Assignment 89
Delp10
normailconsistencyshow.ppsx
Eng.Anwaar AL-Suraij
Introduction
Building materials experiment
Materials
Cement
Reinforced bars
Bitumen
Fine aggregate & coarse aggregate
Mix design
Fish concrete
Structural building
Destructive Test
Non Destructive Test
Normal consistency and setting Time of Hydraulic Cement
Experiment #1
Eng.Anwaar AL-Suraij
Type of Mixing
Cement Past
Cement + water + Sand
Cement Mortar
Cement + Water + Sand + Aggregate
Concrete
Cement + Water + Sand + Aggregate + Reinforcement bars
Reinforced Concrete
Cement + water
Eng.Anwaar AL-Suraij
Normal consistency and setting Time of Hydraulic Cement
Introduction:
Portland cement is a finely ground powder composed of mineral compounds that react with water, set and harden.
Portland cement is a manufactured product and is composed of for four main components, which are:
Lime
Silica
Alumina
Iron
Eng.Anwaar AL-Suraij
There are five common types of Portland cement
Type I
Normal or ordinary Portland cement (Ordinary Portland Cement (OPC) is the most common cement used in general concrete construction
Type II
Moderate sulfate-resistant Portland cement
Type III
High early strength Portland cement
Type IV
Low heat of hydration Portland cement
Type V
Sulfate resistant Portland cement ( SRC)
Eng.Anwaar AL-Suraij
Type I
It is used for general construction purposes.
It is also used in most of the masonry works.
( Above ground level)
Eng.Anwaar AL-Suraij
Type II
For general use, more especially when moderate sulfate resistance or moderate heat of hydration is desired.
( underground structure but not high sulfate)
Eng.Anwaar AL-Suraij
Type III
It is used where concrete structures are subjected to high temperatures like workshops, refractory, foundries, etc.
It also used where the concrete is subjected to frost and acidic action.
( Time is important )
Eng.Anwaar AL-Suraij
Type IV
It is used for the construction of dam’s large footing, large raft slabs, and wind turbine plinths.
It is also used for the construction of chemical plants
Eng.Anwaar AL-Suraij
Type V
It is highly sulfate resistant
Frequently used in seawater construction
( Severe Sulfate in soli)
Eng.Anwaar AL-Suraij
Mix cement
To Preparation of cement paste
Use Mixer apparent
Place quantity of water ( Trial quantity)
Add 650 g of cement
Eng.Anwaar AL-Suraij
Vicat apparatus rod
Center the paste confined in the ring under the Vicat apparatus rod.
Adjust the apparatus to the zero mark when the rod is just touching the surface of the paste.
Release the rod and take the reading after 30s.
Vicat apparatus shall conform sizes requirement in ASTM C 187 – 04
Eng.Anwaar AL-Suraij
The cement paste shall be of normal consistency when the rod settles to a point 10 (+ or -1) mm below the original surface
Calculate the amount of water required for normal consistency as follows:
N.C.%=W*100/C
Where:
W = Weight of mixing water for 10 (+1 or -1) mm penetration
N.C. = Normal consistency
C = Weight of cement = 650 grams
Eng.Anwaar AL-Suraij
| Weight of water (gm) | Rod penetration (mm) |
| 148 | 4 |
| 150 | 5 |
| 152 | 8 |
| 154 | 12 |
Example :
In order to determine the N.C. of ordinary Portland cement sample, the following Vicat penetrations data were obtained. Calculate the normal consistency.
From the plot, the amount of water required to give 10-mm penetration is equal to:
W10 = 153 gm
W=153
Eng.Anwaar AL-Suraij
Vicat pentration versus amount of water
148 150 152 154 4 5 8 12Amount of water(gm)
Rod penetration (mm)
Normal Consistency test
Setting time of hydraulic cement test
Preparation of cement past sample to be qualified this sample
For anther test to acceptance or rejection of cement
Eng.Anwaar AL-Suraij
Setting time by Vicat apparatus
Experiment #1
Eng.Anwaar AL-Suraij
Setting time by Vicat apparatus
This method is used to determine the time of setting of hydraulic cement by means of the Vicat needle
The initial setting time: when the needle penetrates 25 mm into the paste and it is measured from the instant of mixing cement with water.
2. The final setting time: when the needle dose not sink visibly into the paste and it is measured from the instant of the mixing cement with water.
Eng.Anwaar AL-Suraij
Initial set. Occurs when the paste begins to stiffen considerably.
For construction purposes, the initial set must not be too soon
Final set. Occurs when the cement has hardened to the point at which it can sustain some load
For construction purposes, the final set must not be too late
Eng.Anwaar AL-Suraij
After tested the cement paste by normal consistency Place the cement confined in the conical ring in the moist room for 30 minutes.
Then determine the penetration at every 15 minutes thereafter.
Take the first reading at the zero time .
Vicat apparatus shall conform size of needle requirement in ASTM C 191 – 08
Vicat apparatus needle
Eng.Anwaar AL-Suraij
Example : In order to determine the initial and final setting time of ordinary Portland cement sample, the following Vicat penetrations data were obtained:
| Time (minutes) | Penetration (mm) | Time (minutes) | Penetration (mm) |
| 0 | 40 | 165 | 26 |
| 15 | 40 | 180 | 24 |
| 30 | 40 | 195 | 21 |
| 45 | 40 | 210 | 17 |
| 60 | 39 | 225 | 14 |
| 75 | 38 | 240 | 9 |
| 90 | 37 | 255 | 6 |
| 105 | 36 | 270 | 3 |
| 120 | 34 | 285 | 1 |
| 135 | 32 | 300 | 0 |
| 150 | 29 | -- | -- |
Determine the initial and final setting times?
Eng.Anwaar AL-Suraij
From the plot, the initial setting time at 25 mm penetration
Solution:
The final setting time at 0 mm penetration
=170 Minutes
= 300 Minutes.
Initial time =170 min
Final time =300 min
Eng.Anwaar AL-Suraij
Needle penetration versus time
0 15 30 45 60 75 90 105 120 135 150 165 180 195 210 225 240 255 270 285 300 40 40 40 40 39 38 37 36 34 32 29 26 24 21 17 14 9 6 3 1 0Time (minutes)
Needle penetration (mm)
Acceptance Criteria
ASTM C 150 specifies the following limits:
Minimum initial setting time is 45 minutes.
Maximum final setting time is 375 minutes
Eng.Anwaar AL-Suraij
