Numerical investigation on redundancy of bridges with AASHTO I-girders

2021 ◽  
Vol 17 (1-2) ◽  
pp. 41-50
Author(s):  
Emran Alotaibi ◽  
Nadia Nassif ◽  
Mohamad Alhalabi ◽  
Humam Al Sebai ◽  
Samer Barakat
Keyword(s):  
Compressive Strength ◽  
Numerical Investigation ◽  
The Other ◽  
Original Design ◽  
High Importance ◽  
Strength Variation ◽  
Girder Bridges ◽  
Bridge Safety ◽  
Unbonded Tendons ◽  
Aashto Lrfd

Bridge safety is one of the most critical concerns among civil engineering fields due to its high importance. The redundancy of bridges was heavily investigated in the literature; however, they were focused on twin girder redundancy cases. Additionally, literatures were scarce in studies that focused on the improvement that should be made to achieve redundancy systems in different AASHTO I-girder types. Thus, this study focused on assessing the additional required number of tendons for different AASHTO I-girder types and spacing between them to achieve the redundancy of I-girder bridges. The additional unbonded tendons are suggested to be added externally or internally. The parameters varied in this study are compressive strength of ultrahigh-performance concrete (UHPC), spacing between girders (i.e. number of girders) and type of girders. Leap Bridge Concrete software was used to simulate the required structural modes. After performing extensive numerical analyses following AASHTO LRFD guidelines, the results have shown that in case of the removal of external I-girder, the tendons in the nearest girder need to be nearly increased by 1.85 to 2.3 times compared to the original design, depending on spacing, compressive strength, and the number of girders. On the other hand, in the case of interior girder removal, the number of tendons in the nearest two girders need to be increased by 1.24 to 1.32 times the original design. The effect of compressive strength variation of the used UHPC was negligible compared to spacing and type of girder. It is worth mentioning that all simulations in this study were verified using CSI Bridge software.

HAYNES STELLITE ALLOY No. 98M2

Alloy Digest ◽  
1960 ◽  
Vol 9 (7) ◽  
Keyword(s):  
Fracture Toughness ◽  
Compressive Strength ◽  
Physical Properties ◽  
Room Temperature ◽  
Base Alloy ◽  
Heat Treating ◽  
The Other ◽  
Stellite Alloy ◽  
Cobalt Base Alloy ◽  
Cobalt Base

Abstract HAYNES STELLITE 98M2 Alloy is a cobalt-base alloy having higher compressive strength and higher hardness than all the other cobalt-base alloys at room temperature and in the red heat range. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive strength as well as fracture toughness. It also includes information on heat treating, machining, and joining. Filing Code: Co-22. Producer or source: Haynes Stellite Company.

scholarly journals Effect of Copper Addition on the AlCoCrFeNi High Entropy Alloys Properties via the Electroless Plating and Powder Metallurgy Technique

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 540
Author(s):  
Mohamed Ali Hassan ◽  
Hossam M. Yehia ◽  
Ahmed S. A. Mohamed ◽  
Ahmed Essa El-Nikhaily ◽  
Omayma A. Elkady
Keyword(s):  
Compressive Strength ◽  
Powder Metallurgy ◽  
Atomic Radius ◽  
The Other ◽  
High Entropy Alloy ◽  
Coating Process ◽  
High Entropy Alloys ◽  
Powder Metallurgy Technique ◽  
Copper Metal ◽  
High Entropy

