Engineering and Technology Journal

One Parameter Composite Semigroups of Linear Bounded Operators in Strong Operator Topology of Schatten Class Cp

Samir Kasim Hassan; Al-Taie M; Al-Malki Anam; Al-Attar Abeer; Mustafa Khaleel Ismael; Fatema Ahmed Sadeq; Radhi A .Zboon; Jehad R.Kider; Samir K .Hassan; Hussain J. M. Alalkawi; Raad H. Majid; Rawaa A. Alomairy; Luma Abdul Ghani Zghair; Hadia Kadhim J.Al-Ogili; Assifa M. Mohamad; Abbas Sheyaa Alwan; Haider L. Aneed; Assim H Yousif; Salema Sultan Salman; Abbas Hussien Miry; Abduladhem A.Ali; Mohammed Zeki Al-Faiz; Sabah N. mahmood; Khansaa Dawood Selman; Shaymaa Tareq Kadhim

Volume 29, Issue 8 , June 2011, , Page 1463-1470

https://doi.org/10.30684/ etj.29.8.2

Abstract

For semigroups of linear bounded operators on Hilbert spaces, the problem of being in Cp , 0 Keywords Read More ...

Behavior of Plain and High Performance Polypropylene Fiber Concrete Subjected to Elevated Temperatures

Luma Abdul Ghani Zghair

Volume 29, Issue 8 , June 2011, , Page 1517-1535

https://doi.org/10.30684/ etj.29.8.8

Abstract

The aim of this work is to determine the residual compressive strength and splitting tensile strength after exposure to an elevated temperature (between100 to 500 C ◌ْ ) of plain ... Read More ... The aim of this work is to determine the residual compressive strength and splitting tensile strength after exposure to an elevated temperature (between100 to 500 C ◌ْ ) of plain and polypropylene fiber reinforced concrete (PPFRC) in comparison with specimens exposed to ordinary temperature 25C ◌ْ . High – performance concrete mixes were produced by using high rang reducing agent superplasticizer (SP) and 10% high reactivity metakaoline (HRM) as a partial replacement by weight of cement (350)Kg/m3 . A single concrete mix with HRM, SP and four PPF contents of (0.25, o.5, o.75 and 1%) by volume were adopted. The workability of the concrete was kept constant ( slump 100 ± 5mm ).Each group of specimens ( plain and PPFRC ) was heated to a specified temperature and kept at the temperature for one hour before being gradually cooled to room temperature and then they were tested . The results show at ordinary temperatures 25 C ◌ْ, the addition of fiber volume fraction (VF%) of (0.25%) increases the compressive ( 20.6% ) comparable to HPC without fiber . While the addition of ( 0.5 , 0.75 and 1% ) of polymer fibers , the compressive strength decreased (12.6 , 19 and 33%) respectively comparable to HPC without fiber . On the other hand the addition of (VF%) of (0.25) increased splitting tensile strength ( 15%) comparable to HPC without fiber . while the addition of fiber volume fraction (VF%) of (0.5 ) increased splitting tensile strength by a percentage which is lower than that in specimens with VF% of 0.25 , the increase in splitting tensile strength was ( 6%) comparable to HPC without fiber at ordinary temperatures The results also shows that , when (1% ) fibers was used , the splitting tensile strength decreased ( 10.8%) in comparable to HPC without fiber At elevated temperature the results show an appreciable decrease in compressive strength and splitting tensile strength after exposure to temperature higher than 300 C ◌ْ of both plain and PPFRC Specimens containing PPF ( 0.25 , 0.5 , and 0.75 %) the percentage of reduction in splitting tensile strength is lower than that in HPC specimens ( without fibers ) after exposure to a temperature ( 500 ,300 and 100 C ◌ْ ) comparable to normal temperature 25C ◌ْ .While specimen containing PPF ( 1% ) the percentage of reduction in splitting tensile strength was higher than specimen without PPF after exposure to a similar temperature .On the other hand , specimens containing PPF ( 0.25 , 0.5 , 0.75 and 1 %) the percentage of reduction in compressive strength is higher than that in HPC specimens ( without fibers ) after exposure to a temperature (500 ,300 and 100 C ◌ْ). comparable to normal temperature 25C ◌ْ

Mechanical Properties of High Performance Carbon Fiber Concrete

Wasan I. Khalil; Akar Abdulrazaq

Volume 29, Issue 5 , March 2011, , Page 906-924

https://doi.org/10.30684/ etj.29.5.7

Abstract

In this research mechanical properties of high performance carbon fiber concrete are studied. The experimental work includes, producing high performance concrete using superplasticizer ... Read More ...

Predicting Mechanical Properties of High Performance Concrete by Using Non-destructive Tests

Shakir A. Al-Mishhadani; Waleed A. Al-Qaisi; Sura F. Al-Khafaji

Volume 27, Issue 3 , February 2009, , Page 425-444

https://doi.org/10.30684/etj.27.3.3

Abstract

In this study, high performance concrete mixes were produced by using highrange water reducing agent and also by using 10% silica fume or 10% highreactivity metakaolin as a partial ... Read More ...

Keywords = high performance concrete

One Parameter Composite Semigroups of Linear Bounded Operators in Strong Operator Topology of Schatten Class Cp

Abstract

Behavior of Plain and High Performance Polypropylene Fiber Concrete Subjected to Elevated Temperatures

Abstract

Mechanical Properties of High Performance Carbon Fiber Concrete

Abstract

Predicting Mechanical Properties of High Performance Concrete by Using Non-destructive Tests

Abstract