defg
Structural
- Jul 7, 2006
- 55
Dear Sir,
I have come across some various road projects, where the medium curing grade is applied with respect to weather condition (climatically condition)e.g atmospheric temperature during construction.Light grades say MC-30 are usually used in cool weather MC-70 is normally preferred in hot and dry regions. In our specification require the Contractor to use MC-70 for priming works as the project road is found in dry and hot climatic condition. The Contractor is asking for a permission to use MC-30 instead of MC-70.Iwent through the testing manual (AASHTO M82-75(1993) and found that most of the properties requrement, min.and max. are same except the following tests:
Kinematic viscosity at 60Centigrade(MC-30, 30min and 60max)CSt for MC-70 is(70min and 140max)CSt
Distilate,percentage by volume of total distillate to 360Centigrade
Residue from distillation to 360Centigrade.
Is it possible to allow the Contractor to use MC-30 instead of MC-70 as specified? OR there will be detrimental deffect! Please assist
I have come across some various road projects, where the medium curing grade is applied with respect to weather condition (climatically condition)e.g atmospheric temperature during construction.Light grades say MC-30 are usually used in cool weather MC-70 is normally preferred in hot and dry regions. In our specification require the Contractor to use MC-70 for priming works as the project road is found in dry and hot climatic condition. The Contractor is asking for a permission to use MC-30 instead of MC-70.Iwent through the testing manual (AASHTO M82-75(1993) and found that most of the properties requrement, min.and max. are same except the following tests:
Kinematic viscosity at 60Centigrade(MC-30, 30min and 60max)CSt for MC-70 is(70min and 140max)CSt
Distilate,percentage by volume of total distillate to 360Centigrade
Residue from distillation to 360Centigrade.
Is it possible to allow the Contractor to use MC-30 instead of MC-70 as specified? OR there will be detrimental deffect! Please assist