To improve the AlCoCrFeNi high entropy alloys’ (HEAs’) toughness, it was coated with different amounts of Cu then fabricated by the powder metallurgy technique. Mechanical alloying of equiatomic AlCoCrFeNi HEAs for 25 h preceded the coating process. The established powder samples were sintered at different temperatures in a vacuum furnace. The HEAs samples sintered at 950˚C exhibit the highest relative density. The AlCoCrFeNi HEAs model sample was not successfully produced by the applied method due to the low melting point of aluminum. The Al element’s problem disappeared due to encapsulating it with a copper layer during the coating process. Because the atomic radius of the copper metal (0.1278 nm) is less than the atomic radius of the aluminum metal (0.1431 nm) and nearly equal to the rest of the other elements (Co, Cr, Fe, and Ni), the crystal size powder and fabricated samples decreased by increasing the content of the Cu wt%. On the other hand, the lattice strain increased. The microstructure revealed that the complete diffusion between the different elements to form high entropy alloy material was not achieved. A dramatic decrease in the produced samples’ hardness was observed where it decreased from 403 HV at 5 wt% Cu to 191 HV at 20 wt% Cu. On the contrary, the compressive strength increased from 400.034 MPa at 5 wt% Cu to 599.527 MPa at 15 wt% Cu with a 49.86% increment. This increment in the compressive strength may be due to precipitating the copper metal on the particles’ surface in the nano-size, reducing the dislocations’ motion, increasing the stiffness of produced materials. The formability and toughness of the fabricated materials improved by increasing the copper’s content. The thermal expansion has increased gradually by increasing the Cu wt%.

scholarly journals Effect of Fly Ash on Compressive Strength, Drying Shrinkage, and Carbonation Depth of Mortar with Ferronickel-Slag Powder

2021 ◽  
Vol 11 (3) ◽  
pp. 1037
Author(s):  
Se-Jin Choi ◽  
Ji-Hwan Kim ◽  
Sung-Ho Bae ◽  
Tae-Gue Oh
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Construction Industry ◽  
Bituminous Coal ◽  
Raw Materials ◽  
Drying Shrinkage ◽  
The Other ◽  
Test Results ◽  
Slag Powder ◽  
Ferronickel Slag

In recent years, efforts to reduce greenhouse gas emissions have continued worldwide. In the construction industry, a large amount of CO2 is generated during the production of Portland cement, and various studies are being conducted to reduce the amount of cement and enable the use of cement substitutes. Ferronickel slag is a by-product generated by melting materials such as nickel ore and bituminous coal, which are used as raw materials to produce ferronickel at high temperatures. In this study, we investigated the fluidity, microhydration heat, compressive strength, drying shrinkage, and carbonation characteristics of a ternary cement mortar including ferronickel-slag powder and fly ash. According to the test results, the microhydration heat of the FA20FN00 sample was slightly higher than that of the FA00FN20 sample. The 28-day compressive strength of the FA20FN00 mix was approximately 39.6 MPa, which was higher than that of the other samples, whereas the compressive strength of the FA05FN15 mix including 15% of ferronickel-slag powder was approximately 11.6% lower than that of the FA20FN00 mix. The drying shrinkage of the FA20FN00 sample without ferronickel-slag powder was the highest after 56 days, whereas the FA00FN20 sample without fly ash showed the lowest shrinkage compared to the other mixes.

Effect of strain rate, off-axis loading and high-velocity impact damage on the compressive strength of C/SiC composite

2018 ◽  
Vol 53 (4) ◽  
pp. 535-546 ◽  
Author(s):  
M Altaf ◽  
S Singh ◽  
VV Bhanu Prasad ◽  
Manish Patel
Keyword(s):  
Compressive Strength ◽  
Strain Rate ◽  
High Velocity ◽  
Impact Damage ◽  
The Other ◽  
High Velocity Impact ◽  
Fibre Bundles ◽  
Velocity Impact ◽  
Kink Bands ◽  
Other Hand

The compressive strength of C/SiC composite at different strain rates, off-axis orientations and after high-velocity impact was studied. The compressive strength was found to be 137 ± 23, 130 ± 46 and 162 ± 33 MPa at a strain rate of 3.3 × 10−5, 3.3 × 10−3, 3.3 × 10−3 s−1, respectively. On the other hand, the compressive strength was found to be 130 ± 46, 99 ± 23 and 87 ± 9 MPa for 0°/90°, 30°/60° and 45°/45° fibre orientations to loading direction, respectively. After high-velocity impact, the residual compressive strength of C/SiC composite was found to be 58 ± 26, 44 ± 18 and 36 ± 3.5 MPa after impact with 100, 150 and 190 m/s, respectively. The formation of kink bands in fibre bundles was found to be dominant micro-mechanism for compressive failure of C/SiC composite for 0°/90° orientation. On the other hand, delamination and the fibre bundles rotation were found to be the dominant mechanism for off-axis failure of composite.

