Effects of a Natural Mordenite as Pozzolan Material in the Evolution of Mortar Settings

This paper shows the results of a study focused on the evolution and properties of mortars made with a mixture of portland cement (PC) and natural mordenite (Mor). To begin, samples of mordenite, cement and sand were studied with X-ray diffraction (XRD), X-ray fluorescence (XRF) and granulometric analysis (GA). Next, mortars with a ratio of 75% PC and 25% mordenite were prepared to determine their initial and final setting times, consistency and density. Continuing, the density, weight and compressive strength of the specimens were determined at 2, 7, 28, 90 and 365 days. Finally, the specimens were studied using SEM, XRD and XRF. The results of the study of the mordenite sample showed a complex constitution where the major mineral component is mordenite, and to a lesser degree smectite (montmorillonite), halloysite, illite, mica, quartz, plagioclase and feldspar, in addition to altered volcanic glass. Tests with fresh cement/mordenite mortar (CMM) showed an initial setting time of 320 min and a final setting time of 420 min, much longer than the 212–310 min of portland cement mortar (PCM). It was established that the consistency of the cement/mordenite mortar (CMM) was greater than that of the PCM. The results of the density study showed that the CMM has a lower density than the PCM. On the other hand, the density of cement/mordenite specimens (CMS) was lower than that of portland cement specimens (PCS). The CMS compressive strength studies showed a significant increase from 18.2 MPa, at 2 days, to 72 MPa, at 365 days, with better strength than PCS at 28 and 365 days, respectively. XRD, XRF and SEM studies conducted on CMS showed a good development of primary and secondary tobermorite, the latter formed at the expense of portlandite; also, ettringite developed normally. This work proves that the partial replacement of PC by mordenite does not have a negative effect on the increase in the mechanical strength of CMS. It indicates that the presence of mordenite inhibits the spontaneous hydration of C3A and controls the anomalous formation of ettringite (Ett). All this, together with the mechanical strength reported, indicates that mordenite has a deep and positive influence on the evolution of the mortar setting and is an efficient pozzolan, meaning it can be used in the manufacture of mortars and highly resistant pozzolanic cement, with low hydration heat, low density, stability in extremely aggressive places and a low impact on the environment.

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Effect of Waste Clay Brick Powder on Physical and Mechanical Properties of Cement Paste

The Open Civil Engineering Journal ◽

10.2174/1874149502115010370 ◽

2021 ◽

Vol 15 (1) ◽

pp. 370-380

Author(s):

David Sinkhonde ◽

Richard Ocharo Onchiri ◽

Walter Odhiambo Oyawa ◽

John Nyiro Mwero

Keyword(s):

Compressive Strength ◽

Cement Paste ◽

Setting Time ◽

Partial Replacement ◽

Clay Brick ◽

X Ray ◽

Cement Replacement ◽

Clay Bricks ◽

Brick Powder ◽

Scanning Electron

Background: Investigations on the use of waste clay brick powder in concrete have been extensively conducted, but the analysis of waste clay brick powder effects on cement paste is limited. Materials and Methods: This paper discusses the effects of waste clay brick powder on cement paste. Fragmented clay bricks were grounded in the laboratory using a ball mill and incorporated into cementitious mixes as partial replacement of Ordinary Portland Cement. Workability, consistency, setting time, density and compressive strength properties of paste mixes were investigated to better understand the impact of waste clay brick powder on the cementitious paste. Four cement replacement levels of 2.5%, 5%, 7.5% and 10% were evaluated in comparison with the control paste. The chemical and mineral compositions were evaluated using X-Ray Fluorescence and X-Ray Diffractometer, respectively. The morphology of cement and waste clay brick powder was examined using a scanning electron microscope. Results: The investigation of workability exhibited a reduction of slump attributed to the significant addition of waste clay brick powder into the cementitious mixes, and it was concluded that waste clay brick powder did not significantly influence the density of the mixes. In comparison with the control paste, increased values of consistency and setting time of cement paste containing waste clay brick powder confirmed the information available in the literature. Conclusion: Although waste clay brick powder decreased the compressive strength of cement paste, 5% partial cement replacement with waste clay brick powder was established as an optimum percentage for specimens containing waste clay brick powder following curing periods of 7 and 28 days. Findings of chemical composition, mineral composition and scanning electron microscopy of waste clay brick powder demonstrated that when finely ground, fragmented clay bricks can be used in concrete as a pozzolanic material.

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Preparation of Portland Cement with Gold Ore Tailings

Advances in Materials Science and Engineering ◽

10.1155/2019/1324065 ◽

2019 ◽

Vol 2019 ◽

pp. 1-9 ◽

Cited By ~ 2

Author(s):

Qiang Wang ◽

Geng Yao ◽

Xiangnan Zhu ◽

Junxiang Wang ◽

Peng Wu ◽

...

