Influence of reactivity and dosage of MgO expansive agent on shrinkage and crack resistance of face slab concrete

Wang, Lei; Li, Guoxin; Li, Xiang; Guo, Fanxing; Tang, Shengwen; Lu, X.; Hanif, Asad

doi:10.1016/j.cemconcomp.2021.104333

Cited by 108 publications

(46 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These results indicate that M300 seems to act as an inert material at the early stage of cement hydration. This trend has also been reported by other studies [36,85]. Mo et al [85] reported that the hydration degree of M300 with water is only 4.5% at 2 days and 9.9% at 7 days.…”

Section: Hydration Heat Results Of Lhp Cement Paste Added With Mgosupporting

confidence: 87%

“…The concrete specimens were used to study the effects of MgO on mechanical property, drying, and autogenous shrinkage, pore structures, and fractal characteristics of LHP concrete. In practical applications, a MgO dosage range of 4-8% is usually suggested [36]. Thus, the MgO replacement for cement ratios of 0, 4 wt.%, and 8 wt.% were adopted to prepare the concrete.…”

Section: Proportion Designmentioning

confidence: 99%

“…Thus, it was more applicable for compensating the early quick shrinkage of thin concrete structures resulting from the rapid loss of water from their highly exposed surfaces or from a rapid temperature drop at initial hydration time when the concrete tensile strength is not high [25,33,34]. On the contrary, Type II MgO, which begins to produce expansion only at a later age, is more beneficial for massive concrete structures, since it can compensate the thermal stressinduced shrinkage that persists for one or more years after concrete casting [28,33,35,36].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Influence of MgO on the Hydration and Shrinkage Behavior of Low Heat Portland Cement-Based Materials via Pore Structural and Fractal Analysis

Wang

Liu

et al. 2022

Fractal Fract

Self Cite

View full text Add to dashboard Cite

Currently, low heat Portland (LHP) cement is widely used in mass concrete structures. The magnesia expansion agent (MgO) can be adopted to reduce the shrinkage of conventional Portland cement-based materials, but very few studies can be found that investigate the influence of MgO on the properties of LHP cement-based materials. In this study, the influences of two types of MgO on the hydration, as well as the shrinkage behavior of LHP cement-based materials, were studied via pore structural and fractal analysis. The results indicate: (1) The addition of reactive MgO (with a reactivity of 50 s and shortened as M50 thereafter) not only extends the induction stage of LHP cement by about 1–2 h, but also slightly increases the hydration heat. In contrast, the addition of weak reactive MgO (with a reactivity of 300 s and shortened as M300 thereafter) could not prolong the induction stage of LHP cement. (2) The addition of 4 wt.%–8 wt.% MgO (by weight of binder) lowers the mechanical property of LHP concrete. Higher dosages of MgO and stronger reactivity lead to a larger reduction in mechanical properties at all of the hydration times studied. M300 favors the strength improvement of LHP concrete at later ages. (3) M50 effectively compensates the shrinkage of LHP concrete at a much earlier time than M300, whereas M300 compensates the long-term shrinkage more effectively than M50. Thus, M300 with an optimal dosage of 8 wt.% is suggested to be applied in mass LHP concrete structures. (4) The addition of M50 obviously refines the pore structures of LHP concrete at 7 days, whereas M300 starts to refine the pore structure at around 60 days. At 360 days, the concretes containing M300 exhibits much finer pore structures than those containing M50. (5) Fractal dimension is closely correlated with the pore structure of LHP concrete. Both pore structure and fractal dimension exhibit weak (or no) correlations with shrinkage of LHP concrete.

show abstract

Section: Hydration Heat Results Of Lhp Cement Paste Added With Mgosupporting

confidence: 87%

Section: Proportion Designmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Influence of MgO on the Hydration and Shrinkage Behavior of Low Heat Portland Cement-Based Materials via Pore Structural and Fractal Analysis

Wang

Liu

et al. 2022

Fractal Fract

Self Cite

View full text Add to dashboard Cite

show abstract

“…Concrete is a traditional construction material that is applied widely for defense and civil applications such as protective structures, infrastructures, bridges and buildings [8][9][10]. These structures can experience impact loads periodically in the form of gunshots or blast loading.…”

Section: Projectile Impact On Concretementioning

confidence: 99%

Effect of Needle Type, Number of Layers on FPAFC Composite against Low-Velocity Projectile Impact

et al. 2021

View full text Add to dashboard Cite

Protective structures subjected to intensive loads that may benefit from the use of multilayer composite structures with excellent hardness and impact resistance represent an emerging research field in recent times. In this study, low-velocity projectile impact tests were performed on Functionally-graded Preplaced Aggregate Fibrous Concrete (FPAFC) mixtures to evaluate their performance. The effects of projectile needle type, fibre type and hybridization in addition to the number of layers in the composites on projectile impact were investigated. The bioinspiration of the excellent impact strength of turtle shells was used to design an FPAFC comprising a higher amount of steel and polypropylene fibres at the outer layers. In parallel, one and two-layered concretes were also cast to assess the effectiveness of three-layered FPAFC. The tests were performed on disc specimens using non-deformable compound bevel, convex edge and hollow edge projectiles. The damage severity was quantified by the top damage area, bottom damage area and depth of penetration. In addition, a simple analytical model for predicting the composite mass expulsion was developed and implemented. Findings indicated that regardless of fiber type and distribution, the compound bevel projectile needle produced the lowest impact numbers for all single, double and triple-layer specimens compared to the convex edge and hollow edge projectiles. Repeated projectile impacts increased the penetration depth and damaged area at the top and bottom surfaces of all targets. Targets were more resistant to convex edge and hollow edge projectile penetration than the compound bevel. The experimental and analytical model results for mass expelled from the top surface are reasonably acceptable. This research gives an idea of developing advanced fibrous composite with superior impact resistance for the promising protective structures.

show abstract

“…For instance, to increase the toughness of concrete, many kinds of fibers are widely used to develop sustainable hydraulic concrete with high ductility [21,22]; in recent years, to reduce the thermal shrinkage and reduce the cracking risk, low heat Portland cement has been used to lower the cement hydration heat [14,23,24]; to improve the mechanical properties and microstructure of concrete, nanomaterials such as silica fume are adopted [14,25]; to compensate the drying shrinkage and autogenous shrinkage, MgO expansion agent is used, etc. [26,27]. Overall, many innovations in sustainable hydraulic concrete have enabled the design and construction of sustainable and durable infrastructure.…”

Section: Introductionmentioning

confidence: 99%

Sustainable High-Performance Hydraulic Concrete

et al. 2022

Self Cite

View full text Add to dashboard Cite

show abstract

Influence of reactivity and dosage of MgO expansive agent on shrinkage and crack resistance of face slab concrete

Cited by 108 publications

References 41 publications

Influence of MgO on the Hydration and Shrinkage Behavior of Low Heat Portland Cement-Based Materials via Pore Structural and Fractal Analysis

Influence of MgO on the Hydration and Shrinkage Behavior of Low Heat Portland Cement-Based Materials via Pore Structural and Fractal Analysis

Effect of Needle Type, Number of Layers on FPAFC Composite against Low-Velocity Projectile Impact

Sustainable High-Performance Hydraulic Concrete

Contact Info

Product

Resources

About