CIV 1252H Infrastructural Renewal
Term Project#2 – Repair Proposal
th
Submission Date: Nov 17 ,2022
Performance Requirement of Repair Materials
The repair aims to extend the service life of these two parking structures to the next 15 years without
any facility shutdown caused by emergency repair. The objective of the repair project is expected to be
delivered under the pre-approved budget and allowable timeframe. The performance requirements of
the repair concrete structure include achieving desired strength, durability, and serviceability from
several physical properties shown below.
Corrosion- Compressive Strength ASTM C579
related Chemical Resistance(pH Value)
Problems Bond Strength
and damage Modulus of Elasticity ASTM C580
on the Ramp Shrinkage/Creep
Abrasion Abrasion Resistance
Loss in the Permeability
ground-floor Chemical Resistance(pH Value)
and second- Colour and Appearance
floor slab
Impact Compressive Strength ASTM C579
Damage on Bond Strength
four Coefficient of Thermal Expansion
Structural Adhesion to Concrete ASTM D4541
Columns Dimensional Stability
Scaling and Compressive Strength
Cracking on Resistance to Freezing and Thawing
Roof Slab Bond Strength
Scaling Resistance
Chemical Resistance(pH Value)
Repair Materials and Methodologies for Repair
Concrete Impacting by chipping hammer will be used for the damaged column on
Removal and structure#1 and the roof slab cleaning on structure#2 since the
Cleaning defective area is relatively small and close to each other. The condition
Impact survey identifies no reinforcement corrosion and carbonation problems
Hammer in these two spots, so abrasive blasting is not required for the cleaning
Versus process.
Abrasion Due to the relatively large repair area, abrasive blasting will be used for
Blasting the concrete ramp on structure#1. Most importantly, abrasive blasting
Versus can effectively remove all existing rust residue on steel reinforcement.
Concrete Mill Impacting with a chipping hammer will probably be required to remove
the contaminated concrete around exposed reinforcing steel to provide
a mechanical bond between the steel and repair material.
, Concrete mill will be used for the floor slab on the first and second-floor
slab because it can fix irregularities in the concrete and smooth the
surface in the least amount of time. The owner focuses on minimizing
the profits losses caused by the repair shutdown, and they would like to
apply for a light-colored surface coating for the interior concrete
surfaces for aesthetic improvement.
Damaged Method Comparison: Form and Pour versus Form and Pump
Concrete and Concrete Selection: Silica Fume Concrete Versus Fibre-reinforced Concrete
Reinforcement Conclusion
Repair Form and pour concrete is the only feasible option for ramp repair due to
the relatively small quantity requirement, providing the best dollar value
and workability. Once the substrate preparation is ready, the new material
will be placed in a bonded overlay, and the new cementitious repair material
must be compatible with the existing concrete substrate. Form and pump
are widely adapted for overhead and vertical application, which does not
work best for the horizontal slab. The quantity of fresh concrete is relatively
small, so the equipment cost is not ideal for small repair tasks.
Although silica fume concrete offers better robust chloride resistance and
compressive strength, fiber-reinforced concrete provides more tensile
strength against shrinkage and fatigue strength. The dimensional stability
and modulus of elasticity is the crucial attribute for the concrete ramp
repair, so fiber-reinforced concrete will be selected.
Additional steel reinforcement will be installed for corrosion rehabilitation
on the ramp. First, clean or remove corrosion and rust on the steel with
sandblasting and additional chipping by hand if required. Secondly, replace
damaged reinforcing steel with new coated bars and securely tie new
reinforcing steel into place if necessary. The coating selection of the installed
bar should comply with the existing reinforcement. Thirdly, set up the
formwork in the repair area for receiving new concrete, the corrosion-
inhibiting admixture should be added to the new concrete mix such as
chromates, nitrates, etc.
Scaling and Method Comparison: Urethane Injection with Shorecrete versus Form and
Cracking on Pump
Roof Slab Concrete Selection: Rapid Setting Concrete versus Silica Fume Concrete
Conclusion
Although the urethane injection is the most effective approach to fixing
water leakage problems caused by concrete cracking, it would not be
eligible for roof slab repair because the cracking is 5 meters long and close
to the scaling areas. We must first remove the cracking and scaling areas on
the roof slab. Then the waterproofing system with an enhanced drainage
design will be installed beneath the newly added concrete overlay. The form
and pump for the full-depth slab will be selected for roof slab rehabilitation
because it can reduce labor intensity and construction duration.
