What is Mass Concrete?

Mass concrete has revolutionized the way of construction. One can hardly believe a gigantic structure without using mass concrete. For some people, it may seem like a confusing concept and the following questions often come into the minds of people.

• What is mass concrete? And how is it different from other concrete?

In this blog, we will discuss everything about mass concrete.

Mass concrete, according to the American Concrete Institute's definition in ACI 207.1R, is "any volume of structural concrete in which the dimensions of the member being cast, the boundary conditions, the properties of the concrete mixture, and the ambient conditions can result in undesirable thermal stresses, cracking, harmful chemical reactions, or a reduction in the long-term strength as a result of elevated concrete temperature due to heat of hydration."

Mass Concrete Construction

As a result of a higher rate of the heat of hydration, mass concrete is described as big-volume concrete work with enormous dimensions and boundary conditions that is susceptible to rising temperatures.

In mass concrete, the hydration reaction generates a lot of heat. Lack of a suitable manner to dissipate this heat would increase the temperature difference between the mass structure's inner and outer surfaces, increasing the risk of thermal strains and cracks.

Also Read : Concrete Quantity Calculation in Circular Column

Mass Concrete vs Reinforced Concrete

• Since there is no one to support mass concrete in stress, it is weak.
• Most of the time, reinforced concrete is robust in both compression and tension. The grip generated between the steel and concrete is the cause.
• Mass concrete is typically utilized in the construction of structures when tension is not a crucial factor, while reinforced concrete is always used for building construction.
• Castings of beams, slabs, and columns can be seen to include reinforced concrete. In the ready-mix concrete facility, there is a lot of concrete.

Mass Concrete Temperature Control

ACI 301 Mass Concrete Temperature

• To avoid DEF, the maximum temperature in mass concrete after placement must not be more than 160 oF
• There cannot be a temperature difference of more than 35 oF between the placement's center and surface.
• To control thermal stress and cracking the temperature of concrete should depend on the selection of the materials, particularly the cementitious material content.
• Lowering temperature through pre-cooling of the components and post-cooling of the concrete.
• Construction management is the process of protecting a building against extreme temperature differences by being knowledgeable about the handling of concrete, construction scheduling, and construction techniques.

Type of cement used in mass concrete?

As per ACI 207.2R and 207.4R, the many types of cement that can be used to make mass concrete are listed. Some of the types of cement used for mass concrete building are Portland cement (ASTM C150), blended cement (ASTM C595), and hydraulic cement (ASTM C 1157).

Also Read : How To Prevent Concrete Formwork Failure

Water in Mass Concrete

The Portland cement's hydration process must not be adversely affected by any substances in the water used for mass concrete mixing. ACI 201.2R defines the maximum chloride concentration for water utilized for various construction tasks.

ACI 301-20, "Specification for Concrete Construction," and ACI 207.1R-05, "Guide to Mass Concrete," both contain additional information on mass concrete.

Parting Words

And that was all you need to know about mass concrete.

It surely revolutionized the way of construction and has given constructors new opportunities. It does have some cons but overall it is a great tool in the arsenal of a constructor.