Geologic characterization of natural aggregate: A field geologist's guide to natural aggregate resource assessment

2021 ◽  
pp. 275-293
Author(s):  
W.H. Langer ◽  
D.H. Knepper
Keyword(s):  
Resource Assessment ◽  
Natural Aggregate ◽  
Aggregate Resource

scholarly journals Effects of the Variety and Content of Natural Pozzolan Coarse Aggregate on the Thermo-Mechanical Properties of Concrete

2021 ◽  
Vol 12 (4) ◽  
pp. 5405-5415
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Compressive Strength ◽  
Coarse Aggregate ◽  
The Other ◽  
Natural Pozzolan ◽  
Coarse Aggregates ◽  
Natural Aggregate ◽  
Middle Atlas

The present study investigated the effects of the variety and content of three natural pozzolan coarse aggregates on concrete. Natural pozzolan aggregates have been obtained from three volcanoes (Boutagrouine, Timahdite, and Jbel Hebri) located in the Middle Atlas region in Morocco. The three pozzolans studied were characterized, and then a comparison was made by replacing the natural aggregate with the pozzolan aggregate in the concrete in different percentages, namely 25, 50, and 100 % in volume. The results showed that the variety and content of pozzolan aggregate have a significant impact on the properties of concrete, primarily caused by the characterization of pozzolan aggregate. The density of concrete decreases with the addition of pozzolan aggregate, which decreases depending on the type of pozzolan aggregate used. The highest compressive strength was measured in the concrete specimens prepared with aggregate BP while the lowest compressive strength was noted in the concrete specimens prepared with aggregate RP. On the other hand, the substitution of NA at 100% by BP, GP, and RP aggregates leads to a decrease in the thermal conductivity of about 67%, 62%, and 55% respectively.

Characterization of organic content, brittleness index and geomechanical properties of the Eocene Cambay Shales – Insights from the Ankleshwar oil field in Western India

2020 ◽  
pp. 1-67
Author(s):  
Shib Sankar Ganguli ◽  
Souvik Sen ◽  
Sumit Verma
Keyword(s):  
Mineralogical Composition ◽  
Resource Assessment ◽  
Organic Content ◽  
Oil Field ◽  
Brittleness Index ◽  
Western India ◽  
Reservoir Properties ◽  
Geomechanical Properties ◽  
Brittle Zone

Shale resource assessment involves a detailed characterization of organic and geomechanical parameters for better insights on the reservoir properties and classifying areas of economic yield. In order to assess the Eocene Younger Cambay Shale (YCS) Group of the Ankleshwar field, western India for feasible shale resource play, we have applied a multistage screening methodology that combines estimation of organic richness, brittleness index, and geomechanical analyses. The estimated thermal maturity (Ro) and average total organic carbon (TOC) contents are within the range of 0.8-1.0 and 1.8 wt%, respectively. These estimates are comparable to the reported core-based measurements. Brittleness index (BI) based on the mineralogical composition reveals that the YCS intervals of marine origin fall into the ‘less ductile’ to ‘brittle’ zone, whereas the elastic property based estimated BI falls into the ‘less brittle’ to ‘high brittle’ zone. We established a field relationship between BI and shale volume and also deciphered the effect of TOC content on the rock elastic properties. Pore pressure in the shales is slightly above the hydrostatic gradient (10.5-11.5 MPa/km). The estimated average fracture pressure of 18.5 MPa/km, together with the BI of moderately ductile to less brittle behavior suggests that the studied shales are capable of withstanding substantial strain while hydrofracturing for effective production. We demonstrate an expedient example to characterize a potential shale unit within a producing hydrocarbon field utilizing the drilled wells with limited or no core data.

Characterization of pervious concrete with blended natural aggregate and recycled concrete aggregates

2018 ◽  
Vol 181 ◽  
pp. 155-165 ◽  
Author(s):  
Soon Poh Yap ◽  
Paul Zhao Chiat Chen ◽  
Yingxin Goh ◽  
Hussein Adebayo Ibrahim ◽  
Kim Hung Mo ◽  
...  
Keyword(s):  
Recycled Concrete ◽  
Pervious Concrete ◽  
Concrete Aggregates ◽  
Recycled Concrete Aggregates ◽  
Natural Aggregate

scholarly journals Characterization of Recycled Concrete Aggregate as Potential Replacement of Natural Aggregate in Asphalt Pavement