Shotcrete is most economical on vertical and overhead surfaces because it is
tedious to set up the formwork. But it would not meet the structural
requirement of the full-thickness repair for the roof slab because the repair
Term Project#2 – Repair Proposal
th
Submission Date: Nov 17 ,2022
Performance Requirement of Repair Materials
The repair aims to extend the service life of these two parking structures to the next 15 years without
any facility shutdown caused by emergency repair. The objective of the repair project is expected to be
delivered under the pre-approved budget and allowable timeframe. The performance requirements of
the repair concrete structure include achieving desired strength, durability, and serviceability from
several physical properties shown below.
Corrosion- Compressive Strength ASTM C579
related Chemical Resistance(pH Value)
Problems Bond Strength
and damage Modulus of Elasticity ASTM C580
on the Ramp Shrinkage/Creep
Abrasion Abrasion Resistance
Loss in the Permeability
ground-floor Chemical Resistance(pH Value)
and second- Colour and Appearance
floor slab
Impact Compressive Strength ASTM C579
Damage on Bond Strength
four Coefficient of Thermal Expansion
Structural Adhesion to Concrete ASTM D4541
Columns Dimensional Stability
Scaling and Compressive Strength
Cracking on Resistance to Freezing and Thawing
Roof Slab Bond Strength
Scaling Resistance
Chemical Resistance(pH Value)
Repair Materials and Methodologies for Repair
Concrete Impacting by chipping hammer will be used for the damaged column on
Removal and structure#1 and the roof slab cleaning on structure#2 since the
Cleaning defective area is relatively small and close to each other. The condition
Impact survey identifies no reinforcement corrosion and carbonation problems
Hammer in these two spots, so abrasive blasting is not required for the cleaning
Versus process.
Abrasion Due to the relatively large repair area, abrasive blasting will be used for
Blasting the concrete ramp on structure#1. Most importantly, abrasive blasting
Versus can effectively remove all existing rust residue on steel reinforcement.
Concrete Mill Impacting with a chipping hammer will probably be required to remove
the contaminated concrete around exposed reinforcing steel to provide
a mechanical bond between the steel and repair material.
, Concrete mill will be used for the floor slab on the first and second-floor
slab because it can fix irregularities in the concrete and smooth the
surface in the least amount of time. The owner focuses on minimizing
the profits losses caused by the repair shutdown, and they would like to
apply for a light-colored surface coating for the interior concrete
surfaces for aesthetic improvement.
Damaged Method Comparison: Form and Pour versus Form and Pump
Concrete and Concrete Selection: Silica Fume Concrete Versus Fibre-reinforced Concrete
Reinforcement Conclusion
Repair Form and pour concrete is the only feasible option for ramp repair due to
the relatively small quantity requirement, providing the best dollar value
and workability. Once the substrate preparation is ready, the new material
will be placed in a bonded overlay, and the new cementitious repair material
must be compatible with the existing concrete substrate. Form and pump
are widely adapted for overhead and vertical application, which does not
work best for the horizontal slab. The quantity of fresh concrete is relatively
small, so the equipment cost is not ideal for small repair tasks.
Although silica fume concrete offers better robust chloride resistance and
compressive strength, fiber-reinforced concrete provides more tensile
strength against shrinkage and fatigue strength. The dimensional stability
and modulus of elasticity is the crucial attribute for the concrete ramp
repair, so fiber-reinforced concrete will be selected.
Additional steel reinforcement will be installed for corrosion rehabilitation
on the ramp. First, clean or remove corrosion and rust on the steel with
sandblasting and additional chipping by hand if required. Secondly, replace
damaged reinforcing steel with new coated bars and securely tie new
reinforcing steel into place if necessary. The coating selection of the installed
bar should comply with the existing reinforcement. Thirdly, set up the
formwork in the repair area for receiving new concrete, the corrosion-
inhibiting admixture should be added to the new concrete mix such as
chromates, nitrates, etc.
Scaling and Method Comparison: Urethane Injection with Shorecrete versus Form and
Cracking on Pump
Roof Slab Concrete Selection: Rapid Setting Concrete versus Silica Fume Concrete
Conclusion
Although the urethane injection is the most effective approach to fixing
water leakage problems caused by concrete cracking, it would not be
eligible for roof slab repair because the cracking is 5 meters long and close
to the scaling areas. We must first remove the cracking and scaling areas on
the roof slab. Then the waterproofing system with an enhanced drainage
design will be installed beneath the newly added concrete overlay. The form
and pump for the full-depth slab will be selected for roof slab rehabilitation
because it can reduce labor intensity and construction duration.
Shotcrete is most economical on vertical and overhead surfaces because it is
tedious to set up the formwork. But it would not meet the structural
requirement of the full-thickness repair for the roof slab because the repair
