Slump testing makes quality concrete

KHOST PROVINCE, Afghanistan – More than 45 participants from 20 Afghan contracting companies attended a monthly contractor construction quality training, led by the Khost Provincial Reconstruction Team and Provincial Monitoring and Evaluation Team engineers at the Civil-Military Operations Center, downtown Khost province, Afghanistan, Feb. 20.

The training focused on concrete mixing and slump testing, a test that determines the consistency of concrete. The Khost PRT and PME team engineers decided that slump testing should be addressed after observing numerous faults in concrete consistency during site visits.

“The reason why slump testing is important is that it helps determine that the desired degree of workability is attained by running a series of trial batches, using various amounts of fine to coarse aggregate until a batch is produced that has the desired slump,” said U.S. Navy Builder 1st Class Iascc Baca, Khost PRT engineer.

After an introduction and overview by the Khost PRT engineers, the PME team engineers conducted the practical application portion. Since there were a large number of participants, the group was split in teams to mix the concrete to perform slump testing.

“It was a great opportunity for the PRT and Afghan engineers to interact in a relaxed and social environment, instead of being critical evaluators on site,” said U.S. Navy Master Chief Glenn Niemitalo, Khost PRT engineer. “It was great sharing ideas with peers and working with the personnel to create better practices.”   

According to the PRT engineers, slump tests are the easiest tests a contractor can perform on site. It allows the ability to field verify each concrete batch to ensure the crew is using the correct amount of raw materials. 
“Slump testing will minimize the chance of poor consolidation when a greater slump is required,” said Baca. “It will help to create strong concrete that has the potential to last for a long time.”

The course was a refresher for some engineers and a new learning experience for the junior engineers. Following the training, the engineers provided a slump test kit for each contractor company to use at their job sites.

“The session went extremely well,” said Baca. “The construction companies will definitely benefit from the lessons, and I look forward to working with the PME team in future sessions.”

Concrete mixing and slump testing is the first session of six to enable the transfer of responsibility to the PME team. The Khost PRT will provide oversight during the first three sessions, and the final three will be led by the Afghan engineers.

“The training provided a critical step to have the Afghan engineers assume responsibility for future training sessions,” said U.S. Navy Lt. Stephen J. Gustafson, Khost PRT lead engineer. “It enables trust in the PME team and builds rapport with their contractors.”

Next month’s training will concentrate on construction management. Other sessions will be determined upon future site visits.