Long-Term Concrete Shrinkage Influence on the Performance of Reinforced Concrete Structures

Abstract

The contribution of concrete to the tensile stiffness (tension stiffening) of a reinforced concrete (RC) member is a key governing factor for structural serviceability analyses. However, among the current tension stiffening models, few consider the effect brought forth by concrete shrinkage, and none studies take account of the effect for very long-term shrinkage. The present work intends to tackle this exact issue by testing multiple RC tensile elements (with different bar diameters and reinforcement ratios) after a five-year shrinking time period. The experimental deformative and tension stiffening responses were subjected to a mathematical process of shrinkage removal aimed at assessing its effect on the former. The results showed shrinkage distinctly lowered the cracking load of the RC members and caused an apparent tension stiffening reduction. Furthermore, both of these effects were exacerbated in the members with higher reinforcement ratios. The experimental and shrinkage-free behaviors of the RC elements were finally compared to the values predicted by the CEB-fib Model Code 2010 and the Euro Code 2. Interestingly, as a consequence of the long-term shrinkage, the codes expressed a smaller relative error when compared to the shrinkage-free curves versus the experimental ones.

A Review of Recent Distributed Optical Fiber Sensors Applications for Civil Engineering Structural Health Monitoring

“…A proper shrinkage strain measurement is imperative for a proper assessment of the tension stiffening as it may lead to an apparent underestimation [82]. To remove such effect, the authors used some guidelines provided in Fields and Bischoff [83] and found a good agreement with the DOFS experimental results for the rebar 15 M specimens and not so good agreement with the rebar 10 M specimens.…”

Synthesis and Performances of Shrinkage-Reducing Polycarboxylate Superplasticizer in Cement-Based Materials

“…When concrete is used in building structures, it will be restricted by many factors, such as steel or adjacent structures. Under both the influence of the shrinkage process and external constraints, the concrete matrix usually develops harmful cracking [ 1 , 2 , 3 ]. Due to shrinkage cracking, a pathway is created for the penetration of aggressive agents (i.e., chlorides, sulfate) into the cement-based materials, thereby deteriorating the long-term durability and serviceability of the concrete structure [ 4 , 5 , 6 ].…”

“…Drying shrinkage and autogenous shrinkage are the main shrinkage types of cement-based materials. The basic mechanism of shrinkage is that the volume of the microstructure in the cement matrix decreases due to water loss [ 2 , 3 ]. These two kinds of shrinkage occur continuously in the service process of cement-based materials and have a great impact on engineering applications.…”

Influence of Concrete Strength Class on the Long-Term Static and Dynamic Elastic Moduli of Concrete

“…Material properties have a direct effect on the behavior of structural elements in buildings. It was reported that long-term concrete shrinkage results in a decreased magnitude of the load, causing the occurrence of the first crack in reinforced concrete elements and reducing the tension stiffening mechanism for lower longitudinal reinforcement ratios [8].…”