scholarly journals The Suitability of Mesozoic Limestone Aggregate for Possible use as Pavement Material in Harer-Dire Dawa Area.

2021 ◽  
Author(s):  
Leta Gudissa ◽  
Tarun K. Raghuvanshi ◽  
Matebie Meten ◽  
Yadeta C. Chemeda ◽  
Ronald Schmerold
Keyword(s):  
Mechanical Properties ◽  
Specific Gravity ◽  
Physical Properties ◽  
Water Absorption ◽  
Road Construction ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Limestone Aggregate ◽  
Dire Dawa

Abstract Road construction requires a prime quality and a tremendous amount of aggregates, within which their quality is set by geological and geotechnical properties. Therefore, the Mesozoic limestone was studied in the vicinity of Harer and Dire Dawa towns, for the fundamental engineering assessments. Thirty-seven Mesozoic limestone samples obtained from the area were subjected to petrographic and geotechnical analyses to work out the suitability of the rock as a road aggregate. Physical properties were investigated using ultrasonic pulse velocity (UPV), water absorption, Na2So4 soundness, and specific gravity tests. However, the mechanical properties were determined using unconfined compressive strength (UCS), Aggregate crushing value (ACV), Aggregate Impact Value (AIV), and Los Angles Abrasion value (LAAV). The study aimed to see if the limestone aggregate complies with the globally accepted standards by employing geotechnical laboratory analyses and petrographic examination. The petrographic observations reveal the Mesozoic limestones of the area are dominantly composed of micrite, sparite, and bioclasts with subordinate intraclasts, ooids, Fe-oxides, and dolomites. Results of the physical properties show the rock has a mean UPV of 4859 m/s, a dry specific gravity of 2.64, and very low water absorption ranging from 0.2-5.7%, and Na2So4 soundness ranges from 1-14%. Among the mechanical properties, UCS, AIV, ACV, and LAAV range from 20.5-180.5Mpa, 8-20%, 24-34%, and 18.9-31.1%, respectively.Based on the aforementioned results, the limestones of the area are suitable for aggregate in road construction as they’re complying with ERA, AASHTO, ASTM, and BS standards used for pavement works.

scholarly journals Suitability Assessment of Mesozoic Limestone Aggregates as Pavement Material in Harar-Dire Dawa Area, Eastern Ethiopia

2021 ◽  
Author(s):  
Leta Gudissa ◽  
Tarun Kumar Raghuvanshi ◽  
Matebie Meten ◽  
Yadeta Chemdesa Chemeda ◽  
Ronald Schmerold
Keyword(s):  
Mechanical Properties ◽  
Specific Gravity ◽  
Physical Properties ◽  
Water Absorption ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Absorption Capacity ◽  
Eastern Ethiopia ◽  
Suitability Assessment

Abstract The quality of aggregates affects the durability and performance of pavement as it is the dominant component both in rigid and flexible pavement. Hence, aggregate quality assessment is important to ensure the good performance of aggregate in different sections of pavements. The present work aims to assess the suitability of limestone for road aggregate. Thirty-seven Mesozoic limestone samples obtained from previously identified suitable quarry sites were subjected to petrographic and geotechnical analyses. Physical properties (ultrasonic pulse velocity (PVU), water absorption (Wa), Na2SO4 soundness, and specific gravity tests) and mechanical properties (unconfined compressive strength (UCS), Aggregate crushing value (ACV), Aggregate Impact Value (AIV), and Los Angles Abrasion value (LAAV)) were determined in the lab and then compared with the globally accepted standards. The petrographic observations revealed that the Mesozoic limestones of the area are dominantly composed of micrite, sparite, and bioclasts with subordinate intraclasts, ooids, Fe-oxides, and dolomites. Results of the physical properties show the rock has a mean PVU of 4859 m/s, a bulk dry specific gravity (Gsb) of 2.64, and very low water absorption capacity ranging from 0.2-5.7%, and Na2SO4 soundness ranging from 1-14%. UCS, AIV, ACV, and LAAV range from 20.5-180.5Mpa, 8-20%, 24-34%, and 18.9-31.1%, respectively. The physical, chemical and mechanical properties of the entire limestones sample comply with the required standards, suggesting their suitability as aggregate materials in road construction.To study the interrelationships between the physical, properties of the limestone aggregate, regression analysis was applied showing a significant interrelationship between these properties.

scholarly journals Enhancing Sustainable Concrete Properties by Green Vegetable Substance

2018 ◽  
Vol 7 (4.37) ◽  
pp. 219
Author(s):  
Zainab Hasan Abdulabbas ◽  
Marwa Asad Salih ◽  
Ali Talib Jasim
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Soft Drink ◽  
Gum Arabic ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Waste Materials ◽  
Concrete Properties ◽  
Concrete Production

