Opening of Qualifications - WWTP CSO Tank RFQ Guaranteed Savings Contract Proj No. 121-071-A - Bowen Enigneering

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BOWEN 160 Route 41 I Gap, PA 17527-9410 4,DutchlandLLC Phone 717.442.8282 1 Fax 717.442.9330 Innovation. Experience. Eco-friendly. www.dutchlandinc.com ®OO South Bend Indiana A W WA D 1 1 S Advantages July 5, 2023 Bowen Engineering Corporation 8802 North Meridian St. Indianapolis IN 46260 ATTN: Steve Nutt Below is a list of AWWA D115 (Dutchland type tank) over AWWA Diio (wire wound tanks). Please feel free to use any of these points in your South Bend RFQ submission. • D115 construction allows for a more open construction site since manufacturing of precast elements occurs offsite. Wire wound tank construction generally precast and store wall panels onsite. • Prestressing D115 tanks typically require less space than winding prestressing wire. This can result in lower excavation and SOE costs. • D115 tanks have no cold joints. D115 wall panels are cast in a single pour. Wire wound precast wall panels are erected and then multiple layers of prestressing wires are applied and coated with shotcrete, which creates cold joints. • Dutchland D115 precast panels use self -consolidating concrete (SCC) with air entrainment but have very little air entrapment. Air entrapment is inherent in the shotcrete process. Poured SCC is very dense, durable concrete. Air entrapment can result in concrete that is more porous than SCC, and therefore less durable. o Air entrainment is designed into concrete to enhance durability. Air entrained concrete has discrete, not -connected air bubbles within the cured concrete. It contains air, but is not porous. o Entrapped air is introduced when shotcrete is sprayed onto the wall surface. Air voids can be connected to each other, which can lead to porous, less durable concrete. • Precast D115 wall panels are cast in forms and then cure in an unrestrained condition in the yard. Concrete shrinks as it cures. Unrestrained precast panels allow the concrete to shrink with less cracking compared to a final shotcrete layer (which is not prestressed). • Plastic ducting and pressure grouting incorporated in DI15 prestressing tendons provide better corrosion resistance to steel strand than shotcrete applied to wire prestressing. • Precast D115 panels are cast in shops with very extensive QC/QA procedures. • Dutchland precast D115 panels are cast in temperature -controlled buildings, which is a less weather dependent type of construction than wire winding, in which all operations are performed outdoors onsite. • Precast DI15 tanks can more easily accommodate large penetrations in tank walls, as well as external structure like drop boxes. Following is a rough preliminary duration schedule to design, manufacture and construct the South Bend CSO tank. Bowen and Dutchland can work together to improve most of the schedule items shown below. Preliminary Durations: Description Duration Location Notes Submittal Drawings 8 Weeks Offsite From start of design ENVIRONMENTAL ENGINEERING CONCRETE STRUCTURES