Preferred Language
Articles
/
joe-454
Retrofitting of Reinforced Concrete Damaged Short Column Exposed to High Temperature
...Show More Authors

Experimental research was carried out to investigate the performance of CFRP wrapping jackets used for retrofitting twelve square reinforced concrete (CR) column specimens damaged by exposure to fire flame, at different temperatures of  300, 500 and 700ºC, except for two specimens that were not burned. The specimens were then loaded axially till failure after gradual or sudden cooling. The specimens were divided into two groups containing two main reinforcement ratios, ρ= 0.0314 and ρ= 0.0542. This was followed by the retrofitting procedure that included wrapping all the specimens with two layers of CFRP fabric sheets. The test results of the retrofitted specimens showed that the fire damaged RC column specimens can be retrofitted efficiently by using CFRP wrap jackets, as they provided good confinement of the damaged concrete core. Also, the ultimate load capacity of each retrofitted specimen was increased compared to that before retrofitting by about 16, 34 and 44% for the  specimens burned at 300, 500 and 700ºC respectively, and cooled gradually, whereas this increase was 44% and 111% for the specimens subjected to burning temperatures of 500 and 700ºC, respectively, but cooled suddenly. This ability of each column specimen to absorb energy before and after retrofitting was also improved. The average improvement in modulus of toughness before and after retrofitting was 8% for the specimens not exposed to fire flame and 10, 100, 250% for the specimens exposed to 300, 500 and 700ºC respectively.

 

View Publication Preview PDF
Quick Preview PDF
Publication Date
Sat Jan 01 2022
Journal Name
Journal Of The Mechanical Behavior Of Materials
Concrete strength development by using magnetized water in normal and self-compacted concrete
...Show More Authors
Abstract<p>The main objective of this work was to adopt an environmentally friendly technology with enhanced results. The technology of magnetic water (MW) treatment system can be used in concrete mixture production instead of potable water (PW) to improve both workability and strength. Two types of concrete were adopted: normal concreter production with two grades 25 and 35 MPa and the self-compacted concrete (SCC) with 35 MPa grade. The concrete mixes containing MW instead of PW results showed that, for 25 MPa grade, an improvement in a compressive strength of 15.1, 14.8, and 10.2% was achieved for 7, 28, and 90 days, respectively. For 35 MPa grade, an improvement of 13.6, 11.5, and </p> ... Show More
Crossref (7)
Crossref
Publication Date
Sat Jan 01 2022
Journal Name
Journal Of The Mechanical Behavior Of Materials
Concrete strength development by using magnetized water in normal and self-compacted concrete
...Show More Authors
Abstract<p>The main objective of this work was to adopt an environmentally friendly technology with enhanced results. The technology of magnetic water (MW) treatment system can be used in concrete mixture production instead of potable water (PW) to improve both workability and strength. Two types of concrete were adopted: normal concreter production with two grades 25 and 35 MPa and the self-compacted concrete (SCC) with 35 MPa grade. The concrete mixes containing MW instead of PW results showed that, for 25 MPa grade, an improvement in a compressive strength of 15.1, 14.8, and 10.2% was achieved for 7, 28, and 90 days, respectively. For 35 MPa grade, an improvement of 13.6, 11.5, and </p> ... Show More
View Publication
Scopus (9)
Crossref (7)
Scopus Clarivate Crossref
Publication Date
Tue Apr 01 2025
Journal Name
Civil Engineering Journal
Flexural Behavior of Hybrid Fiber Reinforced SCC Beams with Longitudinal and Bubble Voids
...Show More Authors

To investigate the flexural behavior of self-consolidating hybrid fiber-reinforced concrete beams containing voids experimentally, six RC beams were tested, one solid without fiber and the others containing hooked-steel and macro-polypropylene fibers with a volume fraction of 1 and 0.5%, respectively. One of the five fibrous beams was solid; two contain a series of recycled plastic balls of diameters 110 and 120 mm, and another two contain a single longitudinal circular void created by PVC pipes of diameters 90 and 110 mm. The flexural behavior of the beams was assessed depending on the load-deflection curve, load-strain curve, ductility, toughness, stiffness, and crack patterns. The experimental outcomes showed that all the tested

... Show More
View Publication Preview PDF
Scopus Crossref
Publication Date
Fri Sep 01 2006
Journal Name
Journal Of Engineering
Effect of Transverse Base Width Restraint on the Cracking Behavior of Massive Concrete
...Show More Authors

The effect of considering the third dimension in mass concrete members on its cracking behavior is investigated in this study. The investigation includes thermal and structural analyses of mass concrete structures. From thermal analysis, the actual temperature distribution throughout the mass concrete body was obtained due to the generation of heat as a result of cement hydration in addition to the ambient circumstances. This was performed via solving the differential equations of heat conduction and convection using the finite element method. The finite element method was also implemented in the structural analysis adopting the concept of initial strain problem. Drying shrinkage volume changes were calculated using the procedure suggested

