Civil Work in Plants & Refineries

This article is about Civil Concrete Paving Work  and focusing to the engineers, technicians and supervisors. You will find lot of documents related to this article. Just navigate our website  www.paktechpoint.com  and find more articles. Please! Do not forget to subscribe our You tube channel also. Thanks in Advance.

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Civil Concrete Paving Work

Standard paving procedure start from the lower side of the carriageway towards the high side. All pavement layers shall have executed in full compliance with Standard & Specifications for Roadworks.
The pavement layer will be constantly checked ensuring that the pavement layer depth is achieved and maintained. The pavement layers will be laid in accordance with the specification and any cold joints made during the progress of the works will be cut back creating a vertical face and treated in accordance with the specification. The finished level will then be checked and passed off prior to the next layer being laid.

Procedure Civil Concrete Paving Work

1. Concrete Paving shall be in accordance with SAES-S-020 ” (ARAMCO Document in this article)Industrial Drainage and Sewers” and as follow:
a.) Areas subject to spills, wash water, firewater and sidewalk shall be paved with a minimum thickness of 100 mm of reinforced concrete with a minimum reinforcement of 150×150 MW9 x MW9 welded wire fabric. Areas subject to vehicular traffic shall be in accordance with SAES-Q-001 para 4.18b( Aramco standard.

b.) Paving slabs subject to vehicular traffic shall be a minimum thickness of 150 mm of reinforced concrete. The design load shall be as specified in paragraph 4.14 of this standard. The design of the paving shall be based on ACI 360R. Minimum reinforcement shall be 150×150 MW18.7 x MW18.7 welded wire fabric or equivalent.
c.) Paving slope to the catch basins or trenches shall not be less than 1:65 (1.5%). The maximum drop to catch basins from high point of paving shall be 200 mm. (refer to drawing VB-555303.) d.) Where foundations protrude through the paving, 12 mm diameter reinforcing bars, 800 mm long, shall be placed diagonally in the paving at all interior corners.
e.) Concrete paving shall have control or construction joints located at a maximum spacing of 6
meters on centers in both directions.
f.) Expansion joints shall be used in paving adjacent to all poured in place concrete members.
g.) Top of concrete shall be broom finish in one direction perpendicular to traffic.

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This article is about Concrete Paving Hairline Crack Repair  and focusing to the engineers, technicians and supervisors. You will find lot of documents related to this article. Just navigate our website  www.paktechpoint.com  and find more articles. Please! Do not forget to subscribe our You tube channel also. Thanks in Advance.

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Concrete Paving Hairline Crack Repair

1) Defects on concrete paving can be due to the use of excessive water, poor cement, poor construction practices, improper mixture proportioning, dirty or low quality aggregate and inadequate curing.
2) A deficiency must be differentiated from the actual cause and it is imperative that causes and not symptoms are dealt with wherever possible or practical. For example, cracking is a symptom of distress that may have a variety of causes.

3) Hollow spaces and cavities left in concrete mass on surface or inside the concrete mass where concrete could not reach. These look like honey bees nest, honeycombs which are on sides are visible to naked eyes and can be detected easily as soon shuttering is removed.

4) Due to non-reaching of concrete to all places in which cavities and hollow to hollow pockets are created. Main reasons are improper vibration during concrete, less cover to
reinforcement bars and use of very stiff concrete (this can be avoided by controlling water as per slump test).
5) Selection of the correct repair technique for cracking depends on knowing whether the
cracking is due to repeated thermal cycling, accidental overloading, drying shrinkage,
inadequate design or construction, or some other cause. Only after the cause or causes are known can rational decisions be made concerning the selection of a proper repair system.

Preparation & Repair Methods

a. As per manufactures recommendation approved repair materials shall be applied by skilled mason assuring that this material pushed to fill all surface voids.
b. All identified surfaces to be repaired shall be chipped out with V-grove shape carefully and clean the surface surroundings to expose dense and sound concrete and ensure no feathered edges at the area perimeter of the chipped surface any exposed steel
reinforcement shall be thoroughly cleaned and treated as required according to the manufacturer recommendations as per the selected material to be used for the repair.
c. Chipping with a V-Grove cut to the depth of the developed cracks to enlarge and
clean the area by blowing out with oil free compressed air washes the chipped and allows drying.
d. Brushes apply of suitable repair material on the exposed steel reinforcement rods and chipped surface. Mix components of the approved repair materials shall be applied according to the manufacturers’ instructions.

