👉1.1 Classification of Construction Materials Construction materials can be classified into:

I) Metallic and Non-metallic
a. Non-metallic
- Cementing materials
- Concrete
- Timber
- Stone
- Plastics
- Ceramics

b. Metallic
- Ferrous
• Wrought iron
• Cast iron
• Steel
- Non Ferrous
• Aluminium
• Copper
• Lead
• Zinc

II) Based on their physical Nature:
a) Solidof
b) Liquid
c) Gaseous

III) Based on their mode of manufacture
a) Naturally occurring materials
b) Industrially produced materials
c) Materials produced at construction site

1.2 Properties of Materials
a) Physical properties
• Density and specific gravity
•Mechanical properties
• Thermal properties
• Acoustical properties
b) Chemical properties

Corrosion Here only thegreat mechanical properties are dealt with since they have a great practical significance in Civil Engineering.

1.2.1 Mechanical Properties When forces are applied to a solid body, two results are produced:

1) Internal resisting forces
2) Deformation .
The internal forces and deformations are called stresses and strains respectively.

Depending up on the arrangement and direction of the external forces, the stress produced may be:
a) Tensile stress
b) Compressive stress
c) Shearing stress
d) Bending stress
e) Torsional stress
f) Combinations of the above stresses

Deformation:
a) Elastic if it recovers when the external force is released
b) Plastic if it fails to recover when the external force is released If a material is capable to carry its own weight and any applied load, it is assumed to be strong material.
This way is that the strength of the material is determined. When a material is said to be strong it is its strength in tension or compression that is usually referred to, but it is often necessary to know its strength in shear and torsion as well.

1.3 Tests for Mechanical Properties Selection of material for a particular structural application depends on its mechanical properties.
There are standard mechanical tests to measure these properties. Mechanical tests are used to examine the performance of materials under the action of external force.

1.3.1 Classification of Mechanical Tests
I) II) With reference to the direction of the external
forces
a) Tension test
b) Compression test
c) Shear test
d) Bending test
e) Torsion test

With reference to the rate and duration of the load application
a) Static Tests: these are made with gradually increasing load, such as ordinary tests in tension, compression etc.
b) Dynamic test: these are made with suddenly
applied loads, as by falling weight
c) Wear tests: these are made to determine resistance to abrasion and impact, as in the case of paving materials
d) Longtime tests: there are made with loads applied to the object under test for a long period of time. They are used for materials such as concrete.
e) Fatigue test: these are made with fluctuating stresses repeated a large number of times

III) With reference to the effect of the test on the specimen
a) Destructive tests: Under these test methods, the specimens are either crushed or ruptured and made useless at the end of the tests
b) Non-destructive tests: These are usually used to test the strength of members of existing structures without affecting their performance.

@etconp

ማሳሰቢያ/ Announcement 📢

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የሽልማት ጥያቄው አሸናፊውን የምንለየው November 20- 2023 ሲሆን ሽልማቱ 500 ብር ነው።

ጥያቄው የተለቀቀው በፌስቡክ ገፃችን እና በ ኢኒስታግራም ገፃችን ነው።

አሸናፊው የሚለየው ለመልሶቹ ብዙ ላይክ ያገኘ ነው። በትንሹ 30 ላይክ ሊኖረው ይገባል

ውድድሩን በፌስቡክ እየመራ ያለው በፌስቡክ ስሙ Fiseha Birhan ሲሆን 52 ላይክ አግኝቷል።

በ ኢንስታግራም ደግሞ እየመራች ያለችሁ በ ኢንስታግራም username @fif_raya ስትሆን 41 ላይክ አግኝታለች

አሁንም አልረፈደም

ጓደኞቻችሁን የለጠፋችሁትን ፎቶ ላይክ አስደርጉ

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👉What is the difference between working stress approach and limit state approach?
 
🌟For working stress approach, service loads are used in the whole design and the strength of material is not utilized in the full extent.

⏺In this method of design, stresses acting on structural members are calculated based on elastic method and they are designed not to exceed certain allowable values. In fact, the whole structure during the lifespan may only experience loading stresses far below the ultimate state and that is the reason why this method is called working stress approach. Under such scenario, the most economical design can hardly be obtained by using working stress approach which is now commonly used in the design of temporary works.
 
⏺For limit state approach, for each material and load, a partial safety factor is assigned individually depending on the material properties and load properties. Therefore, each element of load and material properties is accurately assessed resulting in a more refined and accurate analysis of the structure.

⏺In this connection, the material strength can be utilized to its maximum value during its lifespan and loads can be assessed with reasonable probability of occurrence.

