New Jersey

Department of Transportation

Standard Specifications

for Road and Bridge Construction

2007

NJDOT C-3 – Calcium Nitrite Presence in Plastic Concrete

1. Scope. This test method is used to determine the presence of calcium nitrite in the plastic concrete state. Perform testing on a freshly mixed concrete sample.
   
   
2. Apparatus. Use the following apparatus and materials:
   
   
   1. Quantofix Test Strips for high range nitrite No. 91322.
   2. 10 cubic centimeter disposable syringes with Leur-Lok tip No. 309604.
   3. Disposable filters 1 inch/0.45 micron No. SLHA02510.
   4. Wide-mouth container.
   5. Measuring cups marked in milliliters.
   
   
3. Procedure. Perform the following steps:
   
   
   1. Determine the amount of concrete to be tested based on the design amount of Calcium Nitrite and Table C-3-1. Add concrete to pre-measured 0.5 gallons of water in a wide mouth container. Use the water in the container to rinse out the measuring cup.
   2. Shake the container for 2 to 5 minutes until contents are well mixed.
   3. Using the syringe, uptake approximately 10 milliliters of extraction water from the container. Attach a disposable filter to the end of the syringe.
   4. Filter the extraction water into a clean cup.
   5. Dip the test strip into the clear, filtered extraction water and compare the color to the chart on the side of the test strip container.
   6. Use the Table C-3-1 to determine if the reading on test strips corresponds with the expected reading for the design amount of Calcium Nitrite.



Table C-3-1 – Parameters for Calcium Nitrite Testing
Design Amount of Calcium Nitrite, gal/CY	Volume of Concrete to be Added, oz.	Expected Reading on Test Strip
2.0	8	0.3
2.5	6	0.3
3.0	5	0.3
3.5	4	0.3
4.0	8	0.6
4.5	7	0.6
5.0	6	0.6



4. Report. Report the reading on the test strip. Report if the sample passed or failed.