The Effect of Sand/Cement Ratio and Cement Grade on the Compressive Strength of Foam Concrete

2013 ◽  
Vol 405-408 ◽  
pp. 2933-2937
Author(s):  
Ji Chuan Geng ◽  
Kun Ni ◽  
Shan Qi Fang ◽  
Yun Xing Shi ◽  
Yi Ning Ding ◽  
...  
Keyword(s):  
Compressive Strength ◽  
The Other ◽  
Foam Concrete ◽  
Cement Ratio ◽  
Series Of Experiments

A series of experiments have been undertaken to investigate the effects, on compressive strength, of variable sand/cement ratios and cement grade. Ten mixtures of different s/c ratios used two kinds of cement were cast and the compressive strength at different curing ages was tested. The results indicate that the compressive strength gets lower as the s/c ratio increases for both 42.5R and 32.5R cement. For the mixtures used 32.5R cement, the 28-day compressive strength is pretty low for the s/c ratios of 1.5 and 2. The specimens used 42.5R cement have higher compressive strength than those with 32.5R cement. The compressive strength decreases from 42.5R to 32.5R cement are significantly smaller for the s/c ratios of 0.5 and 1 than the other three s/c ratios.

scholarly journals Sulphate Resistance of Boron Active Belite Cement Concrete

2020 ◽  
Vol 1 (1) ◽  
pp. 11-15 ◽  
Author(s):  
Abdulkadir Cüneyt AYDIN
Keyword(s):  
Compressive Strength ◽  
Ultrasonic Velocity ◽  
The Other ◽  
Weight Increase ◽  
Chemical Effect ◽  
Unit Weight ◽  
Control Group ◽  
Cement Concrete ◽  
Ultrasound Measurements ◽  
Belite Cement

The sulphate resistance of variable concretes, including Boron active belite cement (BABC), CEM I 42.5 R and CEM II 32.5 B-S cements, were determined in the present study. The compressive strength, ultrasonic velocity, Schmidt, and unit weight tests were applied to steam cured and water cured samples. Three Na2SO4 solutions of %5, %10 and %20 were prepared for each type of concrete except for the control group and the samples were exposed to the effect of sulphate solutions for 24 weeks. As a result, weight increase was determined in CEM I 42.5 R cement samples the least, and in BAB cement samples the most. As expected, pronounced chemical effect was not observed in samples of cement CEM II.32.5 B-S. On the other hand, while decreases or slight increases were observed in the ultrasound measurements of CEM I 42.5 R cement samples after sulphate test, critical increases were observed in BAB and CEM II 32.5 B-S cement samples. Under sulphate effect, water and steam cures had explicit effects on pressure resistances.

scholarly journals The possibility of obtaining beta-anhydrite from waste nitrogypsum

2004 ◽  
Vol 40 (1) ◽  
pp. 89-100 ◽  
Author(s):  
S. Marinkovic ◽  
A. Kostic-Pulek ◽  
S. Popov ◽  
J. Djinovic ◽  
Prvoslav Trifunovic
Keyword(s):  
Compressive Strength ◽  
Crystal Growth ◽  
Compression Strength ◽  
The Other ◽  
Solid Ratio ◽  
Double Salts ◽  
Ir Analysis

