Anti-Trust Statement
http://www.concrete-pipe.org/
A joint effort of the Texas Concrete Pipe Association and the Texas Department of Transportation
What brought this about? The TxDOT organization consists of 25 districts which operate independent of each other. This allows them to have their own unique inlet and manhole designs resulting in literally hundreds of different designs for us to build to The majority of the designs were cast in place and could not be accommodated with our current molds We were allowed to submit our alternate designs but this was a lengthy process and usually led to confusion and delays in the job Differences in the structures from one district to the next led to errors in manufacturing and errors in installation Differences in terminology from one district to the next led to errors in manufacturing and errors in installation Some of their designs did not appear to be traffic rated to nationally recognized standards
What issues did this cause for us? Difficult to purchase and maintain fixed molds for each design Use of labor intensive panel-molds cut efficiencies No economy of manufacture (Production slowed due to forming a different structure every time) Repetitious engineering of unique designs in order to comply with current regulation Increased labor for drafting with preparing submittal drawings Increased labor for sales and / or project coordinators due to drawing review and scheduling Created excessive inventories of job specific structures Hampered customer relations due to product availability Hampered customer relations due to charges for un-used product
What issues did this cause for the contractor? Created confusion installing the same type of structures from different manufacturers Created confusion installing the same type of structure in different districts Increased labor due to submittal processes Delays in project schedules due to lengthy submittal processes Delays in project schedules due to lengthy production times from the manufacturers
What issues did this cause for TxDOT? Increased labor due to submittal processes Increased cost of materials Increased cost of installations Increased citizen complaints
Inlet Type F - Pharr District
Curb & Grate Inlet Type I Dallas District
Type A&B Manhole - Houston District
Type A&A1 Manhole - Pharr District
Type M Manhole Bridge Division
TXDOT Districts
Summary: The purpose of the Standard Inlet & Manhole Program, a joint effort of the Texas Concrete Pipe Association and the Texas Department of Transportation was to simplify the layout protocol, selection, manufacture and installation of precast concrete inlets and manholes in the state of Texas and by so doing reduce costs, normalize expectations and improve installation. To those ends, the necessary styles were selected, standard geometries developed and minimum levels of reinforcement and concrete strength determined. The resulting standards can be found in this guide. This guide was prepared to assist in the use and maintenance of this program. This guide and program will be maintained by a joint task force comprised of personnel from TxDOT and the Texas Concrete Pipe Association.
So how does it work? Guide consists of: Procedures Forward Summary Overview Definitions Layout Protocol Installation Inspection Precast Standards Iron Standards Annex Tables, Charts, Reference Information
Engineering covers these main points: Square / Rectangle Structures Nominal 25 from top of floor slab to grade. broken into two divisions: from 0 to 15 feet and 0 to 25 feet. All square and rectangular bases were designed with four way thin wall panels. All thin wall panels and holes are round and do not cut into floor, walls or within six inches of the joint above. Penetrations through corners are not allowed. Penetrations are center wall at 90 degrees plus or minus 7 degrees. Reducing slabs available for all sizes other than 3x3 and 4x4.
Base Dimensions (W X L ) Minimum Inside Height Increment Risers Available Min. Height Reducers Available Curb Inlet Grate Inlet Barrier Inlet Flat Slab Ring & Cover MH Cone Area Drain 3 x 3 3 6 3 6 X X X X 4 x 4 4'6" 3 6 X X X X 3 x 5 3'6" 3 6 X X X X X 4 x 5 4'6" 3 9 X X * X X X X 5 x 5 5'6" 3 9 X X * X X X X X 5 x 6 5'6" 3 9 X X * X X X X 6 x 6 6'6" 3 12 X * X X X 8 x 8 8'6" 3 12 X * X X X 48 round 2 6 3 12 ** X X X 60 round 3 6 3 12 X ** X X X 72 round 4 6 3 12 X ** X X X * Note that grates may be used, but the only sizes of grates are 3x3, 4x4 and 3x5. ** Note that grates are available for ring and covers.
That covers the bases, reducers and risers. Now for the lids: Curb Inlets Grate Inlets Stage One (allows for custom lids) Solid lids above and below ground (no openings) Specialty lids Median Barrier Drain Overpass Drain Area Zone Drain
The naming convention: Type PCU Type PCO Type PSL Style SL Style RH Style RC Style RG Style SH Style S1 Style FG Style SFG Type PRM Type POD Type PAZD Style SL Style RC Style RG Style FG Type PMBD 17 variations of lids are available.
Type PCU Precast Curb Inlet Box Under Street
Type PCO Precast Curb Inlet Box Outside Street
precast curb inlet box under street Type PCU precast curb inlet box outside of street Type PCO precast slab lid with lifting devices Type PSL solid lid Style SL solid lid with round hole Style RH solid lid with ring & cover (r&c cast in) Style RC solid lid with ring & grate (r&g cast in) Style RG solid lid with square or rectangular hole Style SH solid lid stage 1 (exposed rebar) Style S1 solid lid with square or rectangular frame & grate cast in Style FG solid lid sloped with square or rectangular frame & grate cast in Style SFG precast round manhole Type PRM precast overpass drain Type POD (current TxDOT Type AZ & AZR) precast area zone drain Type PAZD area zone drain with solid lid Style SL area zone drain with ring & cover Style RC area zone drain with ring & grate Style RG area zone drain with frame & grate Style FG precast median barrier drain Type PMBD
Round Product:
Engineering covers these main points: Cast or cut holes that do not cut into floor or less than the wall thickness of the product from an adjacent hole or the joints above and below. Maximum penetration diameter (as opposed to pipe diameter) for 48 round product is 32. Maximum penetration diameter for 60 round product is 40. Maximum penetration diameter for 72 round product is 54. Round manhole product shall comply with ASTM C 478 latest revision. Reducing slabs are available for all sizes other than 48 diameter.
Additional items Steps and ladders - Cast in steps or ladders are considered a safety hazard: they are difficult to impossible to adequately maintain. Furthermore they can become an attractive nuisance. Therefore cast in place steps are not a part of the precast standards. Inverts and benching - Slight variations in line and / or grade of pipelines can make precast inverts on rigid pipe lines extremely difficult to meet. Therefore, inverts and benching, if desired, must be fabricated by the installation contractor in the field. Field storage - When receiving product deliveries, stockpile the components for a station adjacent to the station where they will be installed.
Installation
Installation
Installation
How does the program help us? Once operational, we will have 17 standard designs to manufacture to Designs will be specified as precast with CIP as the alternate The ability to purchase and maintain fixed molds Less use of labor intensive panel molds means better efficiencies Economy of manufacture can be realized Engineered once and done Reduced labor for all departments Fewer write-off s of unused job specific products Ability to stock standard products Quicker turnaround times Improved customer relations and TxDOT relations
How does the program help us?
How does the program help the contractor? Less time spent on submittal review Less time spent on job scheduling Normalized expectations between manufacturers and districts means: Less employee training Faster installations Better installations Less down time or equipment mobilization when job changes arise
How does the program help TxDOT? Less time spent on submittal review They now have a precast option to design from Simplified inspection Fewer change orders Fewer citizen complaints Ease of mind that designs have been engineered to perform at their expected levels
How does this help everyone? Specifier s Time Manufacturer s Time Contractor s Time Inspector s Time
??? Questions???