QUANTITY SURVEYING
Engr. Conrado Baleña
Instructor
MASONRY
• Concrete Masonry Units also known as CMU are blocks used
in the construction industry to form a concrete block
structure like a wall or a fence.
• These are generally made up of concrete and aggregates of
certain design mixtures depending on strength required.
• In the Philippines, the Concrete Hollow Block (CHB) is the
most commonly used for masonry.
Most Common Concrete Blocks
1. Concrete Hollow Blocks
1. Concrete stretcher block
2. Pillar block
3. Jamb block
4. Lintel Block
2. Aerated Autoclaved Concrete Block (AAC)
3. Concrete Bricks
4. Solid Concrete Blocks
5. Paving Blocks
Concrete Hollow Blocks (CHB)
Concrete Hollow Blocks (CHB)
• Commonly used in the construction industry
• CHBs are usually manufactured using lightweight aggregates
with a certain design load depending on the nature of the
member it will be used into.
• CHBs have voids of ¼ its gross area and the solid area should
be not less than half of its area to attain its maximum
allowable load capacity, study suggests.
• The voids are generally filled with mortar of lightweight
aggregate material as well.
Types of CHBs
• Load bearing blocks
– are pre-cast in molds and compacted with the aid of vibration, or
molding machines involving the use of compressed air, or a
combination of both.
– They are usually made of concrete comprised of cement an
aggregate.
– thickness ranges from 15 to 20 cm and are used to carry load aside
from its own weight.
• Non-load bearing blocks
– are blocks intended for walls, partitions, fences, dividers and the like
carrying its own weight whose thickness ranges from 7 to 10 cm.
Concrete Hollow Blocks (CHB)
• Hollow concrete blocks come in a variety of
sizes, such as:
– 100 mm x 200 mm x 400 mm,
– 150 mm x 200 mm x 400 mm, and
– 200 mm x 200 mm x 400 mm.
• These blocks are most commonly gray but
can also be found in different colors,
including tan and dark red.
Stretcher block
• Concrete stretcher blocks are used in construction to connect the
corner of masonry units. Their faces are laid parallel to the face of
the wall.
• These concrete blocks come with reinforcing bars and approved
mortar and paste or adhesive material.
Pillar block
• Pillar blocks are most often used to build pillars or piers.
• They’re also called double corner blocks and are designed so that
both ends could be left visible.
• Pillar blocks are the kind of blocks many people think of when
they think of concrete blocks, and they are often available in large
quantities at building supply stores.
Jamb Block
• Jamb blocks are made with a shallow groove across the two
holes and a deeper groove at one end.
• They provide space for the casing members of a window and
are often used specifically in double-hung windows.
Lintel Blocks
• They are used in preparation for lintel beams. These lintel
blocks are manufactured in such a way that it serves as a
masonry unit and a formwork itself.
• Aesthetically, lintel blocks have a deep groove where
reinforcing bars are put along with the concrete. Meaning,
they serve as permanent formwork systems for the lintel
beam member. This is found to be efficient and useful by
most builders as they served two different purposes. A two
in one product it is.
Lintel Blocks
Aerated Autoclaved Concrete Block
(AAC Blocks)
• Used mostly for exterior walls.
• AAC is well suited for high-rise buildings and those with high-
temperature variations.
• It is porous, non-toxic, reusable, renewable, and recyclable.
• Due to its lower density, high-rise buildings constructed
using AAC require less steel and concrete for structural
members.
• The increased thermal efficiency of AAC makes it suitable for
use in areas with extreme temperatures, as it eliminates the
need for separate materials for construction and insulation,
leading to faster construction and cost savings.
Aerated Autoclaved Concrete Block
(AAC Blocks)
Concrete Bricks
Concrete bricks
• are small rectangular block arranged and piled systematically
to create a rigid wall.
• are usually made up of cooked clay or concrete.
• Some manufacturers use solid concrete while others play
with its cement and aggregates ratio for economic purposes.
Other manufacturers also created bricks with different color
as per request of some clients.
• Concrete bricks are usually used in fences, facades, as it
provides the good aesthetic and slick look.
Solid Concrete Blocks
• Way denser and bigger than concrete bricks, solid concrete
blocks are manufactured to be strong, heavy, and created
out of naturally dense aggregates.
• These solid concrete blocks are strong enough that it is used
for large masonry units that are load-bearing in nature.
• Solid concrete blocks are just similar to concrete brick but
are way costlier and heavier and can withstand more forces
as compared to bricks.
Paving Blocks
• Paving Blocks are generally just a rectangular or square box
made up of reinforced concrete.
• used in paving and road shoulders, these have to be painted
with high-visibility concrete paints so motorists and drivers
could see it right away.
• They have to be rigid and firm enough to receive any car
collisions.
• also used in parks, walkways, and parking areas.
Paving Blocks
Topic Outline
1. Concrete Hollow Blocks
2. Cement and Sand for block laying
3. Cement, sand and gravel filler for the hollow core or cell
4. Cement and fine sand for plastering
5. Cement, sand and gravel for foundation or footing
6. Reinforcing steel bars *
7. Tie wires *
*to be discussed in next chapter – Metal Reinforcement
Illustration 2-1
A concrete hollow block wall has a general dimension of 3 m high and 4 m
long.
