Shear strength and behavior of ultra-high performance fiber reinforced concrete (UHPC)‎ deep beams without web reinforcement

Other Title(s)

مقاومة القص و سلوك العتبات الخرسانية المسلحة العميقة ذات الأداء الفائق دون استخدام التسليح الوتري

Dissertant

Ali, Mushir Hasan

Thesis advisor

Aziz, Umar Qarani

Comitee Members

Ahmad, Salah al-Din A.
Yusuf, Ali Ramadan
Said, Sarkawt A.

University

Salahaddin University-Hawler

Faculty

College of Engineering

Department

Architectural Department

University Country

Iraq

Degree

Master

Degree Date

2012

English Abstract

Ultra-high performance fiber reinforced concrete (UHPC) is a new class of concrete that has been developed in recent decades, it has enhanced properties such as; very high compressive strength, improved tensile strength, durability and due to presence of steel fibers the concrete shows more ductility than conventional types of concrete.

In this study, three types of concrete were used based on the compressive strength of concrete, named; Normal Strength Concrete (NSC) of (f c=42 MPa).

High Strength Concrete (HSC) of (f c=63.75 MPa) and Ultra High Performance Concrete (UHPC) of (f c=134.5 MPa).

The experimental program included casting and testing of fifteen reinforced concrete deep beams without web reinforcement (stirrups), nine specimens of (UHPC), three specimens of (HSC) and three specimens of (NSC), in order to study the shear strength and behavior of deep beams under two point loading.

Considered variables were; the compressive strength of concrete (42, 63.75 and 134.5 MPa), the shear span to depth ratio (a / d) (1, 1.5 and 2) and over all depth of the beam (h) (180, 240 and 300 mm), while the width of all beams was (120 mm).

The experimental results showed that the failure load is increased by about 44 % and 150 % when the compressive strength of concrete increased from 42 MPa to 63.75 MPa and from 63.75 MPa to 134.5 MPa respectively, also they indicated that the shear span to depth ratio (a / d) has a significant effect on failure load, it can be seen that by increasing (a / d) ratio from 1 to 1.5 then to 2, lead to decreasing the failure load by 30% and 150 % respectively, while the increase in overall depth of the beam from (180 to 240) mm reduces the nominal shear stress significantly, but beyond which no obvious size effect can be seen.

After generation of flexural cracks, at the same applied load level, the central deflection of beams decreased by 155 % and 110 % by increasing the compressive strength of concrete from 42 MPa to 134.5 MPa and from 63.75 MPa to 134.5 MPa respectively.

The average ratio of diagonal cracking load and failure load obtained in analysis of deep beams by ANSYS program to those observed experimentally, was about (1.1) for Ultra High Performance Concrete (UHPC) deep beams, this means that the analysis by ANSYS is overestimate by about 10 %.

Main Subjects

Civil Engineering

Topics

• Mechanical properties
• Reinforced concrete

No. of Pages

106

Table of Contents

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-314515