Cracking Factors and Crack Control of Steel-concrete Composite Beam Panels
YU Yingxia
GUO Jie
WANG Yanming
LI Wenjie
Abstract：Steel-concrete composite beams have a large span,and the panels near the negative bending moment area are prone to cracking.Identifying the factors that influence cracking and determining effective crack control measures are of great significance for the development of long-span steel-concrete bridges.Based on the concrete cracking mechanism and the refined model of the 80 m span steel-concrete beam,the crack development of various influencing factors under different construction loads was analyzed.Combined with the in-situ test,the construction method with better crack control effect was determined and applied.The results indicate that the impact of concrete strength and steel reinforcement stress on crack propagation decreases linearly,and a steel fiber content ranging from 0.5%～1.5%can enhance the crack resistance of concrete.An appropriate increase in the reinforcement ratio can inhibit crack development,but when it exceeds 2.0%,the effect becomes less significant.Under negative temperature differences,when the vehicle is overloaded by 60%,the crack width increases by 49%.After the lifting and pulling superposition technology and the optimized construction sequence were adopted,the compressive stress reserve of the panel increased by 6.32 MPa,and the tensile region converged.The monitoring values of the secondary side span demonstrate that the bridge deck is better able to resist crack development under this control measure.
Keywords：long-span steel-concrete beamnegative moment regioncrack openingin-situ testcrack controlCzochralski superposition
Publication Date：2025-02-24
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：10( 58-67 )