• Tiada Hasil Ditemukan

STEEL FIBRES AS FLEXURAL CRACKS INHIBITOR IN REINFORCED FIBROUS

N/A
N/A
Protected

Academic year: 2022

Share "STEEL FIBRES AS FLEXURAL CRACKS INHIBITOR IN REINFORCED FIBROUS "

Copied!
5
0
0

Tekspenuh

(1)

UNIVERSITI TEKNOLOGI MARA

STEEL FIBRES AS FLEXURAL CRACKS INHIBITOR IN REINFORCED FIBROUS

CONCRETE BEAMS UNDER STATIC LOADING

MOHD YUASRIZAM BIN MUSA

Thesis submitted in fulfilment o f the requirements for the degree of

Master of Science

Faculty of Civil Engineering

June 2015

(2)

AUTHOR’S DECLARATION

I declare that the work in this thesis was carried out in accordance with the regulations o f Universiti Teknologi MARA. It is original and is the results o f my own work, unless otherwise indicated or acknowledged as referenced work. This thesis has not been submitted to any other academic institution or non-academic institution for any degree or qualification.

I, hereby, acknowledge that I have been supplied with the Academic Rules and Regulations for Post Graduate, Universiti Teknologi MARA, regulating the conduct o f my study and research.

Name o f Student Student I.D. No Programme Faculty Thesis Title

Mohd Yuasrizam bin Musa 2011177963

Master o f Civil Engineering Civil Engineering

Steel Fibres as Flexural Cracks Inhibitor in Reinforced Fibrous Concrete Beam under Static Loading

Signature o f Student

Date June 2015

(3)

ABSTRACT

Flexural cracks are the most common problem in structural members which are subjected to bending moments. The introduction o f steel fibres in concrete beam has been proposed as flexural cracks inhibitor. This research o f steel fibres as flexural cracks inhibitor in concrete beam under static loading was conducted focusing on simply supported beam to determine the crack propagations in flexure by varying the steel fibre content placement in the beam. The 25 kg/m 3 steel fibre was chosen for this study since the optimum concrete strength (fcu) is achieved with this steel fibre dosage.

Seven sets o f concrete beams o f 150 mm x 250 mm x 1000 mm in size consists o f three RC beams with full steel fibrous concrete (SFRC), three RC beams with steel fibre placed within tension zone o f the beam, three RC beams with steel fibre placed at the half o f tension zone o f the beam, two conventional RC beams (without steel fibre) as control sample, one unreinforced concrete beam with full steel fibre, one unreinforced concrete beam with steel fibre at tension zone only and one unreinforced concrete beam with steel fibre at half o f tension zone. The variations in these seven sets o f beams is intended to find the optimum steel fibrous concrete placements towards inhibiting flexural cracks in the beam. Experiment was conducted through three points bending test. The results showed that addition o f steel fibre in conventional reinforced concrete beam increase the crack initiation load, yield load and ultimate load by 60%, 69% and 56% respectively. It also reduced the ratio o f ultimate load over yield load by 46% and increased the ratio o f ultimate load over theoretical load by 40%. The crack opening is reduced by 11 %. The crack failure o f all the beams are classified as flexure crack and occurred in the mid third span. The addition o f steel fibre in the conventional RC beam showed that it inhibits the flexural cracks.

(4)

ACKNOW LEDGEMENT

With the name o f Allah, with the greatest love, the most gracious, and the most merciful, with His permission this research was completed as what had been plan. A few persons i would like to express my gratitude for helping me in completing this research works.

In particular, I wish to extend my gratitude and appreciation to my supervisors, Prof. Ir.

Dr. Siti Hawa Hamzah, who guided and advised me from the very beginning up to the completion o f this research works. Their willingness to help expand my knowledge and expertise is deeply appreciated. Grateful acknowledgement also due to Dr. Norliyati Mohd Amin, my associate supervisor, for providing valuable time, support and suggestions.

I would like to give my special appreciation to the Heavy Structure Crews and all technical officer o f the Civil Engineering Faculty for their invaluable assistance and cooperation in conducting the experimental work. Special thanks to the administrative staff o f the Institution o f Postgraduate Studies and the Faculty o f Civil Engineering, their help for administrative part always greatly appreciated.

To my beloved parents, with your greatest love and prayer, I am able to get this successfulness.

(5)

CHAPTER ONE INTRODUCTION

1.1 BACKGROUND

The most important material in concrete structure is concrete and it is playing a part in all building structures. It is broadly used in the building construction because o f its advantages such as the moulded ability to take up various structural forms or shapes required with minimal cost. Reinforced concrete beam is a composite material consisting reinforcement bars embedded in a hardened concrete matrix. It is also a composite material o f dry mix that consists o f cement, coarse aggregates and fine aggregates (Bhatt et. al, 2006). Concrete which carries the compressive forces is assisted by the reinforcement bar which resists tensile forces.

The reinforced concrete beams are arguably the most used in the buildings construction. However, concrete is known as a brittle material and weak in tension.

Cracking will take place whenever tension occurs in concrete beam and it becomes a fundamental weakness o f concrete. Cracking that occurred when stresses in the concrete exceed the concrete strength is usually a major problem for concrete structure usually in terms o f site application, resistance to loading and general lack o f durability.

Cracking is one o f the common problems in the concrete structure. Structural members which are subjected to bending moment such as slabs and beams will develop flexural cracks. Flexural cracks occur when the stresses in the tension zone exceed the bending strength o f the concrete. Primary cracks is form first and secondary cracks will forms when moment is increase. In the practical purposes, it can be assumed that the cracks will extend the crack line from the tension face to the location o f zero stress o f the beam cross section. Tensile strength o f concrete is only about 10% o f the compressive strength o f concrete and the reinforcement bars is designed to resist these tensile forces which are transferred by bond between the interfaces o f concrete and reinforcement bars (Mosley et. al, 1999).

Cracks are induced in reinforced concrete elements as a results o f flexural tensile stress due to bending under applied loads, diagonal tension stress due to shear applied loads, volume changes due to shrinkage, creep, thermal and chemical effects and

1

Rujukan

DOKUMEN BERKAITAN

1) To determine the optimum percentage of the specific type of SFs used in this study for C30 and C50 classes of concrete based on the cube compressive strength and flexural

The main goal of this research is to evaluate the behaviour of U and L-shaped end anchored steel plate on flexurally strengthened reinforced concrete (r.c.) beams in view of

A total of three reinforced concrete beams were casted and tested to study the effect of replacing steel reinforcement with GFRP sections on the flexural behaviour of the beam..

This research emphases on flexural capacity assessment and investigation of failure modes of Carbon Fiber Reinforced Polymers (CFRP) strengthened brick aggregated RC beams..

It was found that strengthening the opening at the flexure zone of beams significantly increased beam strength and reduced deflection and cracks compared to

but not in flood depth with the value o f MAE are slightly increase went resampling been made and for SRTM show loss o f model accuracy due to resampling with the F- statistic o

This study was looking at the potential o f utilizing concrete filled square thin walled steel section with a newly proposed stiffening system as structural

A report submitted to Universiti Teknologi MARA in partial fulfilment o f the requirements for the Degree o f Bachelor o f Engineering (Hons.) (Civil).. in the Faculty o f