A Mesoscopic Simulation for the Early-Age Shrinkage Cracking Process of High Performance Concrete in Bridge Engineering

Abstract

On a mesoscopic level, high performance concrete (HPC) was assumed to be a heterogeneous composite material consisting of aggregates, mortar, and pores. The concrete mesoscopic structure model had been established based on CT image reconstruction. By combining this model with continuum mechanics, damage mechanics, and fracture mechanics, a relatively complete system for concrete mesoscopic mechanics analysis was established to simulate the process of early-age shrinkage cracking in HPC. This process was based on the dispersion crack model. The results indicated that the interface between the aggregate and mortar was the crack point caused by shrinkage cracks in HPC. The locations of early-age shrinkage cracks in HPC were associated with the spacing and the size of the aggregate particle. However, the shrinkage deformation size of the mortar was related to the scope of concrete cracking and was independent of the crack position. Whereas lower water to cement ratios can improve the early strength of concrete, this ratio cannot control early-age shrinkage cracks in HPC.

Early Cracking Risk Prediction Model of Concrete under the Action of Multifield Coupling

“…(5) Equation ( 5) was substituted into equation (2), and the risk prediction model of early cracking of modern concrete was obtained as follows:…”

“…However, there are some problems of modern concrete, such as the rapid hydration, the large shrinkage, the rapid internal temperature rises, and the rapid internal humidity decrease, which led to early cracking of concrete. If the early cracks of concrete cannot be strictly controlled, especially the cracks caused by nonload factors in the early stage of concrete structure, the durability and safety of concrete would be reduced [1][2][3][4][5]. Meanwhile, fiber [6] would be used to improve the anticracking property of concrete.…”

“…e above research showed that the early anticracking property of concrete had a complex relationship with cement hydration, temperature, humidity, shrinkage, and creep. Many scholars have studied the early anticracking property of concrete with mineral admixtures such as fly ash and slag but have not yet reached a consistent conclusion [2,[13][14][15]. erefore, it is necessary to propose an accurate method to predict the early cracking risk of modern concrete.…”

Meso-Scale Simulation of Concrete Uniaxial Behavior Based on Numerical Modeling of CT Images

“…With the increasing application of concrete, it becomes more important to study its mechanical properties by numerical simulation. The performances of mesoscale concrete were investigated by the early-age shrinkage cracking process of high-performance concrete [2], impact performances of reinforced concrete beams [3], spatial variability of chloride and its influence on the thickness of concrete cover [4], the effective thermal conductivity of tensile cracked concrete [5,6], and the behavior of concrete under high confinement [7], respectively.…”

Mesoscopic Finite Element Modeling of Concrete Considering Geometric Boundaries of Actual Aggregates

“…e aggregate sizes were normalized, and the double criterion was used to judge the aggregate intrusion. Li and Wang [28] established a relatively complete system for concrete mesoscopic mechanics analysis to simulate the process of early-age shrinkage cracking in high-performance concrete based on CT image reconstruction. Although the CT reconstruction technology can characterize the shape of the actual aggregate satisfactorily, the aggregate shape and gradation are limited by the specific slice.…”