Preferred Language
Articles
/
CRacDIcBVTCNdQwC5jM9
Performance evaluation of asphalt concrete mixes under varying replacement percentages of natural sand
...Show More Authors

Frequently, load associated mode of failure, rutting and fatigue, are the main failure types found in some newly constructed roads within Baghdad, the capital of Iraq, and some suburban areas. The use of excessive amount of natural sand in asphalt concrete mixes which is attractive to local contractors could be one of the possible causes to the lack of strength properties of the mixes resulting in frustration in the pavement performance. In this study, the performance properties of asphalt concrete mixes with two natural sand types, desert and river sands, were evaluated. Moreover, five replacement rates of 0, 25, 50, 75, and 100% by weight of the fine aggregate finer than 4.75 were used. The performance properties including moisture susceptibility, resilient modulus, permanent deformation, and fatigue characteristics were evaluated using indirect tensile strength, uniaxial repeated loading and repeated flexural beam tests. Also, as a part of the research objective, the laboratory tests result were used to predict the performance using VESYS computer software. Results showed that mixes with high natural sand content (NSC) are more susceptible to moisture damage and rutting, lower resilient modulus and some improvement in fatigue resistance. Based on the obtained results, the necessity has rise to revise the current local specification for asphalt concrete which specifies the limits of natural sand content in the mixes of wearing and binder courses with 25% whereas for base course mixes no limit exist yet.

Crossref
View Publication
Publication Date
Wed Dec 01 2021
Journal Name
Iraqi Journal Of Physics
Effect of Deposit Au thin Layer Between Layers of Perovskite Solar Cell on Cell's Performance
...Show More Authors

The present work aims to fabricate n-i-p forward perovskite solar cell (PSC) withئ structure (FTO/ compact TiO2/ compact TiO2/ MAPbI3 Perovskite/ hole transport layer/ Au). P3HT, CuI and Spiro-OMeTAD were used as hole transport layers. A nano film of 25 nm gold layer was deposited once between the electron transport layer and the perovskite layer, then between the hole transport layer and the perovskite layer. The performance of the forward-perovskite solar cell was studied. Also, the role of each electron transport layer and the hole transport layer in the perovskite solar cell was presented. The structural, morphological and electrical properties were studied with X-ray diffractometer, field emission s

... Show More
View Publication Preview PDF
Crossref (5)
Crossref
Publication Date
Sat Aug 31 2019
Journal Name
Iraqi Journal Of Physics
A Study of the Spectroscopic Performance of Laser Produced CdTe(x):S(1-x) Plasma
...Show More Authors

Abstract

In this work, the plasma parameters (electron temperature (Te), electron density( ne), plasma frequency (fp) and Debye length (λD)) have been studied by using the spectrometer that collect the spectrum of Laser produce CdTe(X):S(1-X) plasma at X=0.5 with different energies. The results of electron temperature for CdTe range 0.758-0.768 eV also the electron density 3.648 1018 – 4.560 1018 cm-3  have been measured under vacuum reaching 2.5 10-2 mbar .Optical properties of CdTe:S were determined through the optical transmission method using ultraviolet visible spectrophotometer within the r

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Mon Jan 01 2018
Journal Name
Journal Of Engineering And Applied Sciences
Effect of silver doping for performance of CdS solar cell prepared by thermal vacuum evaporation
...Show More Authors

Publication Date
Thu Oct 01 2015
Journal Name
Journal Of Engineering
The Effect of Recycled Heating and Cooling and The Effect of The Speciment Size on The Compressive Strength of Concrete Exposed To High Temperature
...Show More Authors

     In the present work effect of recycled heating and cooling on the values of concrete compressive strength due to high temperature of 4000C was studied.

    The tests show that the percent of reduction in compressive strength of the samples which exposed to a temperature of 4000C for one cycle was 32.5%, while the reduction was 52.7% for the samples which were exposed to recycled heating and cooling of ten times .      

   Moreover a study of the effect of specimen sizes on the percentages of compressive strength reduction due to high temperature

... Show More
View Publication Preview PDF
Publication Date
Tue Oct 30 2018
Journal Name
Journal Of Engineering
Statistical Equations to Estimate the In-situ Concrete Compressive Strength from Non-destructive Tests
...Show More Authors

The aim of this study is to propose reliable equations to estimate the in-situ concrete compressive strength from the non-destructive test. Three equations were proposed: the first equation considers the number of rebound hummer only, the second equation consider the ultrasonic pulse velocity only, and the third equation combines the number of rebound hummer and the ultrasonic pulse velocity. The proposed equations were derived from non-linear regression analysis and they were calibrated with the test results of 372 concrete specimens compiled from the literature. The performance of the proposed equations was tested by comparing their strength estimations with those of related existing equations from literature. Comparis

... Show More
View Publication Preview PDF
Crossref (5)
Crossref
Publication Date
Sun Mar 01 2015
Journal Name
Journal Of Engineering
Finite Element Investigation on Shear Lag in Composite Concrete-Steel Beams with Web Openings
...Show More Authors

In this paper, effective slab width for the composite beams is investigated with special emphasis on the effect of web openings. A three dimensional finite element analysis, by using finite element code ANSYS, is employed to investigate shear lag phenomenon and the resulting effective slab width adopted in the classical T-beam approach. According to case studies and comparison with limitations and rules stipulated by different standards and codes of practice it is found that web openings presence and panel proportion are the most critical factors affecting effective slab width, whereas concrete slab thickness and steel beam depth are less significant. The presence of web opening reduces effective slab width by about 21%.

... Show More
View Publication Preview PDF
Publication Date
Fri Nov 02 2018
Journal Name
Aci Special Publication
CFRP Repairing System at Openings in Reinforced Concrete T-Beams Cracked by Impact Loads
...Show More Authors

View Publication
Publication Date
Mon Oct 02 2023
Journal Name
Journal Of Engineering
Comparative Study between Recycled Fine and Coarse Aggregate Used in Roller Compacted Concrete Pavement
...Show More Authors

To decrease the impact on the environment of building waste, the recycled aggregate may be used in various sustainable engineering applications, such as roller compacted concrete pavement (RCCP). This research examined how using recycled aggregate as a partial replacement for natural aggregate as coarse or fine affected the mechanical properties of roller-compacted concrete pavement. The recycled aggregate was crushed and sieved to coarse and fine aggregate before being used in the roller-compacted concrete pavement. Compressive strength, splitting tensile strength, and flexural strength were all evaluated after the samples were prepared at 28 and 90 days of curing. According to the study's findings, the partial replacem

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Nov 27 2021
Journal Name
Lecture Notes In Civil Engineering
An Experimental Study on Concavely Curved Soffit Reinforced Concrete Beams Externally Bonded with FRP
...Show More Authors

View Publication
Crossref (1)
Crossref
Publication Date
Sun Oct 01 2017
Journal Name
13th International Symposium On Fiber-reinforced Polymer Reinforcement For Concrete Structures Frprcs 13
CFRP Repairing System at Openings in Reinforced Concrete T-Beams Cracked by Impact Loads
...Show More Authors