This presentation aims at providing clear and down to earth definitions of what Post-Tensioning systems are, the different repair strategies related to these systems, and critical factors to be accounted for during the design and execution of any intervention on a Post-Tensioning slab.
In this presentation, we will address the effect that corrosion has on our concrete infrastructure, including buildings, bridges, sea walls, cooling towers, docks, and many other reinforced concrete structures.
This session describes how novel corrosion management techniques have been used to extend the life of a variety of heritage structures, including a church, a bridge and even a castle.
Dallas City Hall and Plaza are recognized by many due to the opening scenes of Dallas, the television show. What is less known is that the structure is a significant early example of bonded post-tensioned concrete which was utilized throughout the superstructure and two-story parking garage constructed beneath the plaza. Opened in 1977, the parking garage is a two-way bonded post-tensioned concrete slab with unreinforced drop panels supported by flared circular concrete columns. The garage covers two city blocks, extends under two adjacent multi-lane streets, and supports mature landscaping, pool, fountain, and up to 11’-0” of soil. In 2017, several square feet of a drop panel fell from the structure and subsequent observations found multiple locations of drop panel and column capital failures. A structural investigation including destructive and non-destructive testing, and analysis of the existing structure was undertaken to determine the cause of the failures.
A follow-on presentation to the discussion of our evaluation of over 1500 tire and lube facilities across the United States that prescribed immediate repairs where necessary, reinforcement where deterioration reduced capacity below acceptable levels and coatings necessary to protect structural steel and structural concrete (i.e. our 2019 Philadelphia presentation). This will be an in-depth presentation of how repairs were specified for (3) specific types of structures. The (3) structure types are exposed structural concrete, composite metal deck and fully reinforced form deck slabs all supported by steel structures and reinforced concrete walls. Presentation will include before, during and completion photos of each project discussed. Again, touch on the evaluation processes to include demand to capacity ratios review, evaluation system and inspection form, triggers to determine when shoring is necessary, calculation of capacities per AISC 360, ACI 318, ACI 562 and local building codes.
In new construction, cracks can appear for variety of reasons: curing, temperature deviation, pressure from adjacent conditions, or settlement. This presentation will outline various types of cracking, how to plan to avoid them, and how to address them after concrete has been placed.
This presentation is based on the updated revisions to the original document entitled Guide for the Selection of Grouts to Control Leakage in Concrete Structures. This webinar addresses the selection of chemical grouts typically used to control and/or mitigate the ingress of water in concrete structures, specifically cracks and joints.
Galvanized corrugated metal and concrete underground culverts are common infrastructure in North American highways and stormwater management. A shotcrete lining is a cost-effective and efficient method to strengthen and significantly extend their useful life.