Page 27 - PH_Masonry_Final_Ver 1_July 2020

 The shape and texture of aggregate affects the properties of fresh concrete more than hard-

ened concrete. Concrete is more workable when smooth and rounded aggregate is used in-
stead of rough angular or elongated aggregate.

 The grading or size distribution of aggregate is an important characteristic because it deter-

mines the paste requirement for workable concrete. This paste requirement is the factor con-
trolling the cost, since cement is the most expensive component.

Classification Of Course Aggregates:

Well

Gap

Single-size
Course

Aggregates
Dense
Graded

Aggregates
Poor

Graded
(Uniform)

Open

Grading of aggregates:

The particle size distribution of aggregates is called grading. The grading determine the paste
requirement for a workable concrete since the amount of void requires needs to be filled by the

same amount of cement paste in a concrete mixture.

There are five typical range categories of aggregate grading:

Dense and well-graded aggregate

are desirable for making concrete, as the space between larger particles is effectively filled by

smaller particles to produce a well-packed structure.

Participant Handbook : Masonry 27