CASE STUDY
CONCRETE PARKADE
RESTORATION
Structural restoration of a multi-level concrete parkade including post-tensioned slab assessment, concrete repair, waterproofing design, and drainage system upgrades.
CASE STUDY
CONCRETE PARKADERESTORATION
Structural restoration of a multi-level concrete parkade including post-tensioned slab assessment, concrete repair, waterproofing design, and drainage system upgrades.
PROJECT OVERVIEW
This project involved comprehensive structural restoration of a multi-level post-tensioned concrete parkade in Vancouver. The parkade, built in the late 1980s, was experiencing ongoing water infiltration through the top deck slab, leading to PT tendon corrosion, concrete delamination, and active leaks onto the occupied floors below.
Zagrosia Engineering performed a detailed PT tendon condition assessment using ground-penetrating radar and selective destructive investigation. A restoration design was developed addressing both structural repair of compromised PT elements and waterproofing system replacement to prevent future water ingress.
PROJECT DETAILS
- LocationVancouver, BC
- Building TypeMulti-Level Concrete Parkade
- ServicesStructural Restoration & PT Slab Assessment
- JurisdictionCity of Vancouver
- CodeNBCC 2020 / BCBC 2018 / ACI 224R
- ExpertiseP.Eng — British Columbia
THE CHALLENGE
Post-tensioned concrete structures present unique rehabilitation challenges — cutting into the slab without severing live tendons requires careful GPR mapping and manual tendon location before any saw-cutting or core drilling. Two tendons were identified as fractured and required emergency restressing or supplemental non-PT reinforcement.
The parkade remained operational throughout the restoration, with vehicles required to access multiple levels at all times. Work zones were rotated across the deck in phases to maintain accessibility while allowing full restoration of each zone before moving to the next.
ENGINEERING APPROACH
PT Tendon Assessment
Ground-penetrating radar scanning and selective destructive investigation to map all tendon locations, identify fractured tendons, and assess waterproofing membrane condition across the full deck area.
Structural Repair Design
Supplemental non-PT reinforcement designed to replace the load-carrying contribution of fractured tendons. Concrete patch repair specifications developed for all delaminated and spalled areas.
Waterproofing System Design
New hot-applied rubberized asphalt waterproofing membrane and traffic topping specified for the top deck level, with new drainage slope and drain location design to eliminate ponding.
SCOPE OF WORK
GPR Tendon Mapping
Full deck ground-penetrating radar scan to locate all PT tendons prior to any cutting or drilling
PT Condition Assessment
Selective destructive investigation to assess tendon corrosion levels and identify fractured elements
Structural Repair Specifications
Supplemental reinforcement and concrete patch repair design for all structurally deficient areas
Waterproofing System Design
New waterproofing membrane, drainage slope, and traffic topping specifications for the top deck
Construction Phase Services
Site observation, tendon location verification, and repair contractor guidance throughout construction
OUTCOME
WATERTIGHT & STRUCTURALLY SOUND
The parkade restoration eliminated the ongoing water infiltration and restored full structural capacity to all compromised PT slab zones. The new waterproofing system has performed without leaks since installation, and all fractured tendon zones have been remediated to code-compliant standards.
START YOUR PROJECT
DO YOU WANT TO START YOUR PROJECT?
Every project is unique. Contact us to discuss your specific requirements, and discover how we can help.
DO YOU WANT TO START YOUR PROJECT?
Every project is unique. Contact us to discuss your specific requirements, and discover how we can help.