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This article is about PROCEDURE FOR ASPHALT CONCRETE PAVING AND ROAD ACTIVITIES  and focusing to the engineers, technicians and supervisors. You will find lot of documents related to this article. Just navigate our website  www.paktechpoint.com  and find more articles. Please! Do not forget to subscribe our You tube channel also. Thanks in Advance.

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PROCEDURE FOR ASPHALT CONCRETE PAVING AND ROAD ACTIVITIES

This Procedure describes the steps to be taken and sequence of events necessary to enable satisfactory completion of each activity.

Code & Standards Used for ASPHALT CONCRETE PAVING AND ROAD ACTIVITIES

SAES-Q-006 :    Asphalt and Sulfur Extended Asphalt Concrete Paving

SAES-A-114 :   Excavation and backfill

SABP-Q-010:  Mix design and Construction of Sulfur Extended Asphalt Concrete

AASHTO : AASHTO guide for Design of Pavement Structures. American Association of State highway and Transportation Officials, 1993.

AASHTO M 17: Standard Specification for mineral Filler for Bituminous Paving Mix

AASHTO M 156: Standard Specification for Requirements for Mixing Plants for Hot­Mixed, Hot-laid Bituminous Paving Mixture.
AASHTO T 49: Standard Method of Test for Penetration of Bituminous Materials.

AASHTO T 51: Standard method of Test for Ductility of Bituminous Materials.

AASHTO T 53 : Standard Method of Test for Softening Point of Asphalt (Bitumen) and Tar in Ethylene Glycol (Ring and Ball).
AASHTO T 180 : Moisture Density Relation of Soils using a 10-lb (4.54kg) Rammer And an 18 inch (457 mm) drop.
AASHTO T 193:  California Bearing Ratio

ASTM C88 :   Test Method for Soundness of Aggregates by use of Sodium Sulfate or Magnesium Sulfate.
ASTM C117 : Test Method for Materials Finer than 0.075mm (no.200) sieve in  Mineral Aggregates by Washing.
ASTM C131  :Test Method for Resistance to Degradation of Small-size Coarse Aggregate by Abrasion and Impact in the Los Angeles Machine.

ASTM C136 : Test Method for Sieve Analysis of Fine and Coarse Aggregates.
ASTM C142 : Test Method for Clay Lumps and Friable Particles in Aggregates.
ASTM C535  :Test method for resistance to Degradation of Small-large Coarse  Aggregate by Abrasion and Impact in Los Angeles machine.
ASTM D75: Particles for Sampling Aggregates.
ASTM D4791: Test method for Flat particles or Elongated Particles or Flat and Elongated particles in Coarse Aggregates.
ASTM D5 : Standard Test method for Penetration of Bituminous Materials.
ASTM D36: Standard Test for Method of Softening Point of Bituminous Materials.
ASTM D113: Standard Test Method for Ductility of Bituminous Materials.
ASTM D1559: Test Method for Resistance to Plastic Flow of Bituminous Mixtures using Marshall Apparatus.
ASTM D2041 : Test Method for Theoretical Maximum Specific Gravity and Density of  Bituminous Paving Mixtures.
ASTM D2172 : Test Method for Quantitative Extraction of Bitumen from Bituminous Paving Mixture.
ASTM D2726  : Test Method for Bulk Specific Gravity and Density of Non-Absorptive Compacted Bituminous Mixtures.
ASTM D2726 : Standard Test Method for Viscosity Determination of Asphalt at Elevated temperature using Rotating Viscometer.
ASTM PS 90-97 : Provisional Test Method for Asphalt Content of Hot-mix Asphalt by  the Ignition Method.
ASTM C5  :Standard Specification for Quicklime for Structural Purposes.
ASTM C150:  Standard Specification for Portland Cement.
ASTM D1156 : Test Method for Density and Unit Weight of Soil in place by the Sand-cone Method.
ASTM D1157 : Test Method for Laboratory Compaction Characteristics of Soil Using Modified effort (56,000 ft-lbs/ft3 -2,700 km/m3).
ASTM D2419: Test Method for CBR of Laboratory Compacted Soil.
ASTM D2922: Test Method for Density of Soil and Soil aggregate in Place by  Nuclear Methods (Shallow Depth).
ASTM D4253 : Test Method for Maximum Index Density and Unit Weight of Soils using a Vibratory Table.
ASTM D4254 : Test Method for Minimum Index Density and Unit Weight of Soils
TASTM D4318 : Test Method for Liquid Limit, Plastic Limit and Plasticity index of soils. and Calculation of Relative density.
ANSI/ASSE A10.12: Safety Requirements for Excavation
GI 1021.000 : Street and Road Closure, Excavation Reinstatement and Traffic

