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civil techniques

Moisture Content By Rapid Moisture Meter

abbu riyaz 1 May, 2023

Moisture Content By Rapid Moisture Meter is use to determine the Moisture content / water content in soil sample. It is a mobile system for measuring large verities of materials like soil, aggregates,etc.

With this rapid moisture meter the Moisture content / water content determines quickly. It determines by the gas pressure of Calcium Carbide using in it. The Calcium Carbide reacts with water in the sample. And it forms Acetylene gas. This increase the pressure inside the vessel.

The Moisture content / water content percentage observes in the dial gauge. And calculations computes to determine the moisture content / water content in soil sample.

Moisture Content By Rapid Moisture Meter

The Rapid Moisture Meter consists of various tools in it. The main components of a Rapid Moisture Meter are given as follows,

A Pressure Vessel made of steel with a Dial gauge at top of it.
Metallic sealing cup
Digital weighing machine (or) Counter Balance
Steel balls of two different sizes
Calcium Carbide
Standard Scoop
Spoon
Cleaning Brush

1. Pressure Vessel

Rapid Moisture Meter consists of a pressure vessel made of metallic body. It is built with a metallic body to withstand the high pressure obtains inside it. And it consists of a dial gauge at one end of the pressure vessel. The moisture content / water content determines with the reading observes in the dial gauge.

2. Metallic sealing cup

The other end of the pressure vessel contains a hollow space. This space seals with a metallic sealing cup. This sealing cup is built up of metal to withstand the pressures obtains inside it. The entire reactions of the chemical and soil samples takes place inside the hollow space in pressure vessel.

3. Digital weighing machine (or) Counter Balance

The Rapid Moisture Meter consists of a digital weighing scale or a counter balance. This use to measure the mass of soil sample.

4. Steel balls

It consists of two different sizes of steel balls in it.

12.5 mm
25 mm

It has three 12.5 mm diameter Balls and one 25 mm diameter ball.

5. Calcium Carbide

The main element in the rapid moisture meter is Calcium Carbide. It acts as an Absorbent. It is mix with the soil sample along with steel balls inside the pressure vessel.

The Calcium Carbide reacts with water in the sample. And it forms Acetylene gas. This increase the pressure inside the vessel.

6. Standard Scoop

A Standard scoop use as a balancing tray to hold the soil samples in counter balance.

7. Spoon

A small Spoon use to take calcium carbide from container and to fill the hollow space of the pressure vessel.

8. Cleaning Brush

A Cleaning brush uses to clean the hollow space in the pressure vessel. It removes the dirt and remaining particles of calcium carbide and soil sample present inside the pressure vessel.

civil techniques

Model Calculation of Soil Compaction using Core Cutter Method

abbu riyaz 1 May, 2023

Model Calculation of Soil Compaction using Core Cutter Method is discussed in this post. Soil Compaction using Core Cutter Method is use in construction field to determine the Field dry Density, Bulk Density and compaction of soil. It is use to identify the dry density of the compacted or dry fine grain soil which is free from the aggregates.

Model Calculation of Soil Compaction using Core Cutter Method

For Calculation of Soil Compaction using Core Cutter Method some important parameters has to be derived. That important parameters are as follows,

Volume of Core Cutter
Weight of Core Cutter
Weight of Core Cutter + Weight of Soil
Soil Weight
Bulk Density
Moisture content or Water Content
dry Density and
Maximum dry Density

1. Volume of Core Cutter (Vc)

The Volume of Core Cutter refers to the volume of cylinder.

Volume of Core Cutter = Volume of cylinder.

Vc =π r² x h Vc = 3.14 x 50² x 130 = 1020.5 cm³

(or)

Vc = πd²/4 x h Vc = 3.14 x 100²/4 x 130 = 1020.5 cm³

2. Weight of Core Cutter (Wc)

Measure the weight of Core Cutter from a calibrated Weighing balance machine and note as Wc. And it is taken in grams.

Wc = 1100 g

3. Weight of Core Cutter + Weight of Wet Soil (Ws)

The weight of Core Cutter + weight of soil measures from Weighing balance machine and noted as Ws. And it is taken in grams.

Ws = 3252

4. Soil Weight (Wa)

The weight of soil (Wa) derives from ( Ws – Wc )

(Wa) = (3252 – 1100)

(Wa)= 2152

5. Bulk Density (Yb)

Bulk Density derives from the formula,

(Yb)=(Ws-Wc / Vc)

Yb =( 3252 – 1100 / 1020.5)

(Yb) = 2.10

where,

Wc = weight of Core Cutter,

Ws = weight of Core Cutter + weight of soil

Vc = Volume of Core Cutter

6. Moisture Content / Water Content (W) %

The Moisture Content / Water Content of the wet soil determines from Rapid Moisture Meter. The moisture/water content of wet soil derives from the formula,

W= (M/100-M) x 100

where,

M = Moisture Meter Reading ( M= 4 )

W = (4/100-4) x 100

W = 4.16 %

The moisture/water content is taken in Percentage.