Keyword(s):

Compressive Strength ◽

Flexural Strength ◽

Portland Cement ◽

Raw Materials ◽

Setting Time ◽

Hydration Product ◽

Difficult Problem ◽

Initial Setting Time ◽

Gold Ore ◽

Curing Age

The disposal of gold ore tailings (GTs) has been a very difficult problem for a long time. Thus, this study explored a new approach to the management of GTs by preparing Portland cement. Physical properties, reaction mechanisms, and hydration product types of cement prepared with GTs (C-GTs) and ordinary Portland cement (C-SS) were compared. X-ray diffraction (XRD), thermogravimetric (TG), and scanning electron microscope energy-dispersive spectroscopy (SEM-EDS) analysis techniques were used to study the mineralogical phases of the clinker and raw materials, hydration product types, and microtopography. The consistency, setting time, flexural strength and compressive strength values of the cement samples (C-GTs and C-SS), and burnability of the raw materials were also studied. The burnability analysis indicated that GTs provided a higher reactivity. The XRD results showed that the clinker phases of the C-GTs were C3S, C2S, C3A, and C4AF. The XRD, TG, and SEM-EDS results showed that the hydration products were flaky calcium hydroxide, rod-shaped ettringite, and granular C-S-H gels. Its compressive strength and flexural strength were, respectively, 30.4 MPa and 6.1 MPa at the curing age of 3 days and 59.1 MPa and 9.8 MPa at the curing age of 28 days, which were slightly higher than those of the C-SS. Furthermore, the results showed that the consistency, initial setting time, and final setting time for the two kinds of cement were similar, which further suggested that GTs could be used to prepare Portland cement.

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

ISRN Dentistry ◽

10.5402/2012/898051 ◽

2012 ◽

Vol 2012 ◽

pp. 1-4 ◽

Cited By ~ 5

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.

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

Materials ◽

10.3390/ma14030662 ◽

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.

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

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.525.573 ◽

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.

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EVALUATION OF WATER HYACINTH STEM ASH AS POZZOLANIC MATERIAL FOR USE IN BLENDED CEMENT

Journal of Civil Engineering Science and Technology ◽

10.33736/jcest.150.2016 ◽

2016 ◽

Vol 7 (1) ◽

pp. 1-8 ◽

Cited By ~ 2

Author(s):

Neelu Das ◽

Shashikant Singh

Keyword(s):

Compressive Strength ◽

Portland Cement ◽

Water Absorption ◽

Water Hyacinth ◽

Setting Time ◽

Blended Cement ◽

Partial Replacement ◽

Test Results ◽

Pozzolanic Material ◽

Time Specific

In this paper, the potential use of water hyacinth stem ash (WHA) in the partial replacement of cement is studied. WHA was used as a replacement for ordinary Portland cement at 10, 15, 20 and 25 wt. %. To evaluate the pozzolanic activity of WHA, the properties investigated were chemical composition, particle size, soundness, setting time, specific gravity, presence of crystalline matter, compressive strength, water absorption and sorption. Mortar cubes were tested for compressive strength up to the age of 56 days, whereas water absorption and sorption tests are carried out at the age of 28 days. Test results reveal that mortar cubes with 10% WHA substitution for Portland cement produced comparative compressive strength values to control mortar. It was also observed that the use of WHA in Portland cement has reduced water absorption characteristics.

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Development of Injectable Calcium Phosphate Cement Adding with ZrO2

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.361-363.347 ◽

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.

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EFFECT OF PARTIAL REPLACEMENT OF CEMENT WITH RICE HUSK ASH AND CELLULOSE INDUSTRIAL RESIDUE ON COMPRESSIVE STRENGTH OF CONCRETE

UMUDIKE JOURNAL OF ENGINEERING AND TECHNOLOGY ◽

10.33922/j.ujet_v5i1_1 ◽

2019 ◽

pp. 1-9

Keyword(s):

