research centers


Search results: Found 3

Listing 1 - 3 of 3
Sort by

Article
Fresh and Hardened Properties ofLightweight Self CompactingConcrete Containing Attapulgite

Authors: Waleed A. Abbas --- Qais J.Frayyeh --- Shubbar J. Al Obaidey
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2016 Volume: 34 Issue: 9 Part (A) Engineering Pages: 1767-1781
Publisher: University of Technology الجامعة التكنولوجية

Loading...
Loading...
Abstract

The main objectives of this study were investigating the possibility of producing lightweight self -Compacting concrete (LWSCC) by using artificial coarse lightweight aggregate manufactured by burning locally available Attapulgite clay, estimating the optimum dosage of high reactivity Attapulgite (HRA) and studying its effects on fresh and hardened properties of LWSCC when using it as a partial replacement by weight of cement.Tests results showed that, It is possible to produce (LWSCC) by using Attapulgite as artificial coarse (LWA) and (HRA).The optimum content for (HRA) used in this study was 10 %, the percentages of increment in compressive strength and splitting tensile strength with 10% (HRA) relative to reference mix were (10.0%, 12.1%, 11.1% and 12.4%) and ( 12.0%, 18.2%, 16.6% and 16.2%) for 7, 28, 56 and 90 days respectively.The values of the calculated equilibrium density ranged between (1788 and 1829) kg/m3


Article
The Effect of Using Multi Types of Mineral Admixtures on Some Properties of Lightweight Self-Compacting Concrete

Authors: Waleed A. Razaq --- Qais J.Freih --- Shubbar J. Al Obaidey
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2019 Volume: 37 Issue: 1 Part (c) special Pages: 186-194
Publisher: University of Technology الجامعة التكنولوجية

Loading...
Loading...
Abstract

Abstract The main objective of this research was studying the effects of usingmulti types of mineral admixtures as high reactivity Attapulgite (HRA), highreactivity Metakaolin (HRM) and fly ash (FA) on some rheological andmechanical properties of lightweight self - Compacting concrete (LWSCC), whenwere used as a partially replacement by weight of cement. The results showed thatusing of (HRA) and (HRM) increased the superplasticizer (SP) dosage, while (FA)with spherical particles reduced the (SP) dosage relative to reference mix (Ref.mix) to get the same slump flow target value. The optimum content for (HRA) usedin this study was 10 %, and the percentages of increment in compressive strengthand splitting tensile strength relative to (Ref.mix) were (10.0%, 12.2%, 11.15%and 12.3%) and ( 8.8%, 17.46%, 16.34% and 14.66%) for 7, 28, 56 and 90 daysrespectively. Using of (FA) reduced early age strength, but long term strengthincreased with (FA) content increases. LWSCC mix contained 10% (HRM)showed a better mechanical properties than both (HRA) and (FA) LWSCC mixes,and the percentages of increment when cement was replaced with 10 % (HRM)relative to (Ref.mix) were (15.0%, 17.6%, 13.9% and 15.7%) and (16.0%, 24.2%,22.2% and 21.6%) at 7, 28, 56, and 90 days for compressive strength and splittingtensile strength respectively


Article
The Effects of Maximum Attapulgite Aggregate Size and Steel Fibers Content on Fresh and Some Mechanical Properties of Lightweight Self Compacting Concrete
تأثير المقاس الاقصى لركام الاتبلغايت ومحتوى الالياف الفولاذية على الخواص الطرية وبعض الخواص الميكانيكية للخرسانة خفيفة الوزن ذاتية الرص

Author: Shubbar Jawad K. Al- Obaidey شبر جواد كاظم العبيدي
Journal: Journal of Engineering مجلة الهندسة ISSN: 17264073 25203339 Year: 2020 Volume: 26 Issue: 5 Pages: 172-190
Publisher: Baghdad University جامعة بغداد

Loading...
Loading...
Abstract

The main objectives of this study were investigating the effects of the maximum size of coarse Attapulgite aggregate and micro steel fiber content on fresh and some mechanical properties of steel fibers reinforced lightweight self-compacting concrete (SFLWSCC). Two series of mixes were used depending on maximum aggregate size (12.5 and 19) mm, for each series three different steel fibers content were used (0.5 %, 1%, and 1.5%). To evaluate the fresh properties, tests of slump flow, T500 mm, V funnel time, and J ring were carried out. Tests of compressive strength, splitting tensile strength, flexural tensile strength, and calculated equilibrium density were done to evaluate mechanical properties. For reference mixes, the results showed that mixes with a larger maximum aggregate size of 19 mm exhibited better fresh properties, while mechanical properties negatively affected by using a larger maximum aggregate size. The results also showed that using steel fibers led to negative effects on fresh properties, especially with higher steel fibers content and larger maximum aggregate size. The marginal effect of steel fibers on compressive strength was noticed, while for both splitting and flexural tensile strength, significant increase was obtained with increasing of steel fibers content. The properties of SFLWSCC in the fresh state had a considerable effect on mechanical properties, whereas with the best fresh properties, the best mechanical properties can be obtained.

أن الاهداف الرئيسية لهذه الدراسة كانت التحري عن تأثير المقاس الاقصى لركام الاتبلكايت الخشن ومحتوى الالياف الفولاذية المايكروية على الخواص الطرية وبعض الخواص الميكانيكية للخرسانة خفيفة الوزن ذاتية الرص المسلحة بالالياف. لتحقيق اهداف هذه الدراسة تم استخدام سلسلتان من الخلطات اعتمادا على المقاس الاقصى للركام (12.5 و19) ملم, لكل سلسلة من الخلطات تم استخدام ثلاث محتويات مختلفة من الالياف الفولاذية (0.5%, 1%و 1.5%). لتقييم الخواص الطرية تم اجراء فحوصات جريان الهطول, زمن T500ملم, Jring و Lbox. فحصوصات مقاومة الانضغاط, مقاومة شد الانشطار, مقاومة شد الانثناء و الكثافة المتوازنة المحسوبة تم اجرائها لتقييم الخواص الميكانيكية. أظهرت النتائج للخلطات المرجعية ان الخلطات الحاوية على ركام ذو مقاس اقصى اكبر(19 ملم) أبدت خواص طرية أفضل, بينما الخواص الميكانيكية تأثرت سلبا بزيادة المقاس الاقصى للركام. أظهرت النتائج ايضا بأن استخدام الالياف الفولاذية أدى الى تأثيرات سلبية على الخواص الطرية وخصوصا مع محتوى الياف اعلى ومقاس ركام اقصى أكبر. لوحظ تأثير هامشي للألياف الفولاذية على مقاومة ألانضغاط بينما تم الحصول على زيادات مهمة لكل من مقاومة شد الانشطار ومقاومة شد الانثناء مع زيادة محتوى الالياف. ان الخواص الطرية للخرسانة خفيفة الوزن ذاتية الرص المسلحة بالالياف لها تأثير مهم على الخواص الميكانيكية, حيث ان مع الخواص الطرية الافضل يمكن الحصول على الخواص الميكانيكية الافضل.

Listing 1 - 3 of 3
Sort by
Narrow your search

Resource type

article (3)


Language

English (3)


Year
From To Submit

2020 (1)

2019 (1)

2016 (1)