CDBI
C ompact D owel B ar I nserter
A Publication of Guntert & Zimmerman Const. Div., Inc., Ripon, California U.S.A.
Since concrete slipform paving began, there has been a need for mechanical Dowel Bar Inserters (DBI) to eliminate the costs and inconveniences associated with dowel supporting baskets. G&Z and its associates pioneered DBI technology starting in the late 1970s.
1st Generation DBI Technology G&Z’s 1st Generation DBI Technology required long bolster extensions be added to a standard slipform paver frame to accommodate a DBI and the following Oscillating Correcting Beam (OCB). A large crane was required for assembling and dismantling the non-modular paver and DBI for transport. High mobilization costs limited the DBI’s economic attractiveness to only large mainline concrete paving projects. Dowel Bar Inserter
Trailing Sideform
Long Bolster Extensions
Confining Pan Dowel Distributing Oscillating Cart Correcting Beam
Trailing Finishing Pan (Optional)
2nd Generation “Compact” DBI Technology
G&Z Compact Dowel Bar Inserter
G&Z’s Dowel Bar Inserters
When developing G&Z’s 2nd Generation Dowel Bar Inserter, G&Z focused on making successful DBI technology even better. G&Z’s goal was to improve the DBI design so DBI technology would be economical to use on smaller projects. G&Z’s Compact DBI Technology resulted in offering the following advantages and improvements over the 1st Generation DBI: The patented CDBI structure is now a single, self-supporting module designed to speed assembly, disassembly and width changes. The optional CDBI self-loading kit eliminates the need for a crane to add / remove the CDBI from the paver or load / unload a trailer. These tasks now take a few hours instead of days! The CDBI quickly mounts on the rear of a standard G&Z Four-Track Slipform Paver without any modification and does not require long bolster extensions even on high production paving operations. This patented feature allows conversion back and forth between DBI and non-DBI paving in a matter of hours. The patented CDBI dowel distributing Chain Feeder System reduces the feeding system profile and greatly improves the feeding system’s speed and reliability as compared to the old dowel distributing cart system.
Dowel Bar Inserter
Standard Bolster
Dowel Chain Feeder Trailing Sideform (not shown)
Confining Pan
Oscillating Correcting Beam Trailing Finishing Pan (Optional)
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DBI Technology
G&Z has been in the forefront of DBI technology since the late 1970s. Since then, G&Z has been the leader in DBI technology by continuously improving the state of the art, based on extensive field experience. This leadership edge insures G&Z DBI users to have the highest productivity, mobility, ease of width change, reliability, user friendliness, smoothest rides and best dowel bar accuracy possible. European Two-Track Paver / DBI Prototype In the late 1970s, G&Z’s licensee, SGME Herentals, Belgium, performed the first successful two-track paver-mounted DBI system trials in Belgium and Switzerland. The early G&Z-SGME dowel bar inserters were mounted as an attachment off the back of a two-track G&Z Paver. This was the first successful paver-mounted DBI System in the World!
One of the first successful paver-mounted prototype DBI systems in the world.
European Four-Track Paver / DBI Prototype In 1983, the first G&Z-SGME four-track paver specifically designed for use with the new G&ZSGME DBI Technology was delivered in Germany. The new technology was developed for better balance, improved smoothness results and selfloading advantages.
G&Z-SGME S1200 Paver with DBI working at 37.7' (11.5m) wide in Germany.
U.S.A. Four-Track Paver / DBI Prototypes In 1987, two G&Z prototype DBI units were mounted on four-track pavers and successfully introduced in Texas and Wisconsin, U.S.A. Because of the success of G&Z’s dowel bar insertion technology in these two states, G&Z’s DBI Technology spread rapidly across the U.S.A., Canada, and the rest of the world.
G&Z S1500 Paver with DBI working at 38' (11.58m) wide in Wisconsin, U.S.A.
Compact Dowel Bar Inserter (CDBI) Prototype In 1999, G&Z introduced a redesigned DBI unit. Initially designed to fit G&Z’s S850 QUADRA Paver, the CDBI was designed for high mobility, ease of transport & width change, and incorporated many new and improved features. CDBI technology is available on all G&Z Four-Track Slipform Pavers.
