1. This document describes an experiment conducted to determine the compressive strength of hydraulic cement. Cubes measuring 15 cm x 15 cm x 15 cm were created using a cement, sand, and water mixture and cured for 7 and 28 days. 2. The experiment followed standard procedures for mixing, pouring, and curing the cement cubes. The cured cubes were then tested in a compression testing machine to determine their compressive strength at 7 and 28 days. 3. The compressive strength results will indicate whether the cement mixture meets the requirements for its intended use in construction as a higher strength is generally required to support building loads.

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Soran University
Faculty of Engineering
Civil Engineering Department
STRENGTH OF HYDRAULIC
CEMENT
Student: Sarchia Khursheed
Group: 2
Experiment NO.: 5
Date: 16.12.2015
Supervisor: Arianfar Haji

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Introduction
Compressive strength of concrete (or cement) out of many test applied
to the concrete, this is the utmost important which gives an idea about
all the characteristics of concrete. By this single test one judge that
whether Concreting has been done properly or not. For cube test two
types of specimens either cubes of 15 cm X 15 cm X 15 cm or 10 cm X
10 cm x 10 cm depending upon the size of aggregate are used. For
most of the works cubical moulds of size 15 cm x 15cm x 15 cm are
commonly used.
This concrete is poured in the mould and tempered properly so as not
to have any voids. After 24 hours these moulds are removed and test
specimens are put in water for curing. The top surface of these
specimen should be made even and smooth. This is done by putting
cement paste and spreading smoothly on whole area of specimen.
These specimens are tested by compression testing machine after 7
days curing or 28 days curing. Load should be applied gradually at the
rate of 140 kg/cm2 per minute till the Specimens fails. Load at the
failure divided by area of specimen gives the compressive strength of
concrete.
Objective
The tests are required to determine the strength of concrete and
therefore its suitability for the job.
Apparatus
 The mould for making specimens for compression test of (0.5 X
0.5 X 0.5) in dimension.
 Balance with capacity at least 1000 g.
 Sieve No. 20 & 30.
 Water container.
 Mixing container.
 Spatula.
 Compression testing machine.
Materials

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 Cement sample
 Sand: Standard sand passing sieve No. 20 and retained on sieve
No. 30
 Drinking water
Procedure
1. The mix proportion (Cement: Sand) should be 1:3.
2. The amount of water should be 10% of total amount of dry
material.
3. Mixing the ingredient dry material with water for about 4 – 5
minutes.
4. Prepare the moulds and fixing the screw, then oil the internal
faces of the mould by a thin layer.
5. Fill the mould with 2 – 3 layer and compact each layer 25 blows
with a tamping rode.
6. Open the mould (demoulding) and put the specimen in a storage
tank (curing) at a standard temperature room (20 – 25 oC).
7. Keep the specimens for 3 – 28 days in a curing condition, then
take out the samples and put under the compression testing
machine.
Data and Calculations
Weight of the specimen = 72.8 g
Average compressive strength of the concrete cube (at 7 days) = …...
N/mm2
Average compressive strength of the concrete cube (at 28 days) = ……
N/mm2
Discussion
The strength of concrete increases with age. Concrete is used mostly
for structural purposes such as foundations, columns, beams and
floors and therefore must be capable in taking the loads that will be
applied (unless you’re just after a large paperweight!). One of the
methods of checking its fit for purpose is to carry out a concrete cube
test which measures the compressible cube strength of the concrete
and relates directly to the required design strength specified by the
designer. Also is it is usually a minimum requirement from the client to

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provide evidence of cube test results to ensure compliance with the
designers requirements.