7. Dry Density (Yd)

(Yd)= (100 x Yb / 100 + w)

where,

Yb = Bulk Density,

W = Moisture Content / Water Content

( Yd ) = 100 x 2.10 / 100+ 4.16

= 2.01

8. Maximum Dry Density

The maximum value of Dry Density is taken and it is noted in grams.

MDD = 2.01

9. Compaction Percentage

Compaction Percentage calculates by dividing the dry density by maximum dry density.

Cp % = Dry Density / Maximum Dry Density

2.01/2.01 = 100 %

Table for Calculation of Soil Compaction using Core Cutter

Method

OBSERVATION SHEET
DETERMINATION OF DRY DENSITY OF SOIL (CORE CUTTER METHOD)
PROJECT:-
LOCATION :-
TESTED BY:-
SI No	Observation and Calculation	Determination
SI No	Observation and Calculation	I	II	III
1	Volume of core cutter (Vc), cm3	1020.5	1020.5	1020.5
2	Weight of core cutter (Wc), g	1100	1100	1100
3	Weight of core cutter + Wet soil (Ws), g	3252	3141	1391
4	Weight of wet soil (Ws-Wc), g	2152	2041	2091
5	Bulk Density, Yb = ((Ws-Wc)/Vc)), g/cm3	2.10	2.0	2.04
6	(Rapid Moisture Meter) Water content (w),%	4.16	4.16	4.16
7	Dry Density, Yd = (Yb*100/(100+w)), g/cm3	2.010	1.92	1.95
8	Max. Dry Density, (g/cm3)	2.010	2.010	2.010
9	Compaction Percentage, % (DD/MDD)	100%	95.5%	97%
Average Dry Density, Yd = 97.5 %

Concrete

Concrete Sleepers

abbu riyaz 1 May, 2023

Concrete Sleepers introduces in the modern construction of railway tracks. Mainly sleepers are of concrete, timbers, steel, cast iron. In thees various types of sleepers, due to need for better design and economy of sleeper on sustainable basis Concrete Sleepers engages.

These are the members which lay transverse to the rails on which the rail supports and fixes. Sleepers are concrete beds in the railway tracks. The main role of sleepers is to transfer load from rails to the ballast. And the sub-grade below. It as a transverse member throughout the permanent way.

Concrete Sleepers

It is using more than any other sleepers because of its unique properties. They are more resistant to wear and tear. It withstands blows and vibrations cause due to heavy moving loads. And it is fewer subjects to chemical attacks, termite attacks, and more corrosion resistance.

There are two types of sleepers they are,

Reinforced and
Pre-stressed Concrete sleepers

Concrete is the best and suitable material for sleepers in railway tracks. Some of the main and important features are as follows,

It is a strong and homogeneous material
Not affect by moisture
Unaffected by chemical attacks
High resistance to wear and tear
Unaffected by sub-soil salts

Advantages of Concrete Sleepers

It is having a maximum life compare to other sleeper forms.

No difficulties in the track circuiting.

Not affect easily by moisture, termites, white ants, insect attacks.

Having a high load carrying capacity.

High tendency to absorb shocks and vibrations.

Withstands wear and tear due to heavy moving loads.

Disadvantages of Concrete Sleepers

Weight is high compared to other types of sleepers.

It requires more fittings like pads, plugs,etc.

In derailment of sleepers the damages are very heavy.

After the life completes it is not re-usable therefore the scrap value is low.

Construction materials

Metal Sleepers Advantages and Disadvantages

abbu riyaz 1 May, 2023

The Metal Sleepers Advantages and Disadvantages are discussed in this post. Railway Track Sleepers are members which lay transverse to the rails on which the rail supports and fixes. Sleepers are beds in the railway tracks. The main reason to use metal sleepers replacing wooden sleepers are because of insufficiency of wooden sleepers. Metal sleepers use widely in the modern construction of railway tracks. The main role of sleepers is to transfer load from rails to the ballast. The Metal sleepers are of cast iron and steel.

These sleepers fix vertical to each other. It fixes throughout the track. The main work of sleepers is to hold rails in a strong position. It receives the loads from rails and spread to ballast and sub-grades. In these various types of Metal sleepers, the sleeper which is economic uses in the construction of railway tracks. Even though it use mostly in the modern construction of railway rail track it posses many advantages and disadvantages.

Metal Sleepers Advantages and Disadvantages

Advantages

There are many important advantages of metal sleepers. The main advantages of metal sleepers are as follows,

Metal sleepers are uniform in strength and durability.
For metal sleepers no frequent renewal requires.
It is economical and have longer life.
Low maintenance and easier repair.
Gauges are easy to maintain and adjustable.
Easy in manufacturing and laying.
The fitting operation is better and it makes less occurrence of creep.
It is fireproof.
It is reusable and have a good scrap value.
The manufacturing of sleepers is a simple process.
The fixtures of the sleepers are less in number and simple in nature.

