scholarly journals Carbon Storage in Portland Cement Mortar: Influences of Hydration Stage, Carbonation Time and Aggregate Characteristics

2021 ◽  
Vol 3 (3) ◽  
pp. 563-580
Author(s):  
Luqman Kolawole Abidoye ◽  
Diganta B. Das
Keyword(s):  
Particle Size ◽  
Portland Cement ◽  
Carbon Storage ◽  
Cement Mortar ◽  
Fine Sand ◽  
Coarse Sand ◽  
Curing Time ◽  
Curing Conditions ◽  
Surface Areas ◽  
Ettringite Formation

This study elucidates the effects of the particle size, carbonation time, curing time and pressure on the efficiency of carbon storage in Portland cement mortar. Using pressure chamber experiments, our findings show how carbonation efficiency increases with a decrease in the particle size. Approximately 6.4% and 8.2% (w/w) carbonations were achieved in the coarse-sand and fine-sand based mortar samples, respectively. For the hydration/curing time of 7 h, up to 12% carbonation was achieved. This reduced to 8.2% at 40 h curing period. On the pressure effect, for comparable curing conditions, 2 bar at 7 h carbonation time gives 1.4% yield, and 8.2% at 5 bar. Furthermore, analysing the effect of the carbonation time, under comparable conditions, shows that 4 h of carbonation time gives up to 8.2% yield while 64 h of carbonation gives up to 18.5%. It can be reliably inferred that, under similar conditions, carbonation efficiency increases with lower-sized particles or higher-surface areas, increases with carbonation time and higher pressure but decreases with hydration/curing time. Microstructural analyses with X-ray diffraction (XRD) and scanning electron microscopy (SEM) further show the visual disappearance of calcium-silicate-hydrate (C-S-H) together with the inhibition of ettringite formation by the presence of CO2 and CaCO3 formation during carbonation.

scholarly journals Dust Particle Size and Statistical Parameters

2021 ◽  
pp. 57-93
Author(s):  
Noor Al-Dousari ◽  
Modi Ahmed ◽  
Ali Al-Dousari ◽  
Musaad Al-Daihani ◽  
Murahib Al-Elaj
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Size Distribution ◽  
Fine Sand ◽  
Coarse Sand ◽  
Optical Methods ◽  
Size Analysis ◽  
Coarse Silt ◽  
Statistical Parameters ◽  
Fine Silt

AbstractGrain ‘size’ can be specified and measured in several different ways. All methods of grain size determination have blemishes, and the choice of the most appropriate method is governed by the nature of the sample and the use to which the data are placed. Four main methods are currently used for size analysis of sands: (a) sieving; (b) settling tube analysis; (c) electro-optical methods, including Coulter Counter analysis and laser granulometry; and (d) computerized image analysis. The classification of the particle size distribution of Kuwait dust was mapped according to the parameters proposed by Folk And Ward (1957) which were widely used for quantitative comparisons between natural grain size distribution and the lognormal distribution that shows better sorted sediments have lower values of σ1. Maps of the distribution of dust in Kuwait were obtained that included: fine sand (F.S.), Coarse sand (C.S), Medium Sand (M.S), Very Fine Sane (V.F.S), Very Coarse Silt (V.C.Silt), Coarse Silt (C.Silt), Medium Silt (M.Silt), Fine Silt (F.Silt), Very Fine Silt (V.F.Silt), in addition to that, the deposition percentage of Clay, Sand, mud (silt plus clay) and silt were provided.

scholarly journals Anisotropic Shear Strength Behavior of Soil–Geogrid Interfaces

2021 ◽  
Vol 11 (23) ◽  
pp. 11387
Author(s):  
Jun Zhang ◽  
Mingchang Ji ◽  
Yafei Jia ◽  
Chenxi Miao ◽  
Cheng Wang ◽  
...  
Keyword(s):  
Particle Size ◽  
Shear Strength ◽  
Great Influence ◽  
Fine Sand ◽  
Coarse Sand ◽  
Shear Direction ◽  
Interface Shear Strength ◽  
Interface Shear ◽  
Strength Behavior ◽  
Sand And Gravel

