230 Park Avenue (The Helmsley Building)
The Helmsley Building was built in 1929 and over the years has gained iconic status and is one of the most recognized skyscrapers in the city. The building is constructed of a transitional structural steel frame clad in a terra-cotta cladding (typical of the era 1890-1950), including 32 three-storey Corinthian columns. Many elements of the building were experiencing embedded steel corrosion, including the structural steel lattice columns within the colossal terra-cotta enclosures. The expansion of the steel caused by the corrosion was severely damaging the masonry cladding.
A low carbon ICCP system was designed to protect the historic structure alongside embeddable corrosion rate probes to monitor and control the system for the long-term. Corrosion rate data are collected by the AchillesICP network management system and uploaded to AiMS, where it is available securely online to the owner and their representatives, allowing remote control of performance and to make predictive maintenance decisions.
Product / System Used
LoCem® +point® ICCP system, with CP200 corrosion rate probes, AchillesICP online management network and AiMS.
Project Details
The target locations for ICCP were the steel sections with the colonnades at 29th to 32nd floors. The colonnades were subject to either full height or partial height repairs to the terracotta and full height installation of ICCP to protect the steel in the future.
LoCem® +point® is an ICCP anode mortar was applied within the bed joints and drilled in to provide 360° protection of the steel surfaces. +point® is installed using a conventional repointing gun and finishing tools operating behind the heritage mortar finish to pass protection current to the structural steelframe.
Project Impact
This historic fabric of the structure was protected through non-invasive repairs, helping to retain embodied carbon. Coupled up with the use of LoCem® +point®, an AACM geopolymer manufactured from industrial waste streams, meant low carbon protection and enhanced resilience for whole life of the protected elements of the property.
The use of AiMS means that valuable structural health data is provided and archived for the long-term, meaning higher cost savings, performance transparency and protection of asset value.
Awards
Lucy G Moses Preservation Award, April 2022 – Presented by the New York Landmarks Conservancy