Caltrans is accepting industry comments as it reviews and updates CT125, the sprawling testing procedure that covers the collection of samples for highway materials used in roadway structural sections, including asphalt.

The current version of CT125 was published in May of 2014. Previous updates have been published on the Caltrans website in 2000, 2002 and 2010. The current version can be downloaded HERE.

The 19-page document sets out the exact procedures to be followed for "obtaining representative samples of various highway materials and products that are incorporated in roadway structural sections."

"Representative sampling is defined as the taking of all materials in the same proportion as they exist or will be used," the procedure states in the introductory "Scope" section. "Good sampling practices must be followed during the process of obtaining materials or products for testing. If the sample does not represent the true conditions of the material under consideration, the subsequent test results and analysis of data will be erroneous."

Asphalt industry representatives to the joint Caltrans-industry Rock Products Committee have been engaged in numerous meetings to discuss the practicality of how samples are collected and transported to labs for testing. Under the department's Quality Control-Quality Assurance programs, the contractor is responsible for the quality of the materials produced, and demonstrates that through proper testing reported to Caltrans.  

The department's assurance role involves making sure the

Boxed samples await testing.

contractor's facilities and personnel meet accepted standards, and through periodic testing of samples to ensure the department is independently verifying the contractor's test results.

Both Caltrans and industry agree that improper collection of samples can create problems with test results, and impact how much a contractor is paid for work, which is why CT125 is so heavily scrutinized. As Caltrans has moved to incorporate elements of the national "Superpave" initiative into its specifications, it has triggered discussions about how the language in CT125 should be updated.

In the case of asphalt, practical considerations of how samples are collected and handled in the field has been a hot topic of discussion. For example, "splitting" a sample actually may involve multiple steps, including re-blending the sample to ensure uniformity. How and where this is done can impact the test results.

Where samples are collected presents a whole new set of challenges: from the plant, from the mat behind the paving machine, from the windrow, or from the truck. Each method has its own peculiarities as well as advantages and disadvantages. The changes are even driving new advances in equipment. Click HERE to read last week's Asphalt Insider story abut a new sampling device created specifically for collecting asphalt samples at the plant.

CalAPA will continue to monitor the industry-agency meetings and will update members about any significant developments as they occur.

CalAPA is pleased to welcome our summer intern, Hamza Ali Shallwani, a U.C. Davis engineering student.

Born and raised in Pakistan, Ali Shallwani attended Headstart and Preparatory School Islamabad for his primary education. Growing up with his older brother in Islamabad, his parents always

Hamza Ali Shallwani

impressed upon him the importance of education. At age 10, he moved to London, for a year where he attended Argyle Primary School. He says living abroad for the first time molded his determination and curiosity of traveling and communicating with people of different ethnicities despite cultural barriers.

Two years later, he moved with his family to Buenos Aires, Argentina due to his father's job in the Embassy of Pakistan. He attended and graduated high school from Asociaci�n Escuelas Lincoln, the American international school of Buenos Aires, receiving his High School Diploma, and International Baccalaureate (IB) Diploma in addition to four Outstanding Class Awards for his leadership. 

Currently starting his sophomore year as a Civil & Environmental Engineering Major at the University of California Davis, Ali Shallwani hopes to expand his knowledge in the field through involvements in the Solar Decathlon 2015, American Society of Civil Engineers and his internship at CalAPA as he experiences the culture of California and living in the United States.

He will be performing various office duties, shadowing CalAPA professional staff and helping to conduct research for CalAPA publications.

"You have to re-earn your business every day."