This paper presents an experimental study on the anisotropic shear strength behavior of soil–geogrid interfaces. A new type of interface shear test device was developed, and a series of soil–geogrid interface shear tests were conducted for three different biaxial geogrids and three different triaxial geogrids under the shear directions of 0°, 45° and 90°. Clean fine sand, coarse sand, and gravel were selected as the testing materials to investigate the influence of particle size. The experimental results for the interface shear strength behavior, and the influences of shear direction and particle size are presented and discussed. The results indicate that the interface shear strength under the same normal stress varies with shear direction for all the biaxial and triaxial geogrids investigated, which shows anisotropic shear strength behavior of soil–geogrid interfaces. The soil–biaxial geogrid interfaces show stronger anisotropy than that of the soil–triaxial geogrid interfaces under different shear directions. Particle size has a great influence on the anisotropy shear strength behavior of soil–geogrid interfaces.

scholarly journals Particle Size Imbalance Index from Compositional Analysis to Evaluate Cereal Sustainability for Arid Soils in Eastern Algeria

Agriculture ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 296
Author(s):  
Siham Zaaboubi ◽  
Lotfi Khiari ◽  
Salah Abdesselam ◽  
Jacques Gallichand ◽  
Fassil Kebede ◽  
...  
Keyword(s):  
Particle Size ◽  
Management Practices ◽  
Compositional Analysis ◽  
Fine Sand ◽  
Particle Size Analysis ◽  
Coarse Sand ◽  
Richards Equation ◽  
Size Analysis ◽  
Fine Silt ◽  
Eastern Algeria

For homogeneous fertilization and crop management practices, this work hypothesized that texture could influence cereal yield, particularly in dry regions. Particle size analysis could help improve knowledge of the soil-plant relationship to obtain favorable conditions for better yield. The objective of this work is to develop a single granulometric index for durum wheat (Triticum durum) that is well correlated with yield. For this purpose, 350 independent samples of cereal soils from eastern Algeria were taken and the recorded yields were linked to these samples. The cutoff yield, which separates sub-populations with acceptable yield from those with less acceptable yield, was determined from the inflection point of the cumulative variance ratio functions related to yield by the Richards’ equation. The result obtained is 2.0 Mg.ha−1, with a theoretical critical chi-square value of 4.2, close to 4.6, which is the critical value of r2granulo as obtained by the Cate-Nelson procedure. The five-granulometric indices were found to be symmetrical around zero as follows: ±0.83 for clay (IC), ±1.73 for fine silt (IFL), ±0.31 for coarse silt (ICL), ±0.44 for fine sand (IFS), and ±1.30 for coarse sand (ICS). The two fractions that most influence the textural imbalance are fine silt (IFL) and coarse sand (ICS), with a contribution of 41% and 37%, respectively. The critical single imbalance index r g r a n u l o 2 can be used for determining cereal suitability for soils in the arid region of eastern Algeria. The lower the   r g r a n u l o 2 is, the better the soil for cereal crops.

Strength of Portland Cement with Several Composition of Bottom Ash in Different Fineness with Curing Time of 28 Days

2016 ◽  
Vol 857 ◽  
pp. 311-313
Author(s):  
Ng Hooi Jun ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Kamarudin Hussin ◽  
Soo Jin Tan ◽  
Mohd Firdaus Omar ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Compressive Strength ◽  
Portland Cement ◽  
Environmental Effects ◽  
Coal Combustion ◽  
Cement Mortar ◽  
Bottom Ash ◽  
Curing Time ◽  
Cement Replacement

Concrete is produced increasingly worldwide and accounting 10-20% emission of carbon dioxide. The potential long term opposing cost of environmental effects need to recognize. Residue of coal combustion ashes especially bottom ash will use to develop reuse application. This study focused on compressive strength of several composition of bottom ash as cement replacement in mortar. Curing of cement mortar techniques and duration also plays an important role and effects on the strength. The objective of this research is to examine the compressive strength of bottom ash in Portland cement under various compositions and fineness of bottom ash.