Disadvantages

Metal sleepers having many good advantages still it posses some disadvantages in it. The disadvantages of metal sleepers are as follows,

More ballast requires for metal sleepers
Difficult to maintain due to rust and other chemical gents in atmosphere.

And it is more likely subjects to corrosion/rusting.
As a good conductor of electricity it interferes with track circuiting.
It is not suitable for level crossings and bridges.
Unsuitable in case of pointing.
Creep occurs frequently.
It subjects easily to deform and bend due to heavy moving loads in it.
Suitable only for stone ballasts.
Cracks develop easily in metal sleeper seats through the holes of bolts.
More care has to take to maintain steel sleepers.

The Metal Sleepers Advantages and Disadvantages are considering to handle the difficulties in the construction of modern railway rail tracks.

civil techniques

Types of Metal Sleepers

abbu riyaz 1 May, 2023

There are many Types of Metal Sleepers using in the construction of railway rail tracks. As it satisfies all the needs of a sleeper it is using mostly in the construction of railway rail tracks.

Types of Metal Sleepers

There are many Types of metal Sleepers using in the construction of railway rail tracks. The following types of Metal Sleepers are as follows,

Cast iron Sleepers and

Steel Sleepers

1. Cast iron Sleepers

The Cast iron sleepers are using widely in the construction of railway rail tracks. Cast iron are of many types as follows,

Bowl or Pot sleepers
Plate sleepers
Box sleepers
C.S.T-9 sleepers
Rail Free Duplex sleepers.

Bowl or Pot sleepers

It consists of two bowl or pots placed inverts on ballast. The main feature of these sleeper are, that it is on the top of pot a rail seat or a chair provides to hold the flat footed and Bull headed rails.

Plate sleepers

These Plate sleepers are rectangular in shape. The plates are parallel to the rails. The plates are fix in position with the tie bars. These connections are being similar to that of pot sleepers. The pot and plate sleepers are us with flat footed and Bull headed rails.

Box Sleepers

Box Sleepers are in box shapes. The box sleepers are not using nowadays in the modern construction of railway rail tracks.

C.S.T-9 sleepers

It has a triangular inverted pot on either side of the rail seat. And having a plate with a projecting rib and a box on the top of the plate. The connections are by means of rods of various types. These sleepers are easily assemble and dismantle without using mechanical equipment.

Rail Free Duplex sleepers

A joint sleeper of cast iron known as rail Free Duplex sleepers has been use as a rail joints in conjunction with it. These sleepers use to prevent the cantilever action between the two supports of the sleeper joints

2. Steel Sleepers

Most of the tracks lays with the metal sleepers. The following types of Steel Sleepers are as follows,

Key Type
Clip-Bolt Type
Spring Type

Key Type

Keys are use to hold the rail in sleepers. These keys are fix on both sides of sleepers to hold it tight. These keys are fix on opposite directions to each other.

clip-Bolt Type

This sleeper employs a bolt and clip for holding the rail. The four clip and bolt use for holding the rails. By using different types of the clips the sleepers use for any section of rail. The size of clip depends upon the weight of rails.

Spring Type

The rail seat is strengthened by a spring plate having two holes in sleepers on either sides.

civil techniques

Metal Sleepers

abbu riyaz 1 May, 2023

Metal sleepers use widely in the modern construction of railway tracks. The Metal sleepers are of cast iron and steel. In these various types of Metal sleepers, the sleeper which is economic uses in the construction of railway tracks.

Cast iron is widely engaging than steel because of its less tendency to corrosion. Metal sleepers use widely because of the shortage of wooden sleepers and its long life properties.

Types of Metal Sleepers

There are many Types of Metal Sleepers using in the construction of railway rail tracks. The following types are as follows,

Cast iron Sleepers and

Steel Sleepers

Cast iron Sleepers

The Cast iron sleepers are using widely in the construction of railway rail tracks. Cast iron are of many types as follows,

Bowl or Pot sleepers
Plate sleepers
Box sleepers
C.S.T-9 sleepers
Rail Free Duplex sleepers.

The main reason to use metal sleepers replacing wooden sleepers are because of growing scarcity of wooden sleepers.

Steel Sleepers

The following types of Steel Sleepers are as follows,

Key Type
Clip-Bolt Type
Spring Type

Requirements of Metal sleepers

Metal Sleeper should bears the compression and tensile stress acting on it.
It should be of low manufacturing cost and low maintenance.
It should provide proper grip on the rail track
And provide ballast to prevent dislocation of track due to vibrations and shocks cause by heavy loads.
Sleepers must be economical.
t should be easier to handle during the maintenance operations like lifting, packing, removal, and replacement.
The weight of sleepers should not be too heavy or too light.
It should have a moderate weight for ease of access.
And capable to resist shocks of rails because of a fast-moving load with vibration.
It should have a proper spacing between two sleepers for ease of maintenance for removal and replacement.
Sleeper to design in a way that they should not push out easily due to moving loads.
A sleeper to provide with anti-theft qualities.