From several points of view, disposal of waste materials in an environment is respected to be a significant problem because of its very low biodegradability and existence in huge quantities. Waste of plastic and metal bottles caps, cans of juices and soft drink, and tires rubber being among the most pronounced. This study was conducted to evaluate the efficiency of reusing these waste materials in concrete production and solve the segregation problem. As segregation increases in concrete involving these waste materials due to lighter weight of them relative to nature aggregate, therefore, attention was intensive on using natural product (Gum Arabic) that is an environmentally friendly chemical material for improving concrete properties. The conducted tests include; compressive strength, flexural strength, splitting tensile strength, density, water absorption, and ultrasonic pulse velocity. The results showed that replacing the volume of coarse aggregate by 25% compacted bottles caps and pull-tab of cans, 20% the plastic bottle caps, and 25% tires rubber shreds used decreased the mechanical properties of concrete to some extent less than reference mix and they were enhanced by employing Gum Arabic. In addition, the employment of Gum Arabic as liquid in concrete mixes developed the mechanical properties of concrete, reduced segregation, however raised the water absorption percent and declined the density of concrete.  

scholarly journals Mechanical Properties of Na2CO3-Activated High-Volume GGBFS Cement Paste

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Taewan Kim ◽  
Yubin Jun
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
High Volume ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Strength Development ◽  
X Ray Diffraction ◽  
Granulated Blast Furnace Slag ◽  
Dry Shrinkage

The use of Na2CO3 to improve the mechanical properties of high-volume slag cement (HVSC) is experimentally investigated in this study. Ordinary Portland cement (OPC) was replaced with 50, 60, 70, 80, and 90% ground-granulated blast-furnace slag (GGBFS) by weight. Na2CO3 was added at 0, 1, 2, 3, 4, and 5 wt.% of HVSC (OPC + GGBFS). The compressive strength, water absorption, ultrasonic pulse velocity, dry shrinkage, and X-ray diffraction spectra of the Na2CO3-activated HVSC pastes were analyzed. The results indicate that Na2CO3 was effective for improving the strength of HVSC samples at both early and later ages. There was a trend of increasing HVSC sample strength with increasing Na2CO3 content. The 5% Na2CO3-activated HVSC (50% OPC + 50% GGBFS) paste had the best combination of early to later-age strength development and exhibited the highest UPV and the lowest water absorption among the Na2CO3-activated HVSC samples at later age.

Mechanical properties and freeze-thaw resistances of bronze-concrete composites

2021 ◽  
Vol 12 (2) ◽  
pp. 39
Author(s):  
Tuba Bahtli ◽  
Nesibe Sevde Ozbay
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Test Methods ◽  
Pulse Velocity ◽  
Plastic Energy ◽  
Freeze Thaw ◽  
Schmidt Rebound Hammer

Studies in the literature show that the physical and mechanical properties of concrete could be improved by the incorporation of different kinds of industrial waste, including waste tire rubber and tire steel. Recycling of waste is important for economic gain and to curb environmental problems. In this study, finely ground CuAl10Ni bronze is used to improve the physical and mechanical properties, and freeze-thaw resistances of C30 concrete. The density, cold crushing strength, 3-point bending strength, elastic modulus, toughness, and freeze-thaw resistances of concrete are determined. In addition, the Schmidt Rebound Hammer (SRH) and the ultrasonic pulse velocity (UPV) tests, which are non-destructive test methods, are applied. SEM/EDX analyses are also carried out. It is noted that a more compacted structure of concrete is achieved with the addition of bronze sawdust. Then higher density and strength values are obtained for concretes that are produced by bronze addition. In addition, concretes including bronze sawdust generally show higher toughness due to high plastic energy capacities than pure concrete.

scholarly journals A Study on Tannery Sludge as a Raw Material for Cement Mortar

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1562 ◽  
Author(s):  
Jurgita Malaiškienė ◽  
Olga Kizinievič ◽  
Viktor Kizinievič
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Cement Mortar ◽  
Ultrasonic Pulse Velocity ◽  
Xrd Analysis ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Raw Material ◽  
Tannery Sludge ◽  
Limit Values

The paper analyses the properties (chemical and mineral composition, microstructure, density, etc.) of recycled tannery sludge (TS) and the possibilities for using it in cement mortar mixture. Mortar specimens containing 3–12% of tannery sludge by weight of cement and 3–9% of tannery sludge by weight of sand were tested. Flowability, density, ultrasonic pulse velocity (UPV), flexural and compressive strength, water absorption and sorptivity of the mortar were analysed. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis of tannery sludge and mortar are presented. The tests revealed that replacement of 6% of cement with tannery sludge in the mix increased flexural and compressive strength and UPV values, whereas water absorption decreased. SEM and XRD analysis revealed that specimens with tannery sludge contained lower amounts of ettringite and higher amounts of portlandite; the obtained structure was denser and contained more calcium hydrosilicates (C-S-H). Chromium leaching values in cement mortars were found not to exceed the limit values set forth in Directive 2003/33/EC.

Ultrasonic pulse velocity for the evaluation of physical and mechanical properties of a highly porous building limestone

Ultrasonics ◽  
2015 ◽  
Vol 60 ◽  
pp. 33-40 ◽  
Author(s):  
Emilia Vasanelli ◽  
Donato Colangiuli ◽  
Angela Calia ◽  
Maria Sileo ◽  
Maria Antonietta Aiello
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Highly Porous
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