Dear reader we have already learnt about regions in United States where different weathering regions are specified in ASTM C33. A region can be said to be under negligible weathering, where concrete hardly exposed to detrimental effect of freezing under presence of moisture.
Here we will include limits of deleterious substances and also expected physical properties of aggregate to be used in such weathering regions. Dear reader we have already discussed about deleterious substances that are found in aggregates. Aggregates are classified as 1N and 2N. ‘N’ stands for negligible weather condition, we can easily gaze this.
ASTM do not specified limits of chart having specific gravity less than 2.4 and no information about soundness (tested under magnesium sulfate for 5 cycles). We have discussed many posts about soundness of aggregate; you can read this for more information. We are providing a table to specify the limits and properties:
1N- in this class designation the concrete location or types includes:
- Concrete slabs that are subjected to abrasion due to traffic
- Bridge floor
- Bridge deck and side walk
2N-includes all other concrete; types or location other than for 1N.
Dear reader we will discuss about the application and limitation of this table in next part to be published soon.