Concrete Lab

Topics: Materials science, Tensile strength, Concrete Pages: 5 (880 words) Published: June 9, 2013
A H M 531
The Civil Engineering Center
Objectives:
To measure the mechanical stre
ngth of cement by applying
Compressive and Tensile tests on Cement-Sand mortar.
Standards:
¾
Compressive strength of cement using mortar cubes:
B.S.12 – Part 2
ASTM : C 109
¾
Tensile strength of mortar using briquettes:
B.S.12 – Part 2
ASTM : C 109
General Discussion:
In these tests (Compressive and
Tensile tests) we measured
the mechanical strength of the hardened cement.
These tests are done on cement – sand mortar and not on the hardened cement itself, the r
eason of not using neat cement
past on these test is in th
e following two points:
1. Difficulties in molding
(Getting good specimens).
2. Large variability of test results.
It is important that the resul
tant mixture (Cement + sand +
water) has the same properties
as concrete. So the standard
sand was chosen and the following properties were
determined to it:
1. Consist of pure siliceous material.
2. The particles are nearly spherical shaped.
3. The size of its particles
is smaller than 0.85mm (Pass
through 15 B.S. sieve) and bigger than 0.60mm (Retain
at 25 B.S. sieve).
A H M 531
Compressive and tensile strength of cement mortar
By: Ahmed Essam Mansour
The Civil Engineering Center
1
Visit www.AHM531.com for more lab reports and lecture notes! A H M 531
The Civil Engineering Center
In the cement-sand mortar, the proportion between Cement
and Sand is 1:3 and the W\C = 40%. The same mixture is used
in the compressive test a
nd in the tensile test.
Apparatus and Materials:
1. Pozzolan Cement.
2. Sweileh Sand.
3. Water.
4. Digital weighing scale, used to measure the weight of
cement and sand.
5. Glass graduates, used to m
easure the volume of water.
6. Cube moulds (three of them to make three specimens),
the dimensions of the cubes: 10*10*10. These cubes are
used to make compr
essive test’s specimens.
7. Briquette moulds (Three of them to make three
specimens), these moulds are used to make specimens
for the tensile test.
8. Glass plates.
9. Compressive testing machine.
10. Tensile testing machine.
11. Curing tank.
12. Mould Oil.
13.
Flat impervious sheet, used to cover the specimens to
reduce evaporating.
Procedures:
¾
Preparing the specimens:
1- Weighing 2220 grams of cement, 6660 grams of
sand and we mix them in the
dry condition first, till
the mixture seems to be homogenous.
2- We add 888 milliliters of water (That is from the
W\C=40%) to the mixture and keep mixing for 4.25 min.
A H M 531
Compressive and tensile strength of cement mortar
By: Ahmed Essam Mansour
The Civil Engineering Center
2
Visit www.AHM531.com for more lab reports and lecture notes! A H M 531
The Civil Engineering Center
3- Cover the interior faces of the Cube moulds and the
Briquettes with the mould oil so that Cement-Sand
Mortar won’t stick on the faces of the moulds.
4- We started in filling the cube moulds, the mould is
placed on a glass plate and then filled on three times
periods and in each period we tamp the mixture 25
times, on the last period we fill the mould with more
mixture than the needed qua
ntity and then tamp it till
the surface is leveled.
5- We fill the briquettes wi
th the same mixture, the
briquette is placed on a glass plate and then filled
with the mixture and tamp it using the thumb 12 times
on each face. And the 2 faces are leveled.
6- The Cube moulds and the Briquettes are then
covered with a flat impervious sheet to reduce
evaporating, and left for 24 hours in a humid
atmosphere and in moderate temperature.
¾
Removal of the moulds and curing:
On the next day (After 24 hour
s), we returned to the
laboratory and removed the Cubes and the Briquettes
of the specimens and then the specimens are marked
for identification.
The specimens should be placed in a water tube
which temperature should be 22 ºC for 7 days; this is
called “Curing”.
¾
Applying compression and tension:...
Continue Reading

Please join StudyMode to read the full document

You May Also Find These Documents Helpful

  • concrete compressive report Essay
  • Essay about concrete mixing equipment,concrete batching plant equipment
  • Essay on Pretensioning in Concrete
  • Concrete Research Paper
  • Lab Report on Reinforced Concrete Design Essay
  • Concrete Essay
  • Polymer Concrete Essay
  • Concrete and Mold Essay

Become a StudyMode Member

Sign Up - It's Free