High-strength steel bar and method for controlling minimum reinforcement ratio of concrete plate flexural member through high-strength steel bars

Abstract

The invention discloses a high-strength steel bar. The high-strength steel bar comprises 0.18-0.28% of C, 0.45-0.85% of Si, 1.35-1.65% of Mn, 0.09-0.26% of combined elements of V+Ti+Nb, 0.01-0.06% of Cr, 0.01-0.06% of Ni, 0-0.05% of Cu, 0-0.01% of Mo, 0.025% of P or less, 0.025% of S or less, 0.005-0.015% of N and the balance Fe and unavoidable impurities. The yield strength and tensile strength are improved, the plasticity is not lowered, and the yield strength can reach 600 MPa or more, so that when the high-strength steel bar is applied to a concrete plate flexural member, the minimum reinforcement ratio of the concrete plate flexural member is set as the larger value between 0.15 and 45ft / fy.

Description

technical field

[0001] The invention relates to a steel bar and a production process thereof, in particular to a high-strength steel bar and a method for controlling the minimum reinforcement percentage of a concrete slab type bending member. Background technique

[0002] High-strength steel bars refer to steel for reinforced concrete and prestressed reinforced concrete, whose cross-section is circular, sometimes square with rounded corners. Including plain round bars, ribbed bars, twisted bars. In the prior art, steel bars are classified into grade I reinforcement (grade 235 / 370) according to mechanical properties; grade II reinforcement (grade 335 / 510); grade III reinforcement (370 / 570) and grade IV reinforcement (540 / 835). The latter two types of steel bars are high-strength steel bars.

[0003] Common types of high-strength steel bars are as follows:

[0004] (1) Micro-alloyed hot-rolled ribbed steel bar: hot-rolled ribbed steel bar with improved yield strength and ul...