Table 2. Field trials: observations... | Emerald Publishing

Table 2.

Field trials: observations based on monitoring through 2012–2013

Field sites	Observations
Alabama	Treatment of ASR-affected arches was ‘not’ effective There has been no reduction in relative humidity, and expansion continues unabated
Arkansas	Too early to draw conclusions
Delaware	No ASR-performance data available DOT overlaid lithium-treated pavement with asphalt before the impact of the lithium could be evaluated Testing of cores indicated very little lithium penetration and it is highly unlikely that the treatment would have impacted the course of ASR
Maine	Too early to draw conclusions for abutments and wing walls, but it is possible that moisture supply from behind the treated elements masks any benefit of silane applied to the surface The application of a silane to a slender circular column may have reduced expansion, but longer-term data needed to confirm trend
Massachusetts	Silanes appear to have been effective in reducing expansion and reducing the visual symptoms of ASR (‘drying’ of cracks) Lithium treatments (topical or vacuum impregnation) have had no beneficial impact Elastomeric coating performing well Longer-term data required to confirm long-term performance
Rhode Island	Too early to draw conclusions
Texas (Houston)	The extent of ASR appears to vary significantly between columns tested, making it difficult to determine the impact of the treatment There is evidence that silanes have reduced the internal relative humidity to some extent and have reduced expansion in the long term Electrochemical lithium treatment appears to have increased expansion. This may be due to a combination of the significant resaturation that occurs during treatment and the concentration of alkali hydroxides around the steel (cathode)
Texas (New Braunfels)	Based on petrographic evaluation and other microstructural studies, ASR was found not to be a significant mechanism of distress. The primary mechanism for observed distress has not been proven, but it is potentially due to excessive volume changes owing to shrinkage (chemical, autogenous, drying)
Vermont	Too early to draw conclusions Treatments have improved the visible appearance of the barriers. This is not surprising for the coating product, but the silanes have reduced the staining associated with the cracks, giving the appearance of reducing the damage

Field sites	Observations
Alabama	Treatment of ASR-affected arches was ‘not’ effective There has been no reduction in relative humidity, and expansion continues unabated
Arkansas	Too early to draw conclusions
Delaware	No ASR-performance data available DOT overlaid lithium-treated pavement with asphalt before the impact of the lithium could be evaluated Testing of cores indicated very little lithium penetration and it is highly unlikely that the treatment would have impacted the course of ASR
Maine	Too early to draw conclusions for abutments and wing walls, but it is possible that moisture supply from behind the treated elements masks any benefit of silane applied to the surface The application of a silane to a slender circular column may have reduced expansion, but longer-term data needed to confirm trend
Massachusetts	Silanes appear to have been effective in reducing expansion and reducing the visual symptoms of ASR (‘drying’ of cracks) Lithium treatments (topical or vacuum impregnation) have had no beneficial impact Elastomeric coating performing well Longer-term data required to confirm long-term performance
Rhode Island	Too early to draw conclusions
Texas (Houston)	The extent of ASR appears to vary significantly between columns tested, making it difficult to determine the impact of the treatment There is evidence that silanes have reduced the internal relative humidity to some extent and have reduced expansion in the long term Electrochemical lithium treatment appears to have increased expansion. This may be due to a combination of the significant resaturation that occurs during treatment and the concentration of alkali hydroxides around the steel (cathode)
Texas (New Braunfels)	Based on petrographic evaluation and other microstructural studies, ASR was found not to be a significant mechanism of distress. The primary mechanism for observed distress has not been proven, but it is potentially due to excessive volume changes owing to shrinkage (chemical, autogenous, drying)
Vermont	Too early to draw conclusions Treatments have improved the visible appearance of the barriers. This is not surprising for the coating product, but the silanes have reduced the staining associated with the cracks, giving the appearance of reducing the damage