“…Bulk resistivity measurements when curing is done in a moist room are somewhat complex to interpret and ideally these measurements should be done on specimens immersed in limewater or simulated pore solutions, which ensures controlled leaching and degree of saturation [ 32 ]. These last two curing choices were deliberately not utilized here because of the potential for reactions between calcium hydroxide that is deposited on the surface and deicing salt solutions that complicate interpretations of damage [ 33 ]. Fig.…”
Section: Resultsmentioning
confidence: 99%
“…There was a strong linear relationship between the two parameters. Theoretically, because the bulk resistivity is affected by a number of experimental variables, it is often stated that the formation factor is a better parameter to use for durability assessments [ 33 ]. In this study, while there is some scatter, formation factor and bulk resistivity were interchangeable.…”
Section: Resultsmentioning
confidence: 99%
“…The results show that increasing SCM replacement and air content significantly reduce the damage at any given exposure duration, an observation in alignment with literature [ 15 ]. The increase in durability due to air entrainment could be linked to the reduction in the degree of saturation due to changed (slower) sorption behavior of the air voids [ 3 , 33 , 35 ]. In addition, the air voids provide ‘space’ which reduces expansion/crystallization pressures associated with the formation of calcium oxychloride and other phases [ 3 ].…”
Section: Resultsmentioning
confidence: 99%
“…In previous work [ 15 ], distinct non-linearity/bi-linear mass change behavior was apparent in mixtures with high SCM and high air content. Sorption in cementitious materials when plotted against the square root of time is known to follow bi-linear behavior with initial and final sorption behaviors being controlled by matrix saturation and air void saturation, respectively [ 3 , 33 , 38 ]. The linear behavior and the low values of mass change could imply that the air voids in high SCM/high air mixtures are unsaturated, due to a more refined microstructure and less aggressive exposure conditions [ 15 , 34 ].…”
Section: Resultsmentioning
confidence: 99%
“…The linear behavior and the low values of mass change could imply that the air voids in high SCM/high air mixtures are unsaturated, due to a more refined microstructure and less aggressive exposure conditions [ 15 , 34 ]. However, sorption in cementitious materials, even with water, is complex, and affected strongly by specimen preparation and other factors [ 33 , 34 , 38 , 39 ]. For high concentrations of salt solutions, due to the chemical interactions affecting transport [ 40 ], advanced reactive transport models are likely needed to fundamentally explain mass change behavior.…”
In cold regions, calcium and magnesium chloride deicing salts damage concrete pavements due to the formation of certain deleterious chemical phases, including calcium oxychloride. While there is much research at a cement paste-scale, damage in concrete has been less studied. In this study, we evaluate concrete damage due to calcium and magnesium chloride and explain the roles of supplementary cementitious materials (SCM) replacement level, air entrainment, salt type, and exposure conditions in damage development. Various non-destructive test methods including bulk resistivity, mass change, and visual damage assessment were used to monitor the damage over time. Damage was reduced as the SCM replacement level and air content increased, regardless of exposure conditions. Bulk resistivity and visual assessment were promising indicators of damage. The product of 91-day bulk resistivity and the air content predicted concrete performance when exposed to concentrated deicing salts. Based on several criteria, mixtures with 20% fly ash replacement level or 35% slag mitigated damage significantly when the air content was greater than 5% by concrete volume. Damage mitigation mechanisms of SCM and air are discussed.
Supplementary Information
The online version contains supplementary material available at 10.1617/s11527-022-01992-y.
“…Bulk resistivity measurements when curing is done in a moist room are somewhat complex to interpret and ideally these measurements should be done on specimens immersed in limewater or simulated pore solutions, which ensures controlled leaching and degree of saturation [ 32 ]. These last two curing choices were deliberately not utilized here because of the potential for reactions between calcium hydroxide that is deposited on the surface and deicing salt solutions that complicate interpretations of damage [ 33 ]. Fig.…”
Section: Resultsmentioning
confidence: 99%
“…There was a strong linear relationship between the two parameters. Theoretically, because the bulk resistivity is affected by a number of experimental variables, it is often stated that the formation factor is a better parameter to use for durability assessments [ 33 ]. In this study, while there is some scatter, formation factor and bulk resistivity were interchangeable.…”
Section: Resultsmentioning
confidence: 99%
“…The results show that increasing SCM replacement and air content significantly reduce the damage at any given exposure duration, an observation in alignment with literature [ 15 ]. The increase in durability due to air entrainment could be linked to the reduction in the degree of saturation due to changed (slower) sorption behavior of the air voids [ 3 , 33 , 35 ]. In addition, the air voids provide ‘space’ which reduces expansion/crystallization pressures associated with the formation of calcium oxychloride and other phases [ 3 ].…”
Section: Resultsmentioning
confidence: 99%
“…In previous work [ 15 ], distinct non-linearity/bi-linear mass change behavior was apparent in mixtures with high SCM and high air content. Sorption in cementitious materials when plotted against the square root of time is known to follow bi-linear behavior with initial and final sorption behaviors being controlled by matrix saturation and air void saturation, respectively [ 3 , 33 , 38 ]. The linear behavior and the low values of mass change could imply that the air voids in high SCM/high air mixtures are unsaturated, due to a more refined microstructure and less aggressive exposure conditions [ 15 , 34 ].…”
Section: Resultsmentioning
confidence: 99%
“…The linear behavior and the low values of mass change could imply that the air voids in high SCM/high air mixtures are unsaturated, due to a more refined microstructure and less aggressive exposure conditions [ 15 , 34 ]. However, sorption in cementitious materials, even with water, is complex, and affected strongly by specimen preparation and other factors [ 33 , 34 , 38 , 39 ]. For high concentrations of salt solutions, due to the chemical interactions affecting transport [ 40 ], advanced reactive transport models are likely needed to fundamentally explain mass change behavior.…”
In cold regions, calcium and magnesium chloride deicing salts damage concrete pavements due to the formation of certain deleterious chemical phases, including calcium oxychloride. While there is much research at a cement paste-scale, damage in concrete has been less studied. In this study, we evaluate concrete damage due to calcium and magnesium chloride and explain the roles of supplementary cementitious materials (SCM) replacement level, air entrainment, salt type, and exposure conditions in damage development. Various non-destructive test methods including bulk resistivity, mass change, and visual damage assessment were used to monitor the damage over time. Damage was reduced as the SCM replacement level and air content increased, regardless of exposure conditions. Bulk resistivity and visual assessment were promising indicators of damage. The product of 91-day bulk resistivity and the air content predicted concrete performance when exposed to concentrated deicing salts. Based on several criteria, mixtures with 20% fly ash replacement level or 35% slag mitigated damage significantly when the air content was greater than 5% by concrete volume. Damage mitigation mechanisms of SCM and air are discussed.
Supplementary Information
The online version contains supplementary material available at 10.1617/s11527-022-01992-y.
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