SOLUTION 1 – By Fundamental Method
1. Divide the height of the fence by the height of one block
2. Divide the length of the fence by the length of one block
3. Multiply the result of step 1 by step 2
SOUTION 2 – By the Area Method
1. Compute the area of the fence
2. Multiply the area by 12.5.
1 1/2
6
2 7
12
3 8
4 9
11
5 10
Illustration 2-2
Find the number of 200 mm x 200 mm x 400 mm concrete hollow blocks
to construct the fence.
SOLUTION 1 – By Fundamental Method
1. Divide the height of the fence by the height of one block
2. Divide the length of the fence by the length of one block
3. Multiply the result of step 1 by step 2
SOUTION 2 – By the Area Method
1. Compute the area of the fence
2. Multiply the area by 12.5.
Illustration 2-3
Illustration 2-3
From the figure in illustration 3, using class B mixture , find the number
of:
1. 20 x 20 x 40 cm concrete hollow blocks
2. Cement, sand and gravel for concrete for the posts and footings
3. Cement Mortar for CHB
4. Cement Mortar for Plastering
Solution 1:
Finding the CHB
a) Find the perimeter of the wall
b) Find the space length occupied by the posts
c) Subtract (b) from (a)
d) Multiply by the height of fence to get Net Area
e) Multiply by 12.5 to get the total number of concrete
hollow blocks
Solution 2:
Concrete Posts and its Footing
a) Find the volume of one concrete footing lab
b) Find the volume of 16 footings
c) Find the volume of 16 concrete posts
d) Find the total volume of concrete posts and its footing
e) Refer to Table 1-2. Using class “B” concrete under column
40 kg cement, find the quantity of cement, sand and
gravel.
Solution 3:
Cement Mortar for CHB – Volume Method
a) Determine the volume of mortar in between the layer of
the blocks adopting 12 mm or 0.12 m uniform thickness of
the mortar.
b) Find the volume of mortar between all the layers of CHB
• Find the number of layers of block by dividing the wall height
by the height of one block.
• Multiply the number of layers by the volume of mortar.
c) Find the volume of hollow cores per block.
d) Find the total volume of hollow core for the total number
of CHB.
e) Find the total volume by adding (b) and (d)
f) Refer to Table 2-1. Using class “B” mixture, find the
quantity of Cement and Sand
Solution 3:
Table 2-1 Quantity of Cement and Sand for Mortar and Plaster in
Cubic Meter
Class Cement in Bags Sand
Proportion
Mixture 40 kg 50 kg m3
A 1:2 18.0 14.5 1.0
B 1:3 12.0 9.5 1.0
C 1:4 9.0 7.0 1.0
D 1:5 7.5 6.0 1.0
Solution 3:
Cement Mortar for CHB – Area Method
1. Find the area of the wall
2. Refer to Table 2-2. Along 20 x 20 x 40 CHB under class “B” mixture,
find the quantity of Cement and Sand
Table 2-2 Quantity of Cement and Sand for CHB Mortar per Square Meter
Bags Cement Mixture
Size of CHB Number per
in cm m2 Sand
A B C D
(m3)
10 x 20 x 40 12.5 0.792 0.522 0.394 0.328 .0435
15 x 20 x 40 12.5 1.526 1.018 0.763 0.633 .0844
20 x 20 x 40 12.5 2.260 1.500 1.125 0.938 .1250
Solution 3:
Cement Mortar for CHB – Hundred Block Method
1. Find the number of CHB
2. Convert to unit of 100
3. Refer to Table 2-3. under Class “B” mixture for a 20 x 20 x 40 CHB ,
find the quantity of Cement and Sand
Table 2-3 Quantity of Cement and Sand for CHB Mortar per Square
Meter
Bags Cement Mixture (40 kg)
Size of CHB in
cm Sand
A B C D
(m3)
10 x 20 x 40 6.336 4.176 3.152 2.624 0.348
15 x 20 x 40 12.150 8.104 6.072 5.064 0.675
20 x 20 x 40 18.072 12.000 9.000 7.504 1.000
Solution 4:
Cement Mortar for Plastering – Volume Method
a) Find the area of the two sides of the wall
b) Assuming that the plaster is 16 mm average thickness, determine the
volume of the plaster
c) Refer to Table 2-1. Using 40 kg cement class “B” find the quantity of
cement and sand.
Table 2-1 Quantity of Cement and Sand for Mortar and
Plaster in Cubic Meter
Class Cement in Bags Sand
Proportion
Mixture 40 kg 50 kg m3
A 1:2 18.0 14.5 1.0
B 1:3 12.0 9.5 1.0
C 1:4 9.0 7.0 1.0
D 1:5 7.5 6.0 1.0
Solution 4:
Cement Mortar for Plastering – Area Method
a) Find the area of the two sides of the wall
b) Refer to Table 2-4. Under 16 mm thick plaster class “B” mixture, find
the quantity of cement and sand.
Table 2-1 Quantity of Cement and Sand for Mortar and
Plaster in Cubic Meter
Cement in Bags
Class Thickness of Plaster
Mixture
8 mm 12 mm 16 mm 20 mm 25 mm
A .144 .216 .288 .360 .450
B .096 .144 .192 .240 .300
C .072 .108 .144 .180 .225
D .060 .090 .120 .150 .188
Sand .008 .012 .016 .020 .025
