Calcium oxychloride formation in pastes containing supplementary cementitious materials: Thoughts on the role of cement and supplementary cementitious materials reactivity

Suraneni, Prannoy; Azad, Vahid Jafari; Isgor, Burkan; Weiss, Jason

doi:10.21809/rilemtechlett.2016.7

Cited by 57 publications

(15 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…binder composition (more than just the physical strength of the paste). Suraneni et al [40] studied the formation of calcium oxychloride in concrete. It is an expansive reaction that involves both calcium chloride, CaCl 2 , and calcium hydroxide, Ca(OH) 2 , as reactants.…”

Section: B Chemical Reaction With Deicing Saltmentioning

confidence: 99%

“…As CaCl 2 is often used as de-icing chemical and as the calcium oxychloride formation is favored at low temperatures, the chemical attack aggravates the salt frost scaling. Suraneni et al [40] demonstrated that the use of fly ash limits calcium oxychloride formation, because the pozzolanic reaction consumes the calcium hydroxide formed during cement hydration, and then calcium hydroxide becomes in short supply for the calcium oxychloride formation. However, the degree of cement substitution needs to be high to effectively bring down the content of calcium hydroxide.…”

Section: B Chemical Reaction With Deicing Saltmentioning

confidence: 99%

See 1 more Smart Citation

Frost resistance of concrete with high contents of fly ash - A study on how hollow fly ash particles distort the air void analysis

Hasholt

Christensen

Pade

2019

Cement and Concrete Research

View full text Add to dashboard Cite

Cenospheres are hollow fly ash particles. When performing air void analysis on a contrast enhanced plane section, air inclusions in cenospheres are counted as air voids. In the present study, air void analyses for air entrained concrete mixtures with fly ash (up to 50% of binder mass) were corrected based on chord counting for non-air entrained paste samples with various contents of fly ash. The correction only lead to a small reduction of the total air content, but it increased the spacing factor up to 25%. The concrete mixtures were also exposed to salt frost scaling testing. The amounts of scaling were unacceptable for several mixtures with high dosages of fly ash. Inferior strength or inadequate air void structure could not explain this. Additional testing pointed to that chemical surface degradation aggravated the physical frost attack for concrete mixtures with high contents of fly ash.

show abstract

Section: B Chemical Reaction With Deicing Saltmentioning

confidence: 99%

Section: B Chemical Reaction With Deicing Saltmentioning

confidence: 99%

Frost resistance of concrete with high contents of fly ash - A study on how hollow fly ash particles distort the air void analysis

Hasholt

Christensen

Pade

2019

Cement and Concrete Research

View full text Add to dashboard Cite

show abstract

“…Although not reported here due to space constraints, research has also been performed on other SCMs at different w:cm values (15,19). Thermogravimetric analysis was performed on ground, hydrated powder to determine the CH content.…”

Section: Experimental Methodsmentioning

confidence: 99%

“…Several strategies have been proposed to mitigate CAOXY formation (14)(15)(16)(17)(18)(19). First, the use of supplementary cementitious materials (SCMs) such as fly ash, slag, and silica fume lead to a reduction in CAOXY contents due to a reduction in CH contents (14,18,19). Second, topical sealers can be used to create a physical barrier between CH and salt solution to prevent their reaction (14).…”

Section: Reducing Joint Damage Caused By Salt-matrix Reactionsmentioning

confidence: 99%

Use of Fly Ash to Minimize Deicing Salt Damage in Concrete Pavements

Suraneni

Azad

Isgor

et al. 2017

Transportation Research Record: Journal of the Transportation R

Self Cite

View full text Add to dashboard Cite

Premature damage has been observed at the joints in numerous concrete pavements where calcium chloride and magnesium chloride deicing salts have been used. This damage results from a reaction between the deicing salt and the calcium hydroxide (CH) in the hydrated cement paste. This reaction leads to the formation of an expansive product known as calcium oxychloride (CAOXY). The use of supplementary cementitious materials as a replacement for cement has been proposed to reduce the CH that is available in the mixture to react with the deicing salts. Reducing the CH can reduce the amount of CAOXY that forms. In this study, mixtures representative of paving concrete were made with cements and fly ashes from across the country. CH amounts were determined by using thermogravimetric analysis, and CAOXY amounts were determined by using low-temperature differential scanning calorimetry. Various replacement levels of fly ash were used to demonstrate that the main parameter that influences the amounts of CH and CAOXY that form is the replacement level of fly ash. This paper proposes that a prescriptive specification requiring 35% cement replacement by volume with fly ash would reduce the damage caused by CAOXY formation and further proposes a performance specification to limit the CAOXY formation to below 15 g/100 g paste.

show abstract

“…The former mechanism can be resolved through utilizing air-entrained admixtures which can establish an adequate void system to resist ice expansion pressures [10,11]. The latter can be addressed through using proper supplementary cementitious materials (SCMs) as a partial replacement of ordinary portland cement (OPC) to improve the durability of concrete in the presence of deicing salts through dilution and/or pozzolanic reactions [15][16][17][18][19][20][21].…”

Section: Introductionmentioning

confidence: 99%

Reducing Damage Due to Chemical Reactions in Concrete Exposed to Sodium Chloride: Quantification of a Deleterious Chemical Phase Change Formation

Althoey

Farnam

2019

MATEC Web Conf.

View full text Add to dashboard Cite

It has been shown that sodium chloride can react with the tricalcium aluminate (C3A) and its hydrates, leading to a formation of a deleterious chemical phase change during thermal cycling. It is believed that this chemical phase change is implicated in the premature deterioration of concrete pavements in the cold regions. This work examines the potential formation of the deleterious chemical phase change in several cementitious pastes made using different types of portland cement and supplementary cementitious materials (SCMs). The amount of the chemical phase change was quantified using a low-temperature differential scanning calorimetry. The results indicated that the formation of the chemical phase change can be reduced by using cements with low C3A content. The addition of SCMs showed different effects on the chemical phase change formation. Slag and Class F fly ash could reduce the amount of the chemical phase change due to only the dilution effect whereas silica fume could significantly reduce the amount of the chemical phase change due to the dilution effect as well as pozzolanic reactions. Adversely, the addition of Class C fly ash showed a negative effect through increasing the formation of the chemical phase change.

show abstract

Calcium oxychloride formation in pastes containing supplementary cementitious materials: Thoughts on the role of cement and supplementary cementitious materials reactivity

Cited by 57 publications

References 37 publications

Frost resistance of concrete with high contents of fly ash - A study on how hollow fly ash particles distort the air void analysis

Frost resistance of concrete with high contents of fly ash - A study on how hollow fly ash particles distort the air void analysis

Use of Fly Ash to Minimize Deicing Salt Damage in Concrete Pavements

Reducing Damage Due to Chemical Reactions in Concrete Exposed to Sodium Chloride: Quantification of a Deleterious Chemical Phase Change Formation

Contact Info

Product

Resources

About