PPC 1121 Polyester Polymer Concrete place on Orthotropic Steel Deck (OSD) Systems

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PPC 1121 Polyester Polymer Concrete placed on Orthotropic Steel Deck (OSD) systems Kwik Bond Polymers has developed a Polyester Polymer Concrete (PPC) system that is uniquely suited to perform as an overlay for Orthotropic Steel Deck bridges. The following are some examples of the system in research and implementation.

1. Poplar Street Bridge In 2012-2013 more than 6,500SF of PPC 1121 was installed on the Poplar Street Bridge OSD at thicknesses varying from 0.5” to 2.5” to match existing 0.5”-0.75” Methyl Methacrylate (MMA) and poly-urea polymer concretes by others and a variety of thicker asphalt mixes up to 2.5”. It has been confirmed by MoDOT that all PPC 1121 installations remained fully adhered to the deck with no visible signs of cracking until the time that it was removed and replaced with Steel Fiber Reinforced Concrete (SFRC) under MoDOT contract #161021-F01 in 2018-2019. It was reported that PPC 1121 test patches were extremely difficult to remove from the Poplar Street OSD deck, more so than any other trial material involved.

The proven adhesion of PPC 1121 to OSD as demonstrated in the successful test patches on the Poplar Street Bridge led to PPC 1121 being the only polymer concrete to be included in final design consideration for the resurfacing project. MMA and poly-urea polymer concretes were not considered in the final design reportedly due to placement thickness limitations and poor performance on the bridge to date. After several failed test patch attempts over several years, failures in various MMA and poly-urea overlays

exhibiting excessive delaminations, cracking and spalling (likely caused by high temperature softening, inherent behaviors of these other low-modulus polymer concretes) led to elimination from consideration on this project. In addition, a desire for maximizing stiffness of the thin OSD steel plate section became the primary design criteria.

The full list of materials under consideration during the final design phase for the Poplar Street Bridge resurfacing project included 1) 2.5” PPC 1121 , 2) 2.5” Epoxy Asphalt Concrete (EAC) and 3) 4” SFRC. While both PPC 1121 and EAC are proven successful OSD wearing surfaces, ultimately the newly designed SFRC wearing surface system was selected for its theoretical stiffening potential as a material with fixed elastic modulus compared to PPC 1121 and EAC with dynamic, temperature dependent elastic modulus.

2. Yukon River Bridge In 2013 several PPC 1121 test patches were installed on the Yukon River Bridge deck. The Yukon River Bridge has an orthotropic steel deck with two layers of 2.5” thick timber bolted to the deck as a wearing surface.

For the PPC 1121 trial patches, the top layer of timber was removed, and 18 gauge steel sheeting was bolted

to the bottom layer of timber on which 2.5” thick PPC 1121 was placed. Located in central Alaska, this bridge is exposed to extreme climactic conditions, including air temperatures ranging from -50 °F to 90 °F. April 2017 field inspections of the PPC 1121 test patches show a single crack on the corner of one of the patches.

However, it was confirmed that despite the crack the PPC 1121 remained fully adhered to the steel substrate with minimal signs of distress. Due to the flexibility of the steel sheeting on timber decking, Alaska DOT does not consider the crack to be a serious concern that would preclude PPC 1121 for final consideration as a wearing surface on the OSD deck itself.

Alaska DOT also conducted laboratory testing on 13 different wearing surface systems to analyze traction and tire chain wear damage as well as a life-cycle cost comparison between the 13 systems. Within each subcategory, PPC ranked #1 in non-timber initial capital cost, #1 for all systems in annual average cost, #1 for all systems in chain-dragging surface abrasion and top 3 of all systems for friction and chain-lashing gauge depths.

The Final Report (part 1) ranked PPC 1121 #1 in the final recommendation based on the cumulative laboratory and field testing listed above.

increments and at various load frequencies. Ten million cycles were performed simulating 50 years of maximum fatigue load levels. Static flexural, static failure, tensile pull-out, post-test crack inspection and electrical resistivity tests were also performed.

Notable results from the laboratory testing on PPC 1121 -steel composite are listed as follows: •N o delaminations or debonding was observed in any of the samples • 1 40% increase in composite stiffness in post-cracking samples •4 -8 times increase in apparent modulus across 40-90 °F range vs EAC samples • Electrical resistivity tests on post-cracking samples showed no difference from pre-cracking

3. San Mateo-Hayward Bridge During May 2015 approximately 440,000 SF of 2” thick PPC 1121 was placed on the orthotropic steel deck on the San Mateo-Hayward Bridge high rise section replacing the original Epoxy Asphalt Concrete (EAC) wearing surface that had been in service since 1967.

Final installation of PPC 1121 on this bridge was performed in two full-weekend closures of 55 hours each. During each closure, the existing EAC was removed, steel deck substrate was prepared by shot and sand blasting and 2” PPC 1121 was placed and cured in a single lift.

During the design phase, both EAC and PPC 1121 were considered as replacement materials. A 100’ x 12’ field trial of PPC 1121 installed on the San Mateo OSD in 2014 showed no signs of distress (no cracking, no de-bonding or excessive wear) after 1 year of review. Caltrans has utilized thousands of installations of PPC 1121 on concrete decks in all parts of California, with almost none showing any signs of nearing the end of their service life, and many lasting well over 30 years. While the failure mode for EAC is rutting, shoving and de-bonding, the assumed failure mode for PPC 1121 has shown to be limited to general traffic abrasion over long-term service.

Extensive laboratory testing was performed by the University of Missouri-Columbia on both EAC and PPC. Dynamic loading tests were performed on both wearing surface-steel composite flexural specimens across temperatures ranging from 20 °F – 120 °F in 10 °F

While the history of PPC 1121 on OSD is limited, there have been no reported failures of PPC 1121 on OSD decks. Adhesion achieved by low-viscosity KBP 204 High Molecular Weight Methacrylate (HMWM) primer, linear dynamic modulus throughout temperature ranges, composite stiffening abilities, thermal compatibility with steel substrate, resistance to UV degradation, high tensile strength, extremely high abrasion resistance, resistance to permanent deformation under load and complete impermeability to chlorides, moisture and other contaminants makes PPC 1121 an ideal wearing surface candidate for orthotropic steel deck systems. These attributes and the system’s ability to perform on an OSD substrate are unique to Kwik Bond Polymers PPC 1121 which has been formulated to outperform the basic component requirements typically specified for PPC by including our installation experience and proprietary material technology.