Multi-scale analytical theory of the diffusivity of concrete subjected to mechanical stress

Jin, Liu; Zhang, Renbo; Du, Xiuli; Li, Yue

doi:10.1016/j.conbuildmat.2015.07.123

Cited by 42 publications

(27 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The microstructure of the ITZ in concrete varies widely from what is found in cement paste (greater porosity, precipitation of long portlandite crystals and greater ettringite content) [11]. It is regarded as the third constituent phase in concrete, along with coarse aggregate and cement paste [12]. A full understanding of this region would afford a scientific explanation for the macroscopic performance of recycled concrete given: a) the effect of the zone on concrete strength and permeability; and b) the possible of impact of a larger number of recycled aggregate/paste ITZs present in new eco-efficient concretes [12].…”

Section: Accepted Manuscriptmentioning

confidence: 99%

Properties of interfacial transition zones (ITZs) in concrete containing recycled mixed aggregate

Bosque

Zhu

Howind

et al. 2017

Cement and Concrete Composites

228

View full text Add to dashboard Cite

Concretes containing mixed recycled aggregate (RA) have a larger number of coarse aggregate/paste interfacial transition zones (ITZs) than conventional concretes, due to the various component materials present in recycled aggregate. This study investigated the properties of various RA/paste ITZs in concrete using nanoindentation and scanning electron microscopy (SEM) and analysed the possible impact of the properties of the ITZs on the macromechanical performance of recycled concrete. It was found that the elastic modulus of the ITZ varies with the type of constituent materials present in recycled aggregate, with ITZs associated with organic components (e.g. wood, plastic and asphalt) exhibiting lower minimum elastic modulus values. The impact of ITZ properties on macro-mechanical properties of concrete depends on the relative content of different constituent materials present in the recycled aggregate and the micro-mechanical properties of the ITZs involved.

show abstract

Section: Accepted Manuscriptmentioning

confidence: 99%

Properties of interfacial transition zones (ITZs) in concrete containing recycled mixed aggregate

Bosque

Zhu

Howind

et al. 2017

Cement and Concrete Composites

228

View full text Add to dashboard Cite

show abstract

“…The above phenomenon has been researched by Wang et al (2017), Li et al (2018) and Wang et al (2018). At higher compressive stress (σ c > 0.3f c ), new micro-cracks would form and the concrete would exhibit inelastic deforma- tions (Jin, Zhang, Du, & Li, 2015;Xu & Li, 2017;Wang et al, 2019). Nevertheless, if the increase in volume due to formation of new micro-cracks is less than the decrease in volume of concrete pores, there would be overall reduction of CO 2 diffusion channels (Wang et al, 2018), and the carbonation depth would decrease.…”

Section: Establishing Equations For Stress Influence Coefficientmentioning

confidence: 99%

Effect of Concrete Stress States on Carbonation Depth of Concrete

Wang

et al. 2019

Journal of Civil Engineering and Management

View full text Add to dashboard Cite

Carbonation can lead to reduction of alkalinity of concrete and initiation of steel reinforcement corrosion. In durability design of concrete structures, the carbonation depth should be duly considered. However, the concrete stress state would influence the carbonation depth, and there has been inadequate research on such effect. In this study, it is proposed to introduce a stress influence coefficient to the concrete carbonation depth model. With reference to the experimental data from eleven research studies in the literature encompassing both tensile and compressive stress states, the relationship between stress influence coefficient and concrete stress ratio is quantitatively investigated, and mathematical equations relating the stress influence coefficient with the concrete stress ratio are established. Comparative study with three typical existing groups of equations shows that the proposed equations of stress influence coefficient are more reasonable and have a higher reliability. The effects of carbonation time, mix proportions of concrete on stress influence coefficient are also analysed, and the magnitudes of the effects are found to be approximately within ±10%. Finally, the modified carbonation depth models are proposed and verified by the experimental data, which suggests that the proposed models are of desirable accuracy. Adoption of the proposed equations as the modified formula of stress influence coefficient in the concrete carbonation depth model for practical applications is recommended.

show abstract

“…Recently, based on elastic theories, Li (2016, 2017), Du et al (2015) and Jin et al (2015) established elastic models to investigate the chloride diffusivity of water-saturated concrete or cement paste under compressive/tensile loads in low stress levels. To obtain explicit mathematical expressions, those models required specific geometric (micro/meso) structures of CBPMs.…”

Section: Introductionmentioning

confidence: 99%

“…To obtain explicit mathematical expressions, those models required specific geometric (micro/meso) structures of CBPMs. For instance, Xu and Li (2016) and Du et al (2015) employed a simply spherical core-shell structure (or two-phase ring structure for two-dimensional case) to represent the pore-solid system of cement paste, and Xu and Li (2017) and Jin et al (2015) extended this simple geometry to a multilayer structure for concrete modelling. The microstructure of CBPMs, however, would be much more complex than the simple core-shell structure (Zeng et al 2010(Zeng et al , 2012a(Zeng et al , 2012b(Zeng et al , 2013(Zeng et al , 2014a(Zeng et al , 2016.…”

Section: Introductionmentioning

confidence: 99%

“…Here, following the studies by Li (2016, 2017), Du et al (2015) and Jin et al (2015), and taking the same scope of elasticity, a porosity-stress function based on micromechanical principles and volumeaveraging scheme for a water-saturated pore-solid system is established first. The responses of chloride diffusivity to porosity change are evaluated by an empirical model proposed by Zheng and Zhou (2008).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Poroelastic Insights into Stress Dependence of Chloride Penetration into Saturated Cement-Based Porous Materials

Zeng

Wang

2019

ACT

View full text Add to dashboard Cite

Most concrete structures service under external loads and the studies of the external-loading effects on chloride diffusivity in these porous media remain insufficient. This paper reports a relationship between porosity variation and external load inspired by poroelastic theory. This porosity-load relationship, together with an empirical equation for chloride diffusivity versus porosity, provides an explicit diffusivity-load model for saturated porous media. Without the specific assumptions of geometries of the pores and the matrix phases, the present model shows flexible expressions. Comprehensive analyses are performed to demonstrate the effects of external load and initial porosity on the porosity variation, chloride diffusion coefficient, penetration depth and durable time of specific cement-based samples. Two models reported in the literature are employed for the purpose of comparison. Overall, initial porosity is a primarily dominative factor affecting the chloride diffusivity, penetration profile and durability of cement-based porous materials. Within the elastic regime, external loads only influence the outcomes in limited degrees.

show abstract

Multi-scale analytical theory of the diffusivity of concrete subjected to mechanical stress

Cited by 42 publications

References 35 publications

Properties of interfacial transition zones (ITZs) in concrete containing recycled mixed aggregate

Properties of interfacial transition zones (ITZs) in concrete containing recycled mixed aggregate

Effect of Concrete Stress States on Carbonation Depth of Concrete

Poroelastic Insights into Stress Dependence of Chloride Penetration into Saturated Cement-Based Porous Materials

Contact Info

Product

Resources

About