SAMPLING AND TESTING HIGHWAY MATERIALS. 71 



cubic yards excavated, or when the quality or appearance of the gravel changes, and 

 at such other times as may be directed by the engineer. 



(3^ Where andhoio taken. — (a) Sampling at the pit: Enough samples shall be taken 

 to represent an average of the material. An individual sample must be taken through 

 a full vertical section of that material which it is proposed to use at the point selected. 

 Each sample shall be taken from a freshly exposed vertical face. 



(b) Sampling from cars, barges, etc.: Enough samples shall be taken, as directed 

 by the engineer, to represent average composition. Samples from cars shall be taken 

 from both ends and from top and bottom of the car. 



(4) Amount and size of sample. — (a) Sampling for quality: For screened gravel 

 sample shall weigh 25 to 30 pounds. For bank gravel sample shall weigh 50 to 75 

 pounds. 



(b) Sampling for size: A sample for size shall weigh not less than 10 pounds for mate- 

 rials of three-quarter-inch maximum diameter or less. Samples of materials of other 

 sizes shall increase in weight to a maximum of approximately 60 pounds, varying with 

 the size and weight of the largest pieces represented by the sample. The sample shall 

 be representative of the product as delivered for use. 



(5) Marking and shipping. —Samples shall be shipped in tight boxes or bags and shall 

 be accompanied by a card in the container or securely attached thereto, stating date, 

 by whom taken, by whom submitted, source of supply, exact location where sample 

 was taken, proposed purpose to which the material is to be put, space for remarks, and, 

 in case of pit or bank investigation, owner, quantity available, amount and character 

 of stripping, whether material from same source has been previously used, where and 

 for what purpose and with what residts, haul to nearest point on road, average haul to 

 job, character of haul, initial cost of gravel. 



Notification of sampling, containing the above data, shall be forwarded separately 

 to the laboratory immediately upon taking the sample. 



56. SAMPLING SAND. 



(1) By ivhom taken. — Samples are to be taken by the engineer or his authorized 

 representative. 



(2) When taken. — Samples are to be taken from the proposed source of supply at 



least days before the sand is to be accepted or rejected, also from every cubic 



yards excavated, or when the quality or appearance of the sand changes, and at such 

 other times as may be directed by the engineer. 



(3) Where and how taken. — Samples shall be taken from freshly exposed portions of 

 the deposit as directed by the engineer. Mixed samples may be taken if deemed 

 necessary. 



In general, the number of samples shall be sufficient to cover the extreme variation 

 of quality in that part of the deposit which is proposed to be used. 



(4) Amount and size of sample. — Each sample, whether individual or composite, 

 shall weigh between 10 and 15 pounds. 



(5) Marking and shipping. — Samples shall be shipped in tight boxes or bags and shall 

 be accompanied by a card in the container or securely attached thereto, stating date, 

 by whom taken, by whom submitted, source of supply, exact location where sample 

 was taken, proposed purpose to which the material is to be put, space for remarks, and 

 in case of source investigation, owner, quantity available, amount and character of 

 stripping, whether material from same source has been previously used, where and 

 for what purpose, and with what results, haul to nearest point on road, average haul 

 to job, character of haul, initial cost of sand. 



Notification of sampling, containing the above data, shall be forwarded separately 

 to the laboratory immediately upon taking the sample. 



