I’m curious as to why ACI 318-08 Section 5.6.2.41 states that at least three test cylinders are required to define a strength test using 4 x 8 in. (100 x 200 mm) cylinders (4 x 8s) but only two test cylinders are required to define a strength test using 6 x 12 in. (150 x 300 mm) cylinders (6 x 12s). I work near Chicago, and we place a lot of concrete and fireproofing when the ambient temperature is between 0 and 20°F (–18 and –6°C). We just started using the smaller cylinders and have been having poor compressive strength results.

Celebration in his honor held during Spring Convention.

Unfortunately, little essential knowledge and understanding of concrete are considered in the majority of engineering degree or diploma programs in India. As a result, engineers who join the industry have to acquire concrete-related experience in the field and through continuing education. This lack of training created a great need for a structured program to train and certify concrete practitioners in various aspects of concrete and related activities. Luckily, that program exists in the form of ACI certification.