scholarly journals Absorption characteristics of composite ordinary portland cement (OPC)/Fe2O3/BaO X-ray shield applications

2020 ◽  
Vol 575 ◽  
pp. 012174
Author(s):  
Riswati ◽  
N Rauf ◽  
D Tahir
Keyword(s):  
Portland Cement ◽  
Ordinary Portland Cement ◽  
X Ray ◽  
Absorption Characteristics

scholarly journals Analysis of Chemical Composition of Portland Cement in Ghana: A Key to Understand the Behavior of Cement

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Mark Bediako ◽  
Eric Opoku Amankwah
Keyword(s):  
Chemical Composition ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Chemical Compositions ◽  
Test Results ◽  
Brand Name ◽  
X Ray ◽  
Portland Limestone Cement ◽  
Limestone Cement ◽  
Construction Works

The performance of Portland cement in concrete or mortar formation is very well influenced by chemical compositions among other factors. Many engineers usually have little information on the chemical compositions of cement in making decisions for the choice of commercially available Portland cement in Ghana. This work analyzed five different brands of Portland cement in Ghana, namely, Ghacem ordinary Portland cement (OPC) and Portland limestone cement (PLC), CSIR-BRRI Pozzomix, Dangote OPC, and Diamond PLC. The chemical compositions were analyzed with X-Ray Fluorescence (XRF) spectrometer. Student’st-test was used to test the significance of the variation in chemical composition between standard literature values and each of the commercial cement brands. Analysis of variance (ANOVA) was also used to establish the extent of variations between chemical compositions and brand name of the all commercial Portland cement brands. Student’st-test results showed that there were no significant differences between standard chemical composition values and that of commercial Portland cement. The ANOVA results also indicated that each brand of commercial Portland cement varies in terms of chemical composition; however, the specific brands of cement had no significant differences. The study recommended that using any brand of cement in Ghana was good for any construction works be it concrete or mortar formation.

scholarly journals Composites Based Ordinary Portland Cement and Fe2O3 for X-Ray Shield Applications

2019 ◽  
Vol 1341 ◽  
pp. 082026
Author(s):  
Riswati ◽  
I Mutmainna ◽  
N Rauf ◽  
D Tahir
Keyword(s):  
Portland Cement ◽  
Ordinary Portland Cement ◽  
X Ray

scholarly journals The Influence of Mayenite Employed as a Functional Component on Hydration Properties of Ordinary Portland Cement

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1958 ◽  
Author(s):  
Zhen He ◽  
Yang Li
Keyword(s):  
Portland Cement ◽  
Ordinary Portland Cement ◽  
X Ray Diffraction ◽  
Hydration Properties ◽  
Functional Component ◽  
X Ray ◽  
Consumption Rates ◽  
Hydrated Products ◽  
Experimental Findings ◽  
Good Agreement

Influence of C12A7 (12CaO·7Al2O3) as a functional component on hydration properties of Ordinary Portland Cement is studied using isothermal microcalorimetric technique, X-ray diffraction analysis, and thermodynamic calculation. Meanwhile, hydrate assemblages are simulated by hydrothermal software. C2AH8 (2CaO·Al2O3·8H2O) is generated as a transition phase during the hydration of pure C12A7, while formation of CAH10 (CaO·Al2O3·10H2O) is uncertain. Heat-releasing behavior of Ordinary Portland Cement (OPC) could be noticeably affected by C12A7, especially for the duration of interaction at boundary stage reduces with C12A7 replacement. Correspondingly, all hydration kinetic parameters first increase and then diminish with C12A7 replacement. Simulation results manifest in the main hydration products of OPC being ettringite, C-S-H (Calcium-Silicate-Hydrate) gel, portlandite and brucite. Increasing C12A7 replacement accelerates the consumption rates of gypsum and calcite that are typically included in OPC, and thus the ettringite content is changed and carbonate phases will be produced. Therefore, the microstructure properties of hydrated products of OPC are affected and the compressive strength is influenced. These predications are in good agreement with experimental findings. C12A7 can be used as a functional component to adjust the consumption rate of suphates in OPC, and also components of carbonate phases can be modified in hydrate assemblage.

scholarly journals Synthesis and Characterization of a Hybrid Cement Based on Fly Ash, Metakaolin and Portland Cement Clinker

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1084 ◽  
Author(s):  
Adriagni C. Barboza-Chavez ◽  
Lauren Y. Gómez-Zamorano ◽  
Jorge L. Acevedo-Dávila
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Cementitious Materials ◽  
Cement Industry ◽  
Supplementary Cementitious Materials ◽  
Cement Clinker ◽  
Dense Matrix ◽  
X Ray ◽  
Reduction Of Co2