⏺Limit state approach is commonly used for the majority of reinforced concrete design because it ensures the utilization of material strength with the lowest construction cost input.

https://t.me/ETCONpWORK

👉በህንድ እየተገነባ ያለ ዋሻ የተደረመሰባቸውን 40 ሰዎች ነፍስ ለማዳን ትንቅንቅ እየተደረገ ነው

🌟የነፍስ አድን ሰራተኞች ፍርስራሹን በማስወገድ መውጫ አጥተው ያሉትን ሰራተኞችን በህይወት ለማትረፍ ለሁለት ቀናት ያለእረፍት እየሰሩ ናቸው
በህንድ እየተገነባ ያለ ዋሻ የተደረመሰባቸውን 40 ሰዎች ነፍስ ለማዳን ትንቅንቅ እየተደረገ ነው ተባለ። 

🌟በህንድ ኡታራካንድ ግዛት የሚገኝ የመሬት ውስጥ  የመንገድ ዋሻ የተደረመሰባቸውን 40 የግንባታ ሰራተኞች በህይወት ለማትረፍ ከፍተኛ ጥረት እየተደረገ  ይገኛል።

🚧ይህ 3 ማይል የሚረዝመው ዋሻ የመደርመስ አደጋ ያጋጠመው ባለፈው እሁድ መሆኑን ስካይ ኒውስ ዘግቧል።

🚧የነፍስ አድን ሰራተኞች ፍርስራሹን በማስወገድ መውጫ አጥተው ያሉትን ሰራተኞችን በህይወት ለማትረፍ ለሁለት ቀናት ያለእረፍት እየሰሩ ናቸው።

🌟ሰራተኞቹን በህይወት ለማውጣት ፍርስራሹን በጥንቃቄ እያወጡ መሆናቸውን ባለስልጣናቱ ተናግረዋል።

🌟እየተንጠባጠበ ያለው ፍርስራሽ እንቅፋት እንደሆነባቸው የገለጹት ባለስልጣናቱ ማክሰኞ ሌሊት ወይም ሮብዕ ሰራተኞቹን በህይወት ማውጣት ይቻላል የሚል ግምታቸውን አስቀምጠዋል።

🌟የዲሳስተር ማኔጅመንት ባለስሌጣን የሆኑት ዴቨንድራ ሲኝ ፖትዎል "መውጣት ላልቻሉት ሰራተኞች እና የስራ ኃላፊዎች ምግብ፣ ውሃ እና ኦክስጅን እያቀረብንላቸው ነው" ብለዋል።

🌟ከመንግስት እና ከትምህርት ተቋማት የተውጣጣ የዲኦሎጂስቶች ቡድን አደጋው የተከሰተበትን ምክንያት ለማወቅ ቦታው ላይ ደርሷል።

🌟በዋሻው ውስጥ ከ50-60 የሚሆኑ ሰራተኞች የነበሩ ቢሆንም 10-20 የሚሆኑት የስራ ፈረቃቸው በማለቁ አደጋው ሳይከሰት ወጥተዋል ተብሏል።

🚧የመንገድ ግንባታው በግዛቱ ያሉ የሂንዱ ቴምፕሎችን ለማገናኘት ያለመ የመንግስት ፕሮጀክት አካል መሆኑ ተገልጿል።

Via Alain

@etconp

👉Hardened Concrete Properties

1. Strength:

The strength of concrete is basically referred to compressive strength and it depends upon three factors.
1- Paste Strength 
2- Interfacial Bonding 
3- Aggregate Strength
1. Paste strength:
It is mainly due to the binding properties of cement that the ingredients are compacted together. If the paste has higher binding strength, higher will be strength of concrete.
2. Interfacial bonding:
Interfacial bonding is very necessary regarding the strength. Clay hampers the bonding between paste and aggregate. The aggregate should be washed for a better bonding between paste and aggregate.
3. Aggregate strength:
It is mainly the aggregate that provide strength to concrete especially coarse aggregates which act just like bones in the body. Rough and angular aggregate provides better bonding and high strength.
Factors affecting Strength of concrete:
Following are the factors that affect the strength of concrete:
1. Water-Cement ratio 
2. Type of cementing material 
3. Amount of cementing material 
4. Type of aggregate 
5. Air content
6. Admixtures
1. Water-Cement ratio:
It is water cement ratio that basically governs the property of strength. Lesser the water cement ratio, greater will be strength.
2. Type of cement:
Type of cement affect the hydration process and therefore strength of concrete.
Amount of cementing material: it is the paste that holds or binds all the ingredients. Thus greater amount of cementing material greater will be strength.
3. Type of Aggregate:
Rough and angular aggregates is preferable as they provide greater bonding.
4. Admixtures:
Chemical admixtures like plasticizers reduce the water cement ratio and increase the strength of concrete at same water cement ratio. Mineral admixtures affect the strength at later stage and increase the strength by increasing the amount of cementing material.

