Principal Component and Multiple Regression Analysis for Steel Fiber Reinforced Concrete (SFRC) Beams

Mohammad S Islam,Shahria Alam

doi:10.1007/s40069-013-0059-7

Abstract

This study evaluates the shear strength of steel fiber reinforced concrete (SFRC) beams from a database, which consists of extensive experimental results of 222 SFRC beams having no stirrups. In order to predict the analytical shear strength of the SFRC beams more precisely, the selected beams were sorted into six different groups based on their ultimate concrete strength (low strength with f c ′ < 50 MPa and high strength with f c ′ < 50 MPa ), span-depth ratio (shallow beam with a/d ≥ 2.5 and deep beam with a/d < 2.5) and steel fiber shape (plain, crimped and hooked). Principal component and multiple regression analyses were performed to determine the most feasible model in predicting the shear strength of SFRC beams. A variety of statistical analyses were conducted, and compared with those of the existing equations in estimating the shear strength of SFRC beams. The results showed that the recommended empirical equations were best suited to assess the shear strength of SFRC beams more accurately as compared to those obtained by the previously developed models.

Highlights

The concept of fiber reinforcing in concrete was introduced more than a century ago, and since various types of fibers have been utilized in concrete
No particular trend was observed between the strength of steel fiber reinforced concrete (SFRC) beams and the aspect ratio of steel fibers used in concrete
4.1 Proposed Shear Strength Predict Model 4.1.1 Multiple Regression Analysis In order to predict the analytical shear strength of SFRC beams more accurately, the experimental shear strength of the selected six types of SFRC beams was analyzed with the five parameters of ultimate compressive strength, tensile reinforcement ratio (q), span-depth ratio (a/d), shape factor of steel fiber and the volume of steel fibers

Summary

Introduction

The concept of fiber reinforcing in concrete was introduced more than a century ago, and since various types of fibers have been utilized in concrete. The inclusion of steel fibers to an ordinary reinforced concrete beam suppresses shear failure in favour of more ductile behaviour (Mansur et al 1986; Narayanan and Darwish 1987; Ramakrishna and Sundararajan 2005). The increase in shear strength contributed by the steel fibers widely varied from 13 to 170 % (Narayanan and Darwish 1988), 58–125 % (Greenough and Nehdi 2008) and 22–89 % (Swamy et al 1993) due to the variations of fiber volume, its aspect ratio and anchorage condition, tensile reinforcement ratio, and compressive strength of concrete beams, respectively

Objectives

Results

Conclusion