Title:
Shear in Concrete Beams Reinforced with High- Performance Steel
Author(s):
Admasu S. Desalegne and Adam S. Lubell
Publication:
Structural Journal
Volume:
112
Issue:
6
Appears on pages(s):
783-792
Keywords:
beams; high-performance reinforcement; Modified Compression Field Theory; reinforced concrete; safety; strains
DOI:
10.14359/51687798
Date:
11/1/2015
Abstract:
There is increasing interest in the use of high-performance reinforcing steel in concrete structures as a means to reduce the life-cycle costs of civil infrastructure. ASTM A1035 Grade 690 (100 ksi) steel offers improved corrosion resistance compared to traditional reinforcing steels. Efficient use of its higher strength can enable decreased reinforcement congestion. However, to efficiently exploit the available strength, sectional shear design models must adequately account for the higher expected strains in both longitudinal and transverse reinforcement. This paper presents the test results of eight shear-critical beams used to validate and enhance existing shear capacity models. Specimens were longitudinally reinforced with ASTM A1035 Grade 690 (100 ksi) steel and transversely reinforced with either ASTM A1035 Grade 690 (100 ksi) or ASTM A615 Grade 400 (60 ksi) steel. Overall specimen heights of 1000 mm (39.4 in.) and a constant shear span-depth ratio of 3.0 were used. The main test variables were the longitudinal reinforcement ratio and the steel type for the transverse reinforcement. The load-deflection response, ultimate load-carrying capacity, and mode of failure were of primary interest. The shear capacity of the new test specimens and other published data were compared against analytical shear design models. Good agreement in the shear capacity predictions was achieved from a modified form of the CSA A23.3 capacity model, which directly accounts for the reinforcement strains at the critical section.