Preparation of sub grade

• Perform subgrade preparation. Fill all depressions, level the surface, remove all unsuitable materials and replace with materials approved by Saudi Aramco.
• Compact the subgrade according to the requirements in SAES-A-114 Section 6.3.1.1 and 6.3.2.5 (ARAMCO STANDARD)
• Following compaction, check for air holes, ruts, soft spots and other unsuitable subgrade conditions. Confirm compliance to Saudi Aramco Standard requirements.
• Where rolling is required, any areas inaccessible to a roller will be compacted by either mechanical or hand tamper until the Saudi Aramco requirements had been attained.
• Before placing base course layer, check conformance to alignment, grade, slopes and cross- sections shown on IFC drawings and as required by the Project Specifications.

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This article is about Procedure for Concrete Repair  and focusing to the engineers, technicians and supervisors. You will find lot of documents related to this article. Just navigate our website  www.paktechpoint.com  and find more articles. Please! Do not forget to subscribe our You tube channel also. Thanks in Advance.

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Procedure for Concrete Repair

This Procedure describes the step by step procedure for all affected concrete structures noticed (after the removal of form works).

General Procedure for Concrete Repair

1) Defects on structural concrete can be due to the use of excessive water, poor cement, poor construction practices, improper mixture proportioning, dirty or low quality aggregate and inadequate curing.
2) A deficiency must be differentiated from the actual cause and it is imperative that causes and not symptoms are dealt with wherever possible or practical. For example, cracking is a symptom of distress that may have a variety of causes.
3) Hollow spaces and cavities left in concrete mass on surface or inside the concrete mass where concrete could not reach. These look like honey bees nest, honeycombs which are on sides are visible to naked eyes and can be detected easily as soon shuttering is removed.

4) Due to non-reaching of concrete to all places in which cavities and hallow to hallow pockets are created. Main reasons are improper vibration during concrete, less cover to reinforcement bars and use of very stiff concrete (this can be avoided by controlling water as per slump test).
5) Selection of the correct repair technique for cracking depends on knowing whether the cracking is due to repeated thermal cycling, accidental overloading, drying shrinkage, inadequate design or construction, or some other cause. Only after the cause or causes are known can rational decisions be made concerning the selection of a proper repair system.

Work Procedure

1) Preparation & Repair Methods

a. As per manufactures recommendation approved repair materials shall be applied by skilled mason assuring that this material pushed to fill all surface voids.
b. All identified surfaces to be repaired shall be chipped out carefully and clean the surface surroundings to expose dense and sound concrete and ensure no feathered edges at the area perimeter of the chipped surface any exposed steel reinforcement shall be thoroughly cleaned and treated as required according to the manufacturer recommendations as per the selected material to be used for the repair.
c. Chipping along the cracks to enlarge and clean the enlarged cracks blowing out by oil free compressed air washes the chipped and allows drying.
d. Brushes apply of suitable repair material on the exposed steel reinforcement
rods and chipped surface. Mix components of the approved repair materials shall be applied according to the manufacturers’ instructions.

2) Concrete Defects

a. Shrinkage Cracks – Repair of concrete after the plastic shrinkage cracks have formed usually consists of sealing them against ingress of water by brushing in cement or low viscosity polymers.
b. Settlement Crack – Remedial measures after the concrete has hardened consist of sealing the cracks in order to protect the reinforcement. However, consolidation of concrete immediately after the cracks start to form is by far the best course of action.
c. Dormant or Dead Cracks – Cracks wider than about 1.0 mm on the horizontal surfaces can usually be sealed by filling them with cement grout. This is commonly done by brushing in dry cement followed, if necessary, by light spraying with water.
d. Live Cracks – The sealant must then be adhered to the sides of the chase but debonded from the bottom so that the movement is spread over the full width of the chase.

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