... Show More
Publication Date
Sat Jul 22 2023
Journal Name
Journal Of Engineering
Effect of Transverse Base Width Restraint on the Cracking Behavior of Massive Concrete
...Show More Authors

The effect of considering the third dimension in mass concrete members on its cracking behavior is investigated in this study. The investigation includes thermal and structural analyses of mass concrete structures. From thermal analysis, the actual temperature distribution throughout the mass concrete body was obtained due to the generation of heat as a result of cement hydration in
addition to the ambient circumstances. This was performed via solving the differential equations of heat conduction and convection using the finite element method. The finite element method was also implemented in the structural analysis adopting the concept of initial strain problem. Drying shrinkage volume changes were calculated using the procedure sug

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Wed May 17 2023
Journal Name
Journal Of Engineering
Effect of Metakaolin on Properties of Lightweight Porcelinate Aggregate Concrete
...Show More Authors

Research in Iraq has expanded in the field of material technology involving the properties of the lightweight concrete using natural aggregate. The use of the porcelinate aggregate in the production of structural light concrete has a wide objective
and requires a lot of research to become suitable for practical application. In this work metakaolin was used to improve compressive strength of lightweight porcelinate concrete which usually have a low compressive strength about 17 MPa . The effect of metakaolin on compressive, splitting tensile, flexure strengths and modulus of elasticity of lightweight porcelinate concrete have been investigated. Many experiments were carried out by replacing cement with different percentages of
met

... Show More
View Publication Preview PDF
Crossref (8)
Crossref
Publication Date
Wed Jan 01 2014
Journal Name
Lap Lambert Academic Publishing
High Order Tow Point Boundary Value Problems And Its Applications
...Show More Authors

The aim of this book is to present a method for solving high order ordinary differential equations with two point boundary condition of the different kind, we propose semi-analytic technique using two-point osculatory interpolation to construct polynomial solution. The original problem is concerned using two-points osculatory interpolation with the fit equal numbers of derivatives at the end points of an interval [0 , 1] . Also, we discussion the existence and uniqueness of solutions and many examples are presented to demonstrate the applicability, accuracy and efficiency of the methods by compared with conventional method .i.e. VIDM , Septic B-Spline , , NIM , HPM, Haar wavelets on one hand and to confirm the order convergence on the other

... Show More
View Publication
Publication Date
Sun Jul 31 2022
Journal Name
International Review Of Civil Engineering (irece)
Bearing Capacity Factor of Shallow Foundation on Reinforced Sloped Clayey Soil
...Show More Authors

The placement of buildings and structures on/or adjacent to slopes is possible, but this poses a danger to the structure due to failures that occur in slopes. Therefore, a solution or improvement should be determined for these issues of the collapse of the structure as a result of the failure of the slopes. A laboratory model has been built to test the impact of some variables on the bearing capacity factor. The variables include the magnitude of static axial load applied at the center of footing, the depth of embedment, the spacing between geogrid reinforcement layer and the numbering of the geogrid sheet under the footing, the inclination angle of slope clayey soil (β), the spacing between the footing's edge and the slope's end (b/H). Th

... Show More
View Publication
Crossref
Publication Date
Fri Mar 01 2019
Journal Name
Iraqi Journal Of Physics
Wear rate of epoxy resin reinforced with multi walls carbon nanotubes
...Show More Authors

In this study, nanocomposites have been prepared by adding
multiwall carbon nanotubes (MWCNTs) with weight ratios (0, 2, 3,
4, 5) wt% to epoxy resin. The samples were prepared by hand lay-up
method. Influence of an applied load before and after immersion in
sodium hydroxide (NaOH) of normality (0.3N) for (15 days) at
laboratory temperature on wear rate of Ep/MWCNTs
nanocomposites was studied. The results showed that wear rate
increases with increasing the applied load for the as prepared and
immersed samples and after immersion. It was also found that epoxy
resin reinforced with MWCNTs has wear rate less than neat epoxy.
The sample (Ep + 5wt% of MWCNTs) has lower wear rate. The
immersion effect in base so

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Nov 01 2022
Journal Name
Journal Of Engineering
Study The Impact of Geopolymer Mortar Reinforced by Micro Steel Fibers
...Show More Authors

In this research, geopolymer mortar had to be designed with 50% to 50% slag and fly ash with and without 1% micro steel fiber at curing temperature of 240℃. The molarity of alkaline solution adjusted with 12 molar sodium hydroxid to sodium silicate was 2 to 1, reaspectivly. The heat of curing increased the geopolymerization proceses of geoplymer mortar, which led to increasing strength, giving the best result and early curing age. The heat was applied for two days by four hours each day. It was discovered in the impact test that the value first crack of each mix was somewhat similar, but the failure increased 72%  for the mixture that did not contain fiber. For the energy observation results it was shown that the mixt

... Show More
View Publication Preview PDF
Crossref (3)
Crossref