AREMA Guideline Update for RCP and RCB David Matocha Forterra Senior Technical Services Manager Austin, TX

What is AREMA? American Railway Engineering and Maintenance-of-Way Association Rigid Rugged Resilient

Note: “recommended practices….not specifications.” The mission of AREMA is “The development and advancement of both technical and practical knowledge and recommended practices pertaining to the design, construction and maintenance of railway infrastructure.” Note: “recommended practices….not specifications.” Rigid Rugged Resilient

AREMA was formed on October 1, 1997 as a result a merger of three engineering support associations: Roadmaster’s and Maintenance of Way Association (Organized in 1883 primarily to standardize maintenance practices) The American Railway Bridge and Building Association (Formed in 1891 to disseminate ideas on select subjects of mutual interest) American Railway Engineering Association (Organized in 1898 as a forum for development and study of recommended practices, later to be known as the American Railway Engineering Association (AREA). Issued its first Manual of Railway Engineering in 1905.) Rigid Rugged Resilient

AREMA Committee One – Track Subcommittee Four – Culverts Has guidelines for: CMP HDPE PP (2017) GRP (2017) References RCP Rigid Rugged Resilient

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Changes to Part 10: Rigid Rugged Resilient

Changes to Part 10: In 2011, work began to update and improve Part 10 by the concrete pipe industry. By 2014, final edits were completed and approved by Committee 8, Sub- Committee 2 and sent to the full Committee 8 for ballot. In 2015, the final ballot was approved and the new revisions are now part of the 2016 AREMA Guidelines. Rigid Rugged Resilient

Previous List of Symbols: Rigid Rugged Resilient

Current List of Symbols: Rigid Rugged Resilient

Use of Standard Installations: SUCCESS! Rigid Rugged Resilient

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Section 10.3 Design changes that “mirror” Part 16 Reinforced Concrete Box: No more “bottom of tie”, now “base of rail” when measuring the distance from the top of pipe; similar for concrete box. The 40% variable impact load now 1.5 feet below base of rail instead of at 0 feet at bottom of tie; same for concrete box. Revised Figure 8-10-1 (live + impact) is now Figure 8-10-2 and shows additional loading (live, dead, impact, live + dead + impact) similar to loading chart for concrete box. Revised Figure 8-10-3 now shows live load distribution through the soil similar to loading drawing for concrete box. Rigid Rugged Resilient

S U C E !

Work began to review and update Chapter 10 a little over three years ago. Death, Death, Death!

S U C E !

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Changes to Part 10 (cont): Part 10 now includes a commentary, the same as Part 16. Part 10 also has an Appendix A which shows a concrete pipe design problem solved three ways: Calculate D-Load using the Fill Height Tables Calculate D-Load using Figures and Tables Calculate D-Load using Equations REAL SUCCESS! Rigid Rugged Resilient

Why are the changes to Part 10 such a big deal? It makes designing concrete pipe under rail much simpler and gives our industry an opportunity to be more competitive in the market place. REAL SUCCESS! Rigid Rugged Resilient

A major plastic pipe manufacturer made a point to have one of their Technical Marketing Engineers travel to every AREMA Committee 1 Meeting across the US (in addition to every Class I Railroad Engineering Office) to ensure their pipe products were included in the AREMA Guidelines. The concrete pipe industry has been involved in monitoring AREMA Committee 1 Meetings for over 15 years and was successful in slowing down plastic pipe acceptance for years. In fact, the plastic pipe industry had to pay for a test installation at a cost of approximately $100,000.00 and took a year to complete. Clearly they see value in pursuing the railroad business.

Proposed changes to Part 16: Work began in 2014 to start in earnest (once Part 10 was finalized). Committee 8 Subcommittee 1 has proven to be much more resistant to change than Subcommittee 2 was. Currently, Subcommittee 2 has asked for a letter to be sent to the Class I Railroads asking them if they would favor the proposed changes to Part 16 as requested by the concrete pipe industry. Of particular concern is proposed changes to concrete cover requirements and reinforcement. Rigid Rugged Resilient

Graph 8-16-1 Figure 8-16-2 depicts the live load extending outward linearly at a slope of 1 horizontal to 2 vertical, starting at a tie width of 8.5 feet. There is no equation given for this live load distribution, only the figure. Chapter 8, Section 2.2.3 on reinforced concrete design further agrees with this in saying: “Live load from a single track acting on the top surface of a structure with ballasted deck or under fills shall be assumed to have uniform lateral distribution over a width equal to the length of track tie plus the depth of ballast and fill below the bottom of the tie, unless limited by the extent of the structure.” However, the values calculated when using this method with an 8.5 foot tie do not match the values in graph 8-16-1, which appear to be based on an 8 foot tie. Thus, there is no agreement between the live load calculation method given and the graph provided. The ACPA would like to see graph 8-16-1 redone using an 8.5 foot tie instead of an 8 foot tie. Rigid Rugged Resilient