G&Z S850 Paver with CDBI working at 24' (7.31m) wide in Colorado, U.S.A.
G&Z Compact Dowel Bar Inserter
G&Z The Market Leader
is
Found
Precision Insertion Forks & Magazine Guides help insure consistently high dowel bar location accuracy. The CDBI can be easily and economically rearranged for different dowel centers, dowel length, diameters and depth.
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Details
CDBI Mounts on Standard Four-Track Paver, with no modification, providing the optional DBI Preparation Kit is selected. No long bolster extensions are required. Conversion of the paver between DBI and non-DBI use can be accomplished in hours.
Guillotine Trailing Sideforms (optional) hydraulically telescope up and down to accommodate a wide range of slab thicknesses during paving to avoid concrete leakage under the sideforms. The sideforms hydraulically open and close for ease of morning starts.
Second Pumping Unit is not required as all hydraulic and electrical requirements for the CDBI are taken from the paver power unit. CDBI is shown with optional TFP. Note: No longitudinal, oscillating finishing float is required for highway paving.
Hydraulic Crane (optional) with telescopic boom is available to lift dowel bundles on to the paver while paving. A wireless crane control is provided for the crane operator.
G&Z Compact Dowel Bar Inserter
Success
is
Found
Trailing Finishing Pan (TFP-optional) with adjustable edgers is towed behind the OCB to enhance surface smoothness and to help insure sharp edges even while inserting side tie bars.
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Details
Narrow Profile Design makes the CDBI an ideal attachment to the G&Z Four-Track Paver for urban reconstruction paving under traffic conditions where minimal room is available for paver trackline or sidefeeding concrete.
Spreader Plow for OCB (optional) redistributes concrete in front of the OCB and is used for moving concrete uphill in super elevated curves. The plow is used periodically for mixing up the concrete roll.
Oscillating Correcting Beam (OCB) is typically the only mechanical finishing device required to refinish the concrete surface after insertion. The precision built OCB includes bolt-on and replaceable wear plates on the bottom and leading edge.
Side Tie Bar Inserter (STBI-optional) inserts straight or bent side tie bars. The narrow profile STBI is located behind the rear crawler track and mounts off the Trailing Finishing Pan Edger making them ideal for tight trackline conditions.
G&Z Compact Dowel Bar Inserter
Success
with
G&Z’s CDBI
Material Savings: Elimination of supporting baskets for dowel bars. Labor Savings: Elimination of a 10 to 12 person crew and support equipment required to set dowel baskets on a high production paving operation. Equipment Savings: Elimination of placer spreaders and required haul road by hauling and dumping concrete on grade directly in front of the paver.
High production, mainline highway paving is shown pouring plain concrete with dowels under strict profilograph specification using CDBI. Concrete trucks are dumping on grade directly in front of the paver.
Urban paving under traffic conditions is feasible because of the narrow profile design of the G&Z Paver with CDBI. The room required for the paver crawler track is minimal. The need for side feeding concrete is eliminated.
Integral curb is possible when using the CDBI with little or no modification. The high mobility of a G&Z Paver with CDBI makes it economical even on small jobs.
Airfield paving of thick slabs is possible with G&Z Pavers equipped with CDBI because of their robust construction, superior sideform design and other features.
Traditional Concrete Paving
On a high production concrete paving job, one or two concrete placer spreaders are required to receive concrete and spread it over the top of the dowel baskets. A haul road next to the paver must be built and maintained.
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Dowel Basket Assemblies
On lower production concrete paving jobs, a concrete placer can be used and dowel basket assemblies walked into place behind the concrete placer and secured to the subgrade just ahead of the paver.
G&Z Compact Dowel Bar Inserter
Cost Saving Advantages
G&Z’s patented dowel chain feeder rapidly and reliably loads dowels into the DBI system. G&Z’s unique combination of DBI confining pan, trailing sideforms and four vibrating forks per bar help insure good consolidation and homogeneous concrete around the inserted dowel bars. This is accomplished while minimizing the disturbance to the surrounding concrete surface. Step 1: Dowel bars are manually loaded into the patented chain feeder system one bar at a time. Dowels can be fed from either side of the machine.
