The decrease in solidification time from 105 minutes to 90 minutes was observed when Na/Al ratio increased from 1 to 1.4. By changing liquid to solid (L/S) ratio from 0.154 to 0.231 initial and final setting times found to increase. FTIR results showed main peaks at 1000 cm-1and 1432 cm-1due to asymmetric stretching of Al-O/ Si-O bonds.

scholarly journals Effect of boron-containing aggregates on setting and hardening of Portland cement mortars

2018 ◽  
Vol 163 ◽  
pp. 04003 ◽  
Author(s):  
Aneta Antolik ◽  
Michał A. Glinicki ◽  
Marek Gawlicki
Keyword(s):  
Isothermal Calorimetry ◽  
Setting Time ◽  
Radiation Shielding ◽  
Boron Compounds ◽  
Concrete Technology ◽  
Neutron Shielding ◽  
Mortar Strength ◽  
Cement Mortars ◽  
Isothermal Calorimeter ◽  
Cement Setting

Multicomponent cement-based composites are known as versatile structural materials for enhanced radiation shielding. The use of selected elements, like boron, cadmium, or rare earth elements, provides an increased neutron shielding capacity. Because of profusion, reasonable costs and large cross-section for neutron capture, boron containing minerals are suggested as aggregates for radiation shielding concrete. Despite many advantages, boron additives may act as cement setting retarders. Uncontrolled setting and hardening is not acceptable in radiation shielding concrete technology. In this work we present results from isothermal calorimetry measurements on cement mortars with boron-containing aggregates. Four types of boron aggregates were used in the studies: colemanite, ulexite, borax and boron carbide. Based on calorimetric curves, the beginning of setting time was determined. Additionally early mortar strength was investigated and linear relationship between the heat generated in the isothermal calorimeter and the early compressive strength has been observed. The use of isothermal calorimetry allowed us to estimate the limits for the content of boron compounds to be used cement mortar.

scholarly journals Influence of Lithium Carbonate on C3A Hydration

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Weiwei Han ◽  
Tao Sun ◽  
Xinping Li ◽  
Zhonghe Shui ◽  
Youzhi Chen ◽  
...  
Keyword(s):  
Pore Solution ◽  
Ph Value ◽  
Setting Time ◽  
Lithium Ion ◽  
Mineralogical Composition ◽  
Lithium Carbonate ◽  
Initial Setting Time ◽  
Initial Setting ◽  
High Alkalinity ◽  
Cement Setting

Lithium salts, known to ameliorate the effects of alkali-silica reaction, can make significant effects on cement setting. However, the mechanism of effects on cement hydration, especially the hydration of C3A which is critical for initial setting time of cement, is rarely reported. In this study, the development of pH value of pore solution, conductivity, thermodynamics, and mineralogical composition during hydration of C3A with or without Li2CO3 are investigated. The results demonstrate that Li2CO3 promotes C3A hydration through high alkalinity, due to higher activity of lithium ion than that of calcium ion in the solution and carbonation of C3A hydration products resulted from Li2CO3. Li2CO3 favors the C3A hydration in C3A-CaSO4·2H2O-Ca(OH)2-H2O hydration system and affects the mineralogical variation of the ettringite phase(s).

The Effect of Boron and its Compounds on Setting of Portland Cement

2014 ◽  
Vol 1000 ◽  
pp. 16-19 ◽  
Author(s):  
Jiří Kratochvíl ◽  
Tomáš Opravil ◽  
Pavel Diviš
Keyword(s):  
Mechanical Properties ◽  
Phase Composition ◽  
Portland Cement ◽  
Boric Acid ◽  
Cement Paste ◽  
Kinetics Of

The aim of this work is to study the influence of boron and its compounds, boric acid and borax, on the hydration of Portland cement. The samples – cement paste modified by the addition of boron, borax and boric acid in different concentrations were prepared. The results are obtained from the evaluation of calorimetric curves, mechanical properties and phase composition. The goal is to describe the kinetics of targeted retarded process of hydration and to find such addition which would suspend the setting of boron modified system entirely. The comparison of effects of each boron-containing compound is based on its concentration and on its kind.

Experimental Study on Compatibility between Alkali-Free Liquid Concrete Accelerators and Cement

2013 ◽  
Vol 438-439 ◽  
pp. 102-107 ◽  
Author(s):  
Wen Kang Guo ◽  
Li Wang ◽  
Shu Yin Wang ◽  
Dao Yin Lan ◽  
Sheng Ping Li
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Compressive Strength ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Strength Ratio ◽  
Setting Times ◽  
Gypsum Content ◽  
Durability Of Concrete

This paper selected two kinds of alkali-free liquid concrete accelerators and tested their compatibility with ordinary Portland cement, Portland cement and moderate heat Portland cement by measuring the setting times, compressive strength and compressive strength ratio of samples. The results showed that the compatibility is good between alkali-free accelerators and two types of cement: ordinary Portland cement and moderate heat Portland cement. However, the compatibility of two accelerators and Portland cement are quite different, the compatibility of AFA-2 accelerator is excellent, but AFA-1 accelerator is very poor. The setting times of alkali-free accelerators is mainly influenced by the mixing materials content, gypsum content, C3A and C3S content. In order to ensure the mechanical properties and durability of concrete, the setting times of new concrete accelerator is not the shorter the better, the appropriate initial and final setting times are 1min30s~5min and 4min~ 12min respectively.

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