Measuring the Effect of Strengthened Concrete on the Fracture Characteristics of Notched Concrete Beams Through a Three-Point Beam Test

This study explores the effect of increased concrete strength on the behavior of concrete failure. Experimental testing using a three-point bend (TPB) test proposed by RILEM was carried out to calculate the value of fracture energy (GF), stress intensity factor (KIC), and characteristic length (lch) of the concrete. The values of GF and lch, which are proportional to the fracture process zone based on the fictitious crack model, were employed to determine the effect of concrete strength on the concrete’s fracture characteristic. KIC was engaged to describe the initial crack in the concrete. Four different concrete strengths of 40, 47, 53, and 100 MPa—were manufactured to produce notched beam specimens with single-sized notches 25 mm deep. Results revealed that the values of GF and KIC increased in the stronger concretes. However, the value of lch decreased significantly as concrete strength increased

Experimental investigation of the flexural ductility of singly reinforced concrete beam using normal and high strength concrete

This paper discusses and reports based on the experimental investigation of the flexural ductility of singly reinforced normal strength and high strength concrete beams. Compressive concrete strength of 40 and 95 MPa were employed to create singly reinforced normal strength and high strength concrete beams, respectively. Fourteen samples made of normal and high strength concrete were engaged to observe the flexural ductility behaviour of beams on the basis of four point bend testing. Analysis on the basis of the flexural cracking, ultimate failure and curvature ductility were carried out to derive the comparison of singly reinforced normal strength and high strength beams. The beams using high strength concrete revealed a higher ductility ratio than that of normal strength concrete, i.e. 4.50 for high strength concrete and 2.60 for normal strength concrete