Compressive Strength ◽

Portland Cement ◽

Rice Husk ◽

Ordinary Portland Cement ◽

Rice Husk Ash ◽

Setting Time ◽

Research Work ◽

Partial Replacement ◽

Control Test ◽

Industrial Residue

In this research work, the effect of rice husk ash on concrete produced with cellulose industrial residue was studied. A mix proportion of 1:1.8:3.7 with water cement ratio of 0.47 were used. The percentage replacement of Ordinary Portland Cement (OPC) with cellulose industrial residue and rice husk ash used were 0%, 5%, 10%, 20% 30% and 40%. Concrete cubes of 150mm x 150mm x 150mm of Ordinary Portland Cement/Cellulose Industrial Residue and Ordinary Portland Cement/Cellulose Industrial Residue/Rice Ash were cast and cured at 3,7,28,60 and 90 days respectively. At the end of each hydration period, the concrete cubes were crushed and their compressive strength were determined. The result of compressive strength of 5-40% replacement of cement with cellulose industrial residue ranges from 13.02-32.81 N/mm2 as against 25.60-42.08N/mm2 for the control test. The result of the compressive strength of 5-40% replacement of cement with Cellulose Industrial Residue and Rice Husk Ash ranges from 13.17-36.30N/mm2 as against 25.60-42.08N/mm2 for the control test. The result of the initial and final setting time of Ordinary Portland Cement/Cellulose Industrial Residue and Cement/Cellulose Industrial Residue/Rice Husk Ash for 5-40% replacement of cement ranges from 61-118mins, 58-110mins and 620 – 836mins, 598 – 799mins respectively as against 52mins and 590mins for the control test. The main conclusion of this study is that the incorporation rice husk ash into cellulose industrial residue increase the strength of concrete produced. The objective of this study is to assess the strength of concrete produced when two pozzolanic materials were used to replace cement in producing concrete.

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Effect of Calcium Nitrate on the Properties of Portland–Limestone Cement-Based Concrete Cured at Low Temperature

Materials ◽

10.3390/ma14071611 ◽

2021 ◽

Vol 14 (7) ◽

pp. 1611

Author(s):

Gintautas Skripkiūnas ◽

Asta Kičaitė ◽

Harald Justnes ◽

Ina Pundienė

Keyword(s):

Compressive Strength ◽

Cement Paste ◽

Setting Time ◽

Calcium Nitrate ◽

Curing Temperature ◽

Hardened Concrete ◽

Cement Pastes ◽

Initial Setting Time ◽

Initial Setting ◽

Early Strength

The effect of calcium nitrate (CN) dosages from 0 to 3% (of cement mass) on the properties of fresh cement paste rheology and hardening processes and on the strength of hardened concrete with two types of limestone-blended composite cements (CEM II A-LL 42.5 R and 42.5 N) at different initial (two-day) curing temperatures (−10 °C to +20 °C) is presented. The rheology results showed that a CN dosage up to 1.5% works as a plasticizing admixture, while higher amounts demonstrate the effect of increasing viscosity. At higher CN content, the viscosity growth in normal early strength (N type) cement pastes is much slower than in high early strength (R type) cement pastes. For both cement-type pastes, shortening the initial and final setting times is more effective when using 3% at +5 °C and 0 °C. At these temperatures, the use of 3% CN reduces the initial setting time for high early strength paste by 7.4 and 5.4 times and for normal early strength cement paste by 3.5 and 3.4 times when compared to a CN-free cement paste. The most efficient use of CN is achieved at −5 °C for compressive strength enlargement; a 1% CN dosage ensures the compressive strength of samples at a −5 °C initial curing temperature, with high early strength cement exceeding 3.5 MPa but being less than the required 3.5 MPa in samples with normal early strength cement.

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Utilization of Circulating Fluidized Bed Combustion (CFBC) Fly Ash and Coal-Fired Fly Ash in Portland Cement

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.629-630.306 ◽

2014 ◽

Vol 629-630 ◽

pp. 306-313 ◽

Cited By ~ 1

Author(s):

Mao Chieh Chi ◽

Ran Huang ◽

Te Hsien Wu ◽

Toun Chun Fou

Keyword(s):

Fly Ash ◽

Portland Cement ◽

Fluidized Bed ◽

Building Materials ◽

Circulating Fluidized Bed ◽

Setting Time ◽

Fluidized Bed Combustion ◽

Initial Setting Time ◽

Cfbc Fly Ash ◽

Circulating Fluidized Bed Combustion

Circulating fluidized bed combustion (CFBC) fly ash is a promising admixture for construction and building materials due to its pozzolanic activity and self-cementitious property. In this study, CFBC fly ash and coal-fired fly ash were used in Portland cement to investigate the pozzolanic and cementitious characteristics of CFBC fly ash and the properties of cement-based composites. Tests show that CFBC fly ash has the potential instead of cementing materials and as an alternative of pozzolan. In fresh specimens, the initial setting time of mortars increases with the increasing amount of cement replacement by CFBC fly ash and coal-fire fly ash. In harden specimens, adding CFBC fly ash to replace OPC reduces the compressive strength. Meanwhile, CFBC fly ash would results in a higher length change when adding over 30%. Based on the results, the amount of CFBC fly ash replacement cement was recommended to be limited below 20%.

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