The document summarizes a site tour of an Al Saeed ready mix concrete plant. It describes the raw materials used - coarse aggregates like basalt, fine aggregates like sand, water, and admixtures. It explains the testing done on aggregates including impact, abrasion, and sieve analysis tests. The concrete production process is outlined involving storing materials, mixing in a machine, slump testing, and curing cube samples. The tour provided insight into equipment, strength testing, and benefits of ready mix concrete and sandwich blocks.
1. Adnan Mohammed Alqaramani | reinforced Concrete Design 1 | March 28, 2022
Site Tour
AL SAEED READY MIX CONCRETE
2. PAGE 1
The content
INTRODUCTION
READY MIX CONCRETE
RAW MATERIAL: coarse, fine aggregates & water
ADMIXTURES
PROCESS
SLUMP TEST FOR CONCRETE
TEST FOR CUBE
EQAUTIONS
BLOCK SECTION
BENEFITS OF THE TOUR
3. PAGE 2
INTRODUCTION
Al Saeed ready mix concrete plant is considered to be one of the best leading company in
construction works in Yemen. We as groups went to Al Saeed, dated Mon, March 12, to
know and understand the process of the plant, the raw materials and admixtures in real
life. The location of Al Saeed plant is Hezyaz, Sana'a, Yemen.
READY MIX CONCRETE
Ready mix concrete, popularly known as RMC is playing a vital role in the building
construction. Invention of concrete brought a revolution in the building construction.
Samwise invention of RMC now become an integral part in construction of high raised
buildings, bridges, pre-stressed concrete, beams, and road work.
The major advantage of RMC is; concrete can be produced at various strength to suit the
specific requirements of structural stability. Not like conventional cast in situ concrete.
The RMC can be produced inn large quantity at a time and the quality can be monitored
closely.
RAW MATERIAL: coarse, fine aggregates & water
The raw materials required for the preparation of RMC are coarse aggregate, fine
aggregate, and water.
A. Coarse Aggregate: The Factory used cursed Basalt that has angles and sizes of 1/2-
inch, 1/8-inch, 1/4-inch. Why they used Basalt as a coarse aggregate not any other
material? The reason behind that is because Yemen is very rich of this kind of stones
as it is founded in mountains as big rocks, they crush them and makes various sizes of
coarse aggregates. The second reason is because of the high strength of the basalt and
it absorb less water and is not affected by moisture.
The use of the three sizes in the mix is to provide higher density to the concrete with
less voids in the concrete.
Test for coarse aggregate: we have Abrasion test and Impact test
4. PAGE 3
IMPACT TEST:
Aggregate may be subjected to a sudden shock or impact
during as well as after the construction. These loads are
different from the gradually applied compressive loads.
Due to such kind of loads, aggregate breaks down into
smaller pieces. In order to evaluate the resistance to
impact of aggregate, the aggregate impact test is
conducted. Aggregate impact value gives the idea about
how much impact load can be resisted by aggregate.
Actually, aggregate should be sufficiently tough to resist
their disintegration due to impact. This distinctive
property is measured by impact value test.
A photo shown the impact machine
ABRASION TEST: (LOS ANGLES MACHINE)
The Los Angeles abrasion testing machine consists of a circular drum mounted on a
horizontal axis; so that, it can be rotated. The steel balls are placed in the drum along with
the sample of aggregates. The drum is then rotated depending upon the gradation of
aggregates. After
rotation, the material is
sieved through a 1.7
mm sieve and the
difference between the
initial weight and the
final weight (sieved
weight) is calculated.
The result is expressed
as %, and this value is
called Abrasion value
of aggregate.
B. Fine Aggregate: is generally natural sand that has different sizes but after going
through the sieve analysis test it becomes at one size. The test of the fine aggregate is
sieve analysis test, which actually get rid of large or big rock in the sand.
5. PAGE 4
Benefits of sand in
concrete is to bind
everything together and
make s artificial rock.