Fiber Concrete for 3-D Additive Technologies

2019 ◽  
Vol 974 ◽  
pp. 367-372 ◽  
Author(s):  
Sergey V. Klyuev ◽  
Andrey V. Shevchenko ◽  
E.S. Shorstova
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Fine Sand ◽  
Coarse Sand ◽  
Additive Technologies ◽  
Fine Aggregate ◽  
Cement Ratio ◽  
Fine Grained ◽  
Fiber Concrete ◽  
Concrete Placement

Fine-grained fiber concrete used in 3D printing is significantly different from conventional heavy concrete, which is determined by the increased consumption of cement, low water-cement ratio and the absence of large aggregates. The largest grain size of fine aggregate is selected taking into account the thickness of the section, the frequency and type of reinforcement, as well as the method of concrete placement. Despite the fact that the tensile strength of concrete on fine sand is more than 1.5 times higher than the strength of concrete on coarse sand, while there is a decrease in compressive strength. Due to the peculiarities of the technology of concrete manufacturing for layering, the use of coarse sands is impractical, and therefore it was decided to use quartz sand with a particle size module of 1.12 as a filler.

scholarly journals PROBABILITY OF PARTICLE-SIZE FRACTIONS OCCURRENCE IN DIFFERENT LANDFORMS

2018 ◽  
Vol 26 (4) ◽  
pp. 352-359
Author(s):  
Julião Soares de Souza Lima ◽  
Samuel Assis Silva ◽  
Daniel Pena Pereira ◽  
Marcelo Soares Altoé
Keyword(s):  
Particle Size ◽  
Clay Fraction ◽  
Spherical Model ◽  
Fine Sand ◽  
Coarse Sand ◽  
Indicator Kriging ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Probability Of Occurrence ◽  
Present Pattern

Knowing the variation of particle-size fractions, considering the relief forms, contributes for understanding the variation of other soil attributes. This work aimed to study the spatial distribution of the probability of particle-size fractions occurrence (clay, silt, very fine sand, fine sand, coarse sand, and total sand) in a clayey Oxisol with predominance of concave and convex curvatures. A sampling grid with 94 sampling points in 33x33m spacing at a depth of 0–0.20 m was built using a GPS. The spatial analysis was performed through indicator kriging. The spherical model was fit for all soil fractions, with ranges varying from 130 m to 280 m. In the region of convex curvature, the clay fraction presented the highest probability of occurrence (0.75 to 1.00), whereas in the concave region the coarse sand and total sand fractions presented the highest probability of occurrence. The very fine sand fraction and the silt did not present pattern of distribution in relation to the dominant curvatures of the relief.

scholarly journals AN INVESTIGATION ON THE USE OF BACILLUS SUBTILIS HU58 IN CEMENT MORTAR

2017 ◽  
Vol 7 (2) ◽  
pp. 1-8
Author(s):  
Nguyen Ngoc Tri Huynh ◽  
Nguyen Khanh Son
Keyword(s):  
Bacillus Subtilis ◽  
Calcium Carbonate ◽  
Portland Cement ◽  
Cement Mortar ◽  
Cement Matrix ◽  
Self Healing ◽  
Curing Time ◽  
Mortar Sample ◽  
New Type ◽  
Compressive And Flexural Strengths

Literature studies reveal the fact that incorporating bacteria into cement matrix could generate the formation of precipitated product of calcium carbonate. In this work, a new type of microorganism Bacillus subtilis HU58 was used as mixing component in formulating mortar sample of Portland cement and the effectiveness of self-healing character after 1 year of curing time was observed. Results showed the consequence in the enhancement of both compressive and flexural strengths of bacteria-modified mortar while comparing to a controlled mortar: 60MPa>56MPa (in compression) and 11MPa >9MPa (in flexion). Furthermore, those pre-existing artificial cracks 1mm in width of the prismatic mortar 40x40x160mm filled up partially (self-healing) by mineral glue.

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