ETCONp - Ethiopian Construction Work Professionals

👉 Method for Designing the Rate of Bitumen and Aggregate for a Double Bituminous Surface Treatment (DBST) Road

🏷The design of the rate of bitumen and aggregate for a Double Bituminous Surface Treatment (DBST) road is crucial to ensuring durability, skid resistance, and water resistance.

🚧The process involves selecting appropriate materials, determining application rates, and verifying through field trials. Below is a detailed step-by-step method:

1. Selection of Materials

1.1 Bitumen

Type: Commonly used bitumen types for DBST include penetration-grade bitumen (e.g., 80/100, 60/70) or cutback bitumen (MC-30, MC-70) or emulsified bitumen (RS-1, RS-2, CRS-1, CRS-2).

Properties:
Adequate viscosity for proper spraying.
Good adhesion to aggregates.
Resistance to oxidation and aging.

1.2 Aggregates

Type: Crushed rock, crushed gravel, or crushed slag.

Gradation: Typically 6-12 mm for the first layer and 4-8 mm for the second layer.

Properties:

Clean, dry, and free from dust or clay.
High angularity for better interlocking.
Hard and durable to withstand traffic loads.

2. Determining the Application Rates

2.1 Determination of Bitumen Application Rate

The bitumen application rate varies based on the type of road, traffic volume, and aggregate size. It is usually determined by empirical methods or laboratory tests.

Factors Affecting the Rate of Bitumen:

Traffic Volume: Higher traffic requires lower bitumen content to prevent flushing.

Aggregate Porosity: More porous aggregates need higher bitumen rates.

Weather Conditions: Higher temperatures require adjustments to prevent bleeding.

2.2 Determination of Aggregate Application Rate

The aggregate rate is determined based on the required thickness, aggregate size, and bitumen rate.

Factors Affecting the Aggregate Rate:

Traffic Load: Heavy traffic roads require well-graded, durable aggregates.

Aggregate Shape: Angular aggregates interlock better, requiring slight adjustments to application rates.

3. Field Verification (Trial Sections)

Before full-scale application, a trial section should be carried out to verify the design rates.

3.1 Equipment Used

Bitumen Distributor: Ensures uniform spraying of bitumen.

Chip Spreader: Distributes aggregate evenly.

Rollers: Typically, 6-8 ton pneumatic tire rollers for proper embedment.

3.2 Application Process

1. Surface Preparation: Clean the surface from dust and debris.

2. First Bitumen Spray: Apply bitumen at the determined rate.

3. First Aggregate Layer: Spread the first layer of aggregates.

4. Rolling: Compact the first layer using rollers.

5. Second Bitumen Spray: Apply the second bitumen layer.

6. Second Aggregate Layer: Spread the second aggregate layer.

7. Final Rolling: Compact the second layer for proper embedment.

3.3 Post-Construction Check

Loose Aggregate Removal: Excess aggregate should be broomed off.

Adhesion Check: Ensure aggregates are well bonded to bitumen.

Traffic Opening: Allow curing before opening for full traffic.

4. Conclusion

Proper design of bitumen and aggregate rates is crucial for the longevity of a DBST road. Field trials should be conducted to fine-tune the application rates based on site conditions. Adjustments may be required based on traffic conditions, climate, and aggregate properties.

@etconp

👉በጎረቤት መሬት ውስጥ ወሰን አልፎ ግንባታ ስለመፈጸም (የሕግ አግባብ)

🏷ከግንባታ ሥራ ጋር ተያይዞ በሀገራችን ፍርድ ቤቶች ከቀረቡ ሪፖርቶች መካከል ሰፊውን ቦታ የያዘው «ጎረቤት ወሰን አልፎ አጥር ማጠር፣ እጽዋት መትከል እና በመሬት ውስጥ ወይም በአየር ላይ ግንባታ መፈጸም» በሚሉ ጉዳዮች የቀረቡ አቤቱታዎች ናቸው።

⏺በመሆኑም አንድ ሰው የይዞታ ማረጋገጫ ከተሰጠበት የይዞታ ድንበር መስመሮች ውጪ በመሬት ውስጥም ይሁን ከመሬት በላይ (በአየር ላይ አንጠልጥሎ) ግንባታ መፈጸም አይችልም።

🚧ግንባታ ይቅርና ባለይዞታው ካልፈቀደ በቀር እና በህግ ትእዛዝ ካልተሰጠ በቀር ማንም ሰው በሌላ ይዞታ ላይ አልፎ መግባት (መራመድ፣ መቆም) አይችልም (ፍ/ብ ሕ/ቁ 1216)።