The sand also enhances
concrete's most favorable
properties such as
thermal expansion,
compression strength,
and tensile strength.
This kind of test is also
used for gravel
A picture that identify the sieve analysis test and
sizes of sieves
SAND EQUIVALENT TEST
The sand equivalent test quantifies the relative abundance of sand versus clay in soil. The
test is used to qualify aggregates for applications where sand is desirable but fines and
dust are not. A higher sand equivalent value indicates
that there is less clay like fig. 1. The sand actually
contains about 14% dust.
Fig. 1 shows the percentage of clay or
dust on the sand
6. PAGE 5
WHY IS IT NECESSARY TO TEST AGGREGATES?
The aggregates are tested to determine their properties like ..
Toughness
Strength
Hardness
Shape
Water Absorption
C. WATER
The water used for mixing concrete must be drinkable water not dust or polluted water. It
must be clean or totally out of salt so with that said, sea is not used to mix concrete that is
because sea has high salt percentage which affects the concrete. The water used for
concrete must be adequate to the mix design of the plant and also, they consider the
climate effects around the plant. For example, if in hot weather cube of ice or freezer is
used to keep the water cold and in return when all ingredients are being mixed the
temperature of the concrete must be 50F to 90F 9 (10C to 32C). The temperature of the
concrete before it is cast should be 35K.
Before all the raw materials used for the ready
mix concrete it, they must go through truck
scale to know the amount of aggregates inside
the truck.
7. PAGE 6
Admixtures
Concrete admixtures are used to improve the behavior of concrete under a variety of
conditions and are of two main types: Chemical and Mineral.
Chemical admixtures reduce the cost of construction, modify properties of hardened
concrete, ensure quality of concrete during mixing/transporting/placing/curing, and
overcome certain emergencies during concrete operations.
Types of Chemical Admixtures
set retarders can delay the setting time of concrete mixing materials
set accelerators shorten the time of setting and increase the rate of early strength
development
Superplasticizers used to reduce water by over 25%
Types of Mineral Admixtures
Mineral admixtures affect the nature of the hardened concrete through hydraulic or
pozzolanic activity. Pozzolans are cementitious materials and include natural pozzolans
fly ash and silica fume.
Silica is used to meet high strength and low permeability. Increased compressive and
flexural strengths, and increase durability.
All material are stored in open area with a hunger to prevent the sun heat on the raw
materials
8. PAGE 7
Photos that show how sand and gravel are stored in an open area
A photo shows how raw materials are stored before the transmit into the belts and then to
the main unit
9. PAGE 8
PROCESS
The raw materials coarse aggregate and fine aggregate are normally stored in open area
and the cement, which is brought to the plant by truck, is stored in silos. The concrete
mixed machine is generally mounted at the center and the raw materials are stacked in the
surrounding area like a heap. The cement is conveyed to the machine by pneumatic
conveyors/ screw pumps and the coarse and fine aggregate are loaded into machine using
bucket elevators (scrappers). Water is stored in sump and the same is pumped into the
mixer machine through pipes. All the raw materials are loaded into the machine based
upon the strength of the required concrete and allowed for mixing using water. After
certain period, the homogenized mixture of concrete is loaded into trucks with required
consistency. To maintain the slump (consistency and workability) admixtures are added.
All these activities are controlled by centrally located computer aided operating system.
A picture that shows all the things inside the plant
Silos for Cement
Containers of
Raw Materials
Bucket Elevators
The Homogenized
Mixture
10. PAGE 9
SLUMP TEST FOR CONCRETE
The concrete slump test measures the
consistency of fresh concrete before it
sets. It is performed to check the
workability of freshly made concrete,
and therefore the ease with which
concrete flows. The slump testis used
to ensure uniformity for different loads
of concrete under field conditions.
Very dry mixes: having slump 0 –25
mm, are typically used in
constructing pavements or roads.