Hybrid cement has become one of the most viable options in the reduction of CO2 emissions to the environment that are generated by the cement industry. This could be explained by the reduction of the content of clinker in the final mixture and substitution of the remaining percentage with supplementary cementitious materials with the help of an alkaline activation. Following that, properties that are provided by an Ordinary Portland Cement and of a geopolymer are mixed in this type of hybrid material and could be achieved at room temperature. Thereafter, the main objective of this research was to synthesize hybrid cements reducing the clinker content of Portland Cement up to 20% and use metakaolin and fly ash as supplementary cementitious materials in different proportions. The mixtures were alkaline activated with a mixture of sodium silicate and sodium hydroxide, calculating the amounts according to the percentage of Na2O that is present in each of the activators. The samples were then characterized using Compressive strength, X-ray diffraction, Fourier Transform Infrared Spectroscopy, and Scanning Electron Microscopy with energy-dispersive X-ray spectroscopy. The results indicated that the hybrid cements have similar mechanical properties than an Ordinary Portland Cement, and they resulted in a dense matrix of hydration products similar to those that are generated by cements and geopolymers.

The Effect of Nanoparticles of Ordinary Portland Cement (OPC) on Compressive Strength of Concrete

2014 ◽  
Vol 894 ◽  
pp. 342-348
Author(s):  
Abdoullah Namdar ◽  
Fadzil Mat Yahaya
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Construction Material ◽  
Simple Method ◽  
X Ray ◽  
Compressive Strength Of Concrete ◽  
Stability Of Structure ◽  
Scanning Electron

The quality of a construction material satisfies stability of structure. Several additives have been innovated for improve quality of compressive strength of concrete. In this paper for enhancement of compressive strength of concrete, a simple method has been proposed. The kaolin and bentonite have been treated by heat for duration of 1 hour, with constant temperature. For kaolin 200 oC, 400 oC, 600 oC, 800 oC, 1000 oC and 1200 oC of heat, and for bentonite 200 oC, 400 oC, 600 oC, 800 oC of heat has been subjected. The kaolin and bentonite treated by heat have been proposed as additive for concrete. The objective is to introduce an additive to improve compressive strength of concrete. The microstructure of modified Ordinary Portland Cement (OPC) paste has been investigated by using Field Emission Scanning Electron Microscopy (FESEM) and X-ray diffractometry (XRD). The results indicate that the best level of heat for produce additives from kaolin and bentonite, and illustrate quantity of additives for replace a portion of cement in concrete application. Modification of nanoparticles of cement paste during hydration has been discussed.

scholarly journals Effect of Limestone Addition on Physicochemical Properties of Cement: A Case Study of Laboratory Prepared Portland Cement, Sokoto Portland Cement and Dangote Portland Cement

2020 ◽  
pp. 1-10
Author(s):  
Saidu Rabiu Saidu ◽  
Danhalilu Rabiu Lawal
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Physicochemical Properties ◽  
Ordinary Portland Cement ◽  
X Ray ◽  
Setting Times

Sokoto Ordinary Portland Cement, Dangote Ordinary Portland Cement and synthesized Portland Cement were blended with various proportions of limestone. X-Ray fluorescence (XRF) studies revealed increase in CaO concentration with addition limestone in all samples studied, while the concentration of other oxide decreases. Compressive strength decreases as limestone content increases but at lower concentration (5-15%), the cured cement had appreciable strength, which also decreases with addition of limestone for all the samples. Soundness test revealed that addition of limestone within 5-15% did not cause any expansion and weakening of the cement structure. The setting times for all cement types decreases with increasing limestone addition.

Influences and Mechanisms of Ordinary Portland Cement on Properties of Asphalt Emulsion Composites

2010 ◽  
Vol 160-162 ◽  
pp. 235-240
Author(s):  
Zhen Jun Wang ◽  
Rui Wang
Keyword(s):  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Fire Hazard ◽  
Research Work ◽  
Asphalt Emulsion ◽  
Hydrated Calcium Silicate ◽  
X Ray ◽  
Splitting Strength ◽  
Marshall Stability ◽  
Hydrated Calcium

Asphalt emulsion composites are energy-saving, ecologically safe materials because they do not need any heating processes which can emit gas and fire hazard in their use. Their use for highway structural layers has attracted relatively little attention largely in China because of the problems associated with the time taken for full strength to be achieved after paving and the susceptibility to early life damage by rainfall. This research work aims at studying influences of using ordinary Portland cement to asphalt emulsion composites. The asphalt emulsion composites were prepared using a three step; road properties were studied and mechanisms were analyzed with Scanning Electron Microscope (SEM) and Energy Dispersive X-ray Analysis (EDXA). The results indicate that ordinary Portland cement addition improves road properties of the composites, such as Marshall stability, compressive strength, dynamic stability and ratio of splitting strength after freezing-thawing cycles. Splitting strength at low temperature of the composites increases with the cement increase, but if the cement dosage surpasses 3.0%, the composites become brittle. So optimal cement dosage is 3.0% in aggregate mass. There is much hydrated calcium silicate(C-S-H) gel in the composites with the cement, which can increase mass and atom percentage of Ca element and Si element, decrease proportions of free asphalt and make mastics in the composites more dense. Road properties of asphalt emulsion composites can be improved.

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