Why Should C30/37 Concrete Class Be Preferred?

Concrete is a homogeneous mixture formed by mixing cement, aggregate, water, and additives. Initially, it has a workable consistency that can be shaped, and over time, it hardens, gaining strength and durability. Concrete is the most widely used material after water. Unlike traditional concrete production, ready-mix concrete plants produce concrete designed and manufactured with special automation programs. These concretes are classified according to their qualities, such as compressive strength and durability. Today, these specialized plants are capable of producing all concrete classes with the help of precise weighing units.

Concretes are classified according to the standards. These classifications, which summarize the durability of concrete, are commonly referred to by codes such as C16/20, C20/25, C25/30, C30/37, C50/50. The C code stands for “Concrete.” The first number of the concrete class represents the cylindrical compressive strength, while the second number represents the cube compressive strength. These codes are determined based on the average load the concrete can withstand per square centimeter. For example, a C20/25 cylindrical concrete sample can withstand 200 kilograms per square centimeter, while C30/37 cylindrical concrete can withstand 300 kilograms per square centimeter. The use of C30/37 as the lowest concrete class in load-bearing structures is increasingly common. Particularly in earthquake-prone areas, C30/37 concrete is considered highly necessary. Given that 70% of our country is located in the 1st and 2nd earthquake zones, it can be said that C30/37 should be the minimum concrete class used in structural concrete.

C30 concretes not only have higher load-bearing capacity but also, due to their water/cement ratios in their recipes, they are durable and impermeable, thus preventing corrosion and protecting the structural steel inside for a longer period, ensuring building safety. The water/cement ratio, as much as the amount of binder used in concrete design, also determines how affected the concrete will be by environmental factors. For instance, in cities like Istanbul or Izmir, to prevent corrosion from moisture or airborne chlorides, the water/cement ratio of the concrete used should not exceed 0.50. Moreover, since the raw materials, plant, and equipment required for its production are not different from those needed for low-strength concretes like C20/25, no special facilities or raw materials are necessary for producing C30/37 concrete. Thus, earthquake-resistant structures can be easily constructed using C30/37 concrete, which is resistant to both earthquakes and environmental factors.