Low workability mixes having
slump 10 – 40 mm, are typically
used for foundations with light
reinforcement. Medium
workability: mixes with slump50 –
90 mm, are typically used for
normal reinforced concrete placed
with vibration. High workability:
concrete with slump > 100 mm is
typically used where reinforcing
has tight spacing.
TEST FOR CUBE
The compressive strength of the concrete cube test provides an idea about all the
characteristics of concrete. By this single test one judge that whether Concreting has been
done properly or not. Concrete compressive strength for general construction varies
from15 MPa to 30 MPa and higher in commercial and industrial structures. Compressive
strength of concrete depends on many factors such as water-cement ratio, cement
strength, quality of concrete material, quality control during the production of concrete.
Test for compressive strength is carried out either on a cube.
11. PAGE 10
In general, compressive strength means the ability of material or structure to carry the
loads on its surface without any crack or deflection. A material under compression tends
to reduce the size, while in tension, size elongates.
The test is called compressive strength of cube 150*150*150mm to know the strength of the concrete after
7, 14, and 28 days.
A photo shows the compressive machine and cube dimensions 150*150*150mm
Why cubes are tested at 7, 14 and 28 days for the Compressive Test?
First 28 days strength is the dentition of compressive
strength. Therefore, it is obvious to test concrete on 28 days
for strength. Concrete reaches 99% of its full potential
strength in 28 days (4 weeks). The reason for testing
concrete before 28 days on these days as well is that
suppose the concrete strength falls inadequate on 7 or 14
days. Then, the concrete may straight away be discarded or
another mix design be made. That is why generally three
tests are done during the 28-days.
12. PAGE 11
EQAUTIONS
After the cube reached its maximum strength, it started to cracks.
Maximum load: 763.370 KN
Area of cube: 0.15 * 0.15 * 0.15 in height
𝑓`𝑐 = 𝛿 =
𝜌
𝑎
𝑓`𝑐 =
763.370×1000
150×150
= 33.92 𝑀𝑃𝑎
A photo that shows the time needed until concrete start collapse
13. PAGE 12
BLOCK SECTION
Alsaeed plants also have made a block, which is very useful. It is called Sandwich Block
Sandwich block is a system that protects the buildings from external factors and provides
the utmost convenient and economical solution for them to have a powerful stand.
Benefits:
1- light and durable construction elements
2- sandwich blocks are used to clad roofs and external walls of the buildings as well
as achieving insulated internal walls and cold storages
3- Sandwich blocks, protecting you against the external factors on all sides of your
building.
They are produced by filling in a thick and low-density insulation material between two
thin and high-density metal surfaces.
14. PAGE 13
BENEFITS OF THE TOUR
I learned more about raw materials, and types of admixtures chemical and
mineral additives. In addition, how they affect the properties of RMC
I learned that raw materials have to go through several steps before it is used
in the ready mix concrete like the tests for sand: sieve analysis and
equivalent test to know the dust percentage exited in the sand. The test for
gravel: impact test and Los angles test.
Water used for mix must be drinkable and clear from dust. HP of water has
to be 6 or above. It must be cool water not hot just in some cases it is
allowed to use it. Moreover, other cases we use frizzed cube to moderate the
temperature of the mix
This kind of test are used to know the strength of the gravel. Knowing the
strength of the gravel shows how strong the concrete will be. I also learned
that gravel is crushed to very sharp angles to bind greater than the smooth
gravel.
I understand more about the behavior of concrete. How it is treated when
mixing, casting, and curing. I learned more about the strength of concrete
and the calculation for it and how to find the F`c for the concrete. I
understand that RMC must be checked before it leaves the plant and before
it casts in situ. They must check for the temperature of the RMC. The have
to use the Slump test to know the workability of the concrete (know the ratio
of water.). I learned that concrete after cast it needs to be tested in several
days and that is to know the higher strength the concrete will get. The
concrete reach to 99% of its strength in 28 days. Moreover, it increases after
5 years to 105%.
I have the main idea of how the plant work in general. How things go just
perfect and in time. How materials are transited to the machine and how
CAD takes orders.