Section 16.3.3   Section 16.3.3 refers to Part 2 for Concrete Design. Section 2.3.2.c only allows steel reinforcing stresses up to 60,000 psi. The ACPA suggests there should be a provision in Section 16 that allows reinforcing strengths up to 75,000 psi, since precast box culverts use wire reinforcement with higher yield strengths. At the very least, it should be increased to 65,000 psi. Rigid Rugged Resilient

Section 16.5.3.a   Section 16.5.3.a requires 2 inches of cover over all steel. The ACPA would prefer this requirement to be 1 inch of cover, unless the box culvert is under less than 2 feet of fill, in which case it would be 2 inches of cover. 1 inch of cover is standard for precast box culverts for highway use. Rigid Rugged Resilient

Section 16.5.3.c Section 16.5.3.c requires a 10 inch slab thickness.   Section 16.5.3.c requires a 10 inch slab thickness.  The ACPA believes the slab thickness should be left up to the Engineer. There already is a deflection limit of L/800 in Section 16.5.3.g; thus ensuring that the slabs do not get too thin. Rigid Rugged Resilient

Section 16.5.4   Section 16.5.4 has requirements for minimum longitudinal reinforcement. The value of 0.4% of the gross area is more than double the existing requirements in ACI and AASHTO for minimum reinforcement. Plus, an increase is allowable if the box is installed under more than 10 feet.  The current requirement in AASHTO and ACI for general concrete design is 0.18% of the gross area. The specific requirement in AASHTO for precast box culverts is even less than this, since this requirement is based on temperature and shrinkage steel, and box culvert sections are short enough that there is not a lot of shrinkage in them. The ACPA believes the 0.18% requirement would be OK, especially since it would still be a big improvement over what is currently required. Additionally, there is no need to increase the minimum longitudinal steel for deeply buried boxes. As noted above, the minimum reinforcement steel is based on temperature and shrinkage requirements. The depth of the culvert has no effect on this.  Rigid Rugged Resilient

Why are the proposed changes to Part 16 such a big deal? Rigid Rugged Resilient

The railroad business is more than just a single culvert under a single track. “At BNSF, we continue to overcome these challenges by being nimble and doing everything we can to adapt quickly to change. The consumer, which drives approximately 70 percent of the U.S. economy, is directly tied to our intermodal business. The fact that consumer spending is currently one of the very few bright spots in our economy will drive growth in our domestic intermodal business, with much of that growth consisting of freight that used to move solely by truck. We believe there are still significant over-the-road conversion opportunities in the intermodal market. And, because of our unique model of partnering with asset based companies to provide the most efficient form of intermodal to shippers, we offer the best solution for capacity.” taken from a 2017 Economic Outlook article in the December 2016 edition of Rail Trends.

We’d approve RCP in lieu of HDPE if it resulted in a cost savings We’d approve RCP in lieu of HDPE if it resulted in a cost savings. They can either do a design analysis based on the pipe profiles, in which case Class IV is acceptable (assuming it calcs out), or they can use Class V everywhere without doing calcs. Nothing lighter than Class IV is permitted anywhere. Here’s the relevant section from the specs (02437 Reinforced Concrete Pipe): PART 2 - PRODUCTS 2.1 PIPE CULVERT MATERIAL A. Pipe culvert material must meet the standards set forth in Chapter 8, part 10 of the current AREA Specifications. RCP pipe culvert materials shall be furnished in lengths not less than 4 feet. Material is to be new material. B. All pipe material shall be designed for Cooper E80 loading and no pipe lighter than Class IV will be permitted. The minimum factor of safety against formation of a 0.01 inch crack shall be 1.0. In lieu of design analysis, the Contractor may furnish Class V pipe for installations with 14 feet maximum cover.

Forterra gave the Engineer and Contractor a copy of the Texas DOT thermoplastic pipe spec which requires non-combustible pipe ends and safety-end-treatments; a limit of 36” diameter and no more than two barrel crossings. Also helped that the plans for the road from the highway to the intermodal yard required RCP only; and that the City of Laredo also calls for concrete pipe only. A copy of the then proposed revisions to Part 10 was given to the Engineer and Contractor as well. Forterra also took a plan set and did D-Load calculations of all storm drain pipe and showed where many of the installations were fine with Class I or II pipe. The Engineer and Contractor ultimately approved the use of Class III pipe for a majority of the project.

Project quantities: 3,300 LF of 24”, 30”, 36” and 42” 5,600 LF of 48” The purchase order for the project including pipe, box, and precast was over $1.4 million! Cha – Ching!