Step 2: When the dowel distributor is fully loaded, dowels are rapidly distributed across the DBI confining pan by the chain feeder, and the rolling dowels are dropped into any open magazine holding slot above the plastic concrete to await insertion. Step 3: At the start of the insertion cycle, the magazine slots shift allowing the dowels to drop from their holding slot through the confining pan guides to the top of the plastic concrete where they await insertion by the four vibrating forks per bar. Guide “ fingers” hold the dowel in the proper position prior to insertion.
Step 4: The roller supported inserter beam and confining pan (which floats on the concrete surface) are towed by hydraulic cylinders immediately behind the slipform paver pan. The DBI inserter beam with confining pan stays stationary in reference to the joint during the insertion process while the paver continues to advance. Step 5: Dowel bars are inserted into the concrete through slots in the confining pan to a preset depth with a combination of light hydraulic pressure and vibration. Precision insertion forks impart two frequencies of vibration to each bar (inner two forks 6000 vpm / outer two forks 3000 vpm).
Step 6: Once the insertion cycle is complete, the towing hydraulic cylinders retract the roller supported inserter beam and confining pan back to its resting position at the rear of the slipform paver pan; then the DBI is ready for reloading. The following OCB refinishes the concrete surface blemished by the insertion process with little or no additional finishing required.
G&Z Compact Dowel Bar Inserter
How G&Z’s DBI Works
Self-Loading CDBI for Long Distance Transport: CDBI module can be equipped with optional self-lifting jacks and small gas engine power unit. With the patented self-lifting option, the CDBI can load or unload without a crane onto a trailer in a single load in a few hours.
High Maneuverability for Short Distance Walking: G&Z’s exclusive 90º steering and counter-rotation capability designed for its pavers allows a G&Z paver with CDBI to walk and steer sideways through tight confines including bridge columns or other obstacles found on job sites.
Exceptional Accuracy Inserted dowel bar accuracy can be checked with cover meters or MIT scanning technology. According to Missouri and other DOT / Industry studies, “Dowels placed with G&Z’s mechanical DBI are placed as accurately or better than dowels placed using baskets.” In a recent project where G&Z’s CDBI was used, bar accuracies were checked by MIT Scan and found to be “among the best ever for either DBI or basket projects.”
G&Z Compact Dowel Bar Inserter
Exceptional Mobility & Maneuverability
Optional Equipment Automatic Paint Marking System Hydraulic Crane for lifting dowel bundles Computerized Crown Transition Control for one or more profile breaks Loading Magazine for high speed paving operation Integral Curb Forming Kit Trailing Sideform Extensions for thick airfield pavements
Self-loading Kit with hydraulic jacks, pedestals, and small gas engine power unit Concrete Spreader Plow for Oscillating Correcting Beam Guillotine Trailing Forms with hydraulic telescopic ability Trailing Finishing Pan with Edgers
Notes: To accept the CDBI without modification and to eliminate the need for a second / separate power unit for the CDBI the optional DBI Preparation Kit for the G&Z Paver must be selected at the time of order. Control over the concrete mix design, namely optimization of combined aggregate gradations, aggregate particle shape, concrete uniformity, and workability, is essential to achieve smooth paving results.
Manufactured under one or more of the following U.S. or Foreign Patents: 4,433,936; 4,483,584; 0051885; 6,390,727; 6,390,726; 6,176,643B1; 5,135.333 and 117323 and Patents Pending. Some items shown may be optional. Guntert & Zimmerman Const. Div., Inc. will custom build any machine or accessory to suit your particular job requirement. G&Z reserves the right to make improvements in design, material, and/or changes in specifications at any time without notice and without incurring any obligation related to such changes. Printed in U.S.A. 2007 G&Z Order #118765
Guntert & Zimmerman Const. Div., Inc. 222 East Fourth Street Ripon, California 95366 U.S.A. Ph (209) 599-0066 Fax Toll Free 1-800-733-2912 Email gz@guntert.com Web
(209) 599-2021 www.guntert.com