@etconp

ገደል ላይ የተሰራ ቤት/ Building a house in a cliff

ማሳሰቢያ/ Announcement 📢

5 days left / 5 ቀን ቀረው አሁንም አልረፈደም ተወዳደሩ



የሽልማት ጥያቄው አሸናፊውን የምንለየው November 20- 2023 ሲሆን ሽልማቱ 500 ብር ነው።

ጥያቄው የተለቀቀው በፌስቡክ ገፃችን እና በ ኢኒስታግራም ገፃችን ነው።

አሸናፊው የሚለየው ለመልሶቹ ብዙ ላይክ ያገኘ ነው። በትንሹ 30 ላይክ ሊኖረው ይገባል

ውድድሩን በፌስቡክ እየመራ ያለው በፌስቡክ ስሙ Fiseha Birhan ሲሆን 52 ላይክ አግኝቷል።

በ ኢንስታግራም ደግሞ እየመራች ያለችሁ በ ኢንስታግራም username @fif_raya ስትሆን 41 ላይክ አግኝታለች

አሁንም አልረፈደም

ጓደኞቻችሁን የለጠፋችሁትን ፎቶ ላይክ አስደርጉ

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Office:- Bulgariya street awebane trading S.C Bulding 1st floor

Website:- www.elegas.com.tr

Email:- ethiopia@elegas.com.tr

👉ኣዲሱ ቻናላችን ተቀላቅለዋል?

⚡️ዛሬ የወጡ ጨረታዎች ጨምሮ

🌟አዳዲስ የ ኮንስትራክሽን ስራ እና ጨረታ ሲወጡ በቀላሉ ለመመልከት ከታች ባለው ሊንካችን ይቀላቀሉን።

📌እንዲሁም ለወዳጆቻቹ SHARE በማረግ አዳርሱ።

https://t.me/ETCONpWORK

👉Types of Joints in Construction

▶️Construction Joints
▶️Expansion Joints
▶️Contraction Joints

🌟Construction Joints

*At first, we cannot pour a larger quantity of concrete in a
single time. So at that time, a certain portion has poured as
per the recommended shuttering design and the remaining portion will be poured after a certain period.

In that, the construction joints are using to connect the old
and fresh concrete and it is also called as cold joints.

🌟Expansion Joints

*As we discussed, the construction materials are formed by the different raw material.

The concrete may shrink or
expand due to the weather condition.

*So the expansion joints gap are provided to accommodate
the movement happening by the expansion or shrinkages
and it is avoiding the disfiguration of the structure.

*Mostly the expansion joint gaps are providing in large
structure & bridge girder to spread eventual stress. The joint gaps are filled by the expansion material like fibre, bitumen or some other special material.
*Expansion joint might be provided in mid of each
span in bridges.
*The provision of expansion joints is when the
structure length exceeding 45m.
*The reinforcements should not be provided on the
expansion joint area.
*The expansion joint material will be different based on
the structure.
*The expansion joints are provided as per IS 3414.

🌟Contraction Joints

*It is another type of joints which controls the cracks
happening due to shrinkages. The contraction joints are
placed as a groove where the crack may form in concrete.
If the shrinkage crack is formed in the concrete slab then
the contraction joints prevent spreading on the other area.
*Specification The width of the groove should not be less than 5mm.
*The contraction joint depth is 1/4th of the Concrete mean depth.
*It should be placed in the weakest zone of the slab.
Another name of contraction joint is Control Joint .

http://t.me/COTMp

Is it structural problem or just plastering cracking down ?


ማሳሰቢያ/ Announcement 📢

4 days left / 4 ቀን ቀረው አሁንም አልረፈደም ተወዳደሩ



የሽልማት ጥያቄው አሸናፊውን የምንለየው November 20- 2023 ሲሆን ሽልማቱ 500 ብር ነው።

ጥያቄው የተለቀቀው በፌስቡክ ገፃችን እና በ ኢኒስታግራም ገፃችን ነው።

አሸናፊው የሚለየው ለመልሶቹ ብዙ ላይክ ያገኘ ነው። በትንሹ 30 ላይክ ሊኖረው ይገባል

ውድድሩን በፌስቡክ እየመራ ያለው በፌስቡክ ስሙ Fiseha Birhan ሲሆን 57 ላይክ አግኝቷል።

በ ኢንስታግራም ደግሞ እየመራች ያለችሁ በ ኢንስታግራም username @fif_raya ስትሆን 48 ላይክ አግኝታለች

አሁንም አልረፈደም

ጓደኞቻችሁን የለጠፋችሁትን ፎቶ ላይክ አስደርጉ

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SPONSOR

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Elevator and Escalator

📞 +251 971 71 71 71
📞 +251 994 69 69 69

Office:- Bulgariya street awebane trading S.C Bulding 1st floor

Website:- www.elegas.com.tr

Email:- ethiopia@elegas.com.tr

👉Picture Of The Day

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