The possibility of obtaining ? - anhydrite from nitrogypsum, which is waste from a nitrocellulose plant, was investigated. It was shown by means of qualitative IR analysis that the product obtained by heating nitrogypsum for 5 hours at 700 o C was ? - anhydrite. When the ?- anhydrite was mixed with water at a W/S (water/solid) ratio of 0.54 in presence of different accelerators (CaO, mixture CaO - ash, ash, Na2SO4 and K2SO4), pastes were formed which hardened on standing. The compressive strength of the hardened samples was measured after 7 and 28 days and their composition determined by qualitative IR analysis. On the basis of these results, it was observed that a relationship exists between the composition (depending on the used accelerator) and the compression strength of the samples. Namely, the formation of large cores of double salts: syngenite (K2SO4 ?CaSO4 ?H2O) and glauberite (Na2SO4 ?CaSO4), in the presence of the accelerators K2SO4 and Na2SO4, respectively, was due to the rapid and complete crystallization of the dihydrate (CaSO4 ?2H2O). This fast crystal growth of the dihydrate resulted in high compressive strengths of these samples. In the other samples (prepared in presence of the accelerators: CaO, mixture CaO - ash and ash), dihydrate did not form and, consequently, their compressive strength was low.

The Effect of Different Curing Conditions on Compressive Strength of Concrete

2017 ◽  
Vol 60 (3) ◽  
pp. 147-153
Author(s):  
Muhammad Arslan ◽  
Muhammad Asif Saleem ◽  
Maria Yaqub ◽  
Muhammad Saleem Khan
Keyword(s):  
Compressive Strength ◽  
Research Work ◽  
Concrete Structures ◽  
Strength Test ◽  
The Other ◽  
Cylindrical Shape ◽  
Curing Conditions ◽  
Compressive Strength Test ◽  
Different Types ◽  
Compressive Strength Of Concrete

The focus of this research work was to analyse the effect of different types of curing oncompressive strength of concrete structures. For this purpose, 54 test specimens of cylindrical shape wereprepared. These specimens were cured with different methods and were tested on different age days toanalyse the effect of curing on compressive strength. Test specimens cured with conventional water curingmethod gives the highest results as compared to the other adopted methods.

Effects of 0-30% Wood Ashes as a Substitute of Cement on the Strength of Concretes

2022 ◽  
Author(s):  
Theodore Gautier Bikoko ◽  
Jean Claude Tchamba ◽  
Valentine Yato Katte ◽  
Divine Kum Deh
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Greenhouse Gases ◽  
Negative Influence ◽  
Wood Ash ◽  
The Other ◽  
Other Hand ◽  
Strength Tests ◽  
Compressive Strength Of Concrete ◽  
Curing Age

To fight against the high cost and the increasing scarcity of cement and at the same time to reduce the CO2 greenhouse gases emission associated with the production of Portland cement, two types of wood ashes as a substitute of cement in the production of concretes were investigated. In this paper, we substituted cement by two types of species of wood ashes namely, avocado and eucalyptus ashes following the proportions ranging from 0% to 30 % on one hand, and on the other hand, we added these two types of species of wood ashes namely, avocado and eucalyptus ashes following the proportions ranging from 0% to 10 % by weight of cement in the concrete samples. After 7, 14 and 28 days of curing, compressive strength tests were conducted on these concrete samples. The findings revealed that using wood ashes as additives/admixtures or as a substitute of cement in the production/manufacturing of concrete decreased the compressive strength of concrete. Hence, it can be said that wood ash has a negative influence on the strength of concrete. At three percent (3%) and ten percent (10%) of addition, the wood ash from eucalyptus specie offers better resistance compared to the wood ash from avocado specie, whereas at five percent (5%) of addition, the wood ash from avocado specie offers better resistance compared to the wood ash from eucalyptus specie. At thirty percent (30%) of substitution, the wood ash from eucalyptus specie offers better resistance compared to the wood ash from avocado specie. The compressive strengths increase with the increase of curing age.

Sign in / Sign up

Export Citation Format

Share Document