💫አንድ ጎረቤት በራሱ ይዞታ ላይ ዛፍ ቢተክልና ዛፉ እያደገ ሲሄድ የዛፉ ሥሮች በመሬት ውስጥ ወደሌላኛው ባለይዞታ መሬት ውስጥ ቢገቡ አልፈው የገቡትን የዛፉን ሥሮች የመቁረጥ ግዴታ አለበት፣ የዛፉ ቅርንጫፎችም በአየር ላይ በሰው ይዞታ ላይ ከገቡ ወይም ቅርንጫፎቹ ወደሌላ ጎረቤት ይዞታ ውስጥ ከተስፋፉ እነዚያን ቅርንጫፎች የመቁረጥ ግዴታ አለበት (ፍ/ብ ሕ/ቁ 1212)

⏺በመሆኑም በፍትሐብሔር ህግ ላይ በግልጽ እንደተቀመጠው አንድ ሰው በጎረቤቱ ይዞታ ላይ ግንባታ የፈጸመ ከሆነ (በመሬት ውስጥ መሰረት ግንባታ Foundation፣ በመሬት ላይ ወለል ወይም በአየር ላይ ተንጠልጣይ ውቅር Cantliver Structure ሊሆን ይችላል) ይዞታ የተጣሰበት አካል የባለቤትነት አቤቱታ በፍትሐ ብሔር /ሕ/ቁ 1206 መሰረት በማዘጋጀት ስልጣን ላለው ፍ/ቤት የማመልከት መብት አለው፡፡ አቤቱታው ይዞታው በሚገኝበት አካባቢ ባለ ፍርድ ቤት ቢሆን የተመረጠ ሲሆን በይዘት ደረጃ የይዞታው ባለቤትነት ማረጋገጫ ሰነድ የተያያዘበት፣ ግንባታ የፈጸመው አካል ምን ያህል ካሬሜትር አልፎ እንደገባ፣ እና ያለአግባብ የተፈጸመውን የግንባታ አይነት በመጥቀስ ማቅረብ ይኖርባቸዋል።

⏺የአቤቱታው ፍሬ ነገር (ፍላጎት ደግሞ) ግንባታ የፈጸመው አካል አልፎ የገነባውን የግንባታ አይነት በራሱ ወጪ አፍርሶ ይዞታውን ቀድሞ በነበረበት ይዘት እንዲያስረክብ ውሳኔ እንዲወሰን የሚጠይቅ መሆን አለበት።

@etconp

👉A retaining wall

🚧is a structure designed to hold back soil or other materials and prevent them from sliding or eroding. It is commonly used in landscaping, civil engineering, and construction to create level areas on sloped terrain, support roadways, or prevent landslides.

⏺Retaining walls must withstand the pressure exerted by the retained material, known as lateral earth pressure.

🏷Types of Retaining Walls

⏺1. Gravity Retaining Wall

- Relies on its own weight to resist the pressure from the soil.
- Typically made of heavy materials like concrete, stone, or masonry.
- Suitable for shorter walls (up to 3-4 meters).

⏺2. Cantilever Retaining Wall

- Made of reinforced concrete or steel.
- Consists of a base slab and a vertical stem.
- Uses a lever arm (cantilever) action to resist soil pressure.
- Common for medium-height walls (up to 6-8 meters).

⏺3. Counterfort Retaining Wall

- Similar to a cantilever wall but includes vertical supports (counterforts) at regular intervals.
- Counterforts reduce bending moments and shear forces.
- Used for taller walls (over 8 meters).

⏺4. Buttress Retaining Wall

- Similar to a counterfort wall, but the supports (buttresses) are on the front side of the wall.
- Used when space behind the wall is limited.

⏺5. Sheet Pile Retaining Wall

- Made of thin, interlocking steel, wood, or vinyl sheets driven into the ground.
- Used in soft soils and tight spaces, such as waterfronts or temporary excavations.
- Suitable for both temporary and permanent applications.

⏺6. Anchored Retaining Wall

- Uses cables or rods (anchors) driven into the soil or rock behind the wall.
- Anchors provide additional support, especially for tall or heavily loaded walls.
- Commonly used in challenging soil conditions.

⏺7. Gabion Retaining Wall

- Constructed from wire baskets filled with rocks or other materials.
- Flexible and permeable, making it suitable for erosion control and drainage.
- Often used in landscaping and riverbank stabilization.

⏺8. Crib Wall

- Made of interlocking boxes or frames (cribs) filled with soil or gravel.
- Often used in landscaping and for low-height retaining walls.

⏺9. Reinforced Soil Retaining Wall

- Combines soil with reinforcement materials like geogrids or strips.
- The reinforcement increases the soil's strength and stability.
- Commonly used in highway and railway projects.

⏺10. Mechanically Stabilized Earth (MSE) Wall

- A type of reinforced soil wall with layers of reinforcement (geogrids or strips) and facing panels.
- Highly durable and cost-effective for large-scale projects.

📜Each type of retaining wall has specific applications based on factors like height, soil type, load requirements, and cost. Proper design and construction are essential to ensure stability and longevity.

@etconp