2019 ◽  
Vol 471 ◽  
pp. 102045 ◽  
Author(s):  
Gilberto Martinez-Arguelles ◽  
Margareth Dugarte Coll ◽  
Luis Guillermo Fuentes Pumarejo ◽  
Edgar Humberto Sanchez Cotte ◽  
Hugo Rondon ◽  
...  
Keyword(s):  
Asphalt Pavement ◽  
Recycled Concrete ◽  
Concrete Aggregate ◽  
Recycled Concrete Aggregate ◽  
Natural Aggregate

Microstructural Characterization of Concrete Prepared with Recycled Aggregates

2013 ◽  
Vol 19 (5) ◽  
pp. 1222-1230 ◽  
Author(s):  
Mafalda Guedes ◽  
Luís Evangelista ◽  
Jorge de Brito ◽  
Alberto C. Ferro
Keyword(s):  
Portland Cement ◽  
Transition Zone ◽  
Raw Materials ◽  
Microstructural Characterization ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Natural Aggregate ◽  
Normal Strength

AbstractSeveral authors have reported the workability, mechanical properties, and durability of concrete produced with construction waste replacing the natural aggregate. However, a systematic microstructural characterization of recycled aggregate concrete has not been reported. This work studies the use of fine recycled aggregate to replace fine natural aggregate in the production of concrete and reports the resulting microstructures. The used raw materials were natural aggregate, recycled aggregate obtained from a standard concrete, and Portland cement. The substitution extent was 0, 10, 50, and 100 vol%; hydration was stopped at 9, 24, and 96 h and 28 days. Microscopy was focused on the cement/aggregate interfacial transition zone, enlightening the effect of incorporating recycled aggregate on the formation and morphology of the different concrete hydration products. The results show that concretes with recycled aggregates exhibit typical microstructural features of the transition zone in normal strength concrete. Although overall porosity increases with increasing replacement, the interfacial bond is apparently stronger when recycled aggregates are used. An addition of 10 vol% results in a decrease in porosity at the interface with a corresponding increase of the material hardness. This provides an opportunity for development of increased strength Portland cement concretes using controlled amounts of concrete waste.

Morphological Characterization of Mycobacteriophage R1

1974 ◽  
Vol 32 ◽  
pp. 254-255
Author(s):  
B. L. Soloff ◽  
T. A. Rado
Keyword(s):  
Carbon Source ◽  
Stationary Phase ◽  
Growth Phase ◽  
Minimal Medium ◽  
Morphological Characterization ◽  
Logarithmic Growth Phase ◽  
Complete Lysis ◽  
Lysogenic Culture ◽  
Logarithmic Growth

Mycobacteriophage R1 was originally isolated from a lysogenic culture of M. butyricum. The virus was propagated on a leucine-requiring derivative of M. smegmatis, 607 leu−, isolated by nitrosoguanidine mutagenesis of typestrain ATCC 607. Growth was accomplished in a minimal medium containing glycerol and glucose as carbon source and enriched by the addition of 80 μg/ ml L-leucine. Bacteria in early logarithmic growth phase were infected with virus at a multiplicity of 5, and incubated with aeration for 8 hours. The partially lysed suspension was diluted 1:10 in growth medium and incubated for a further 8 hours. This permitted stationary phase cells to re-enter logarithmic growth and resulted in complete lysis of the culture.

AEM analysis of crystallization in Ti-based amorphous alloys

1983 ◽  
Vol 41 ◽  
pp. 270-271
Author(s):  
A.R. Pelton ◽  
A.F. Marshall ◽  
Y.S. Lee
Keyword(s):  
Magnetic Properties ◽  
Amorphous Alloys ◽  
Amorphous Materials ◽  
Isothermal Annealing ◽  
Amorphous Matrix ◽  
Nucleation And Growth ◽  
Current Interest ◽  
Amorphous Films ◽  
Electrical And Magnetic Properties

Amorphous materials are of current interest due to their desirable mechanical, electrical and magnetic properties. Furthermore, crystallizing amorphous alloys provides an avenue for discerning sequential and competitive phases thus allowing access to otherwise inaccessible crystalline structures. Previous studies have shown the benefits of using AEM to determine crystal structures and compositions of partially crystallized alloys. The present paper will discuss the AEM characterization of crystallized Cu-Ti and Ni-Ti amorphous films.Cu60Ti40: The amorphous alloy Cu60Ti40, when continuously heated, forms a simple intermediate, macrocrystalline phase which then transforms to the ordered, equilibrium Cu3Ti2 phase. However, contrary to what one would expect from kinetic considerations, isothermal annealing below the isochronal crystallization temperature results in direct nucleation and growth of Cu3Ti2 from the amorphous matrix.

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