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Coppell Trade-CS050706 (2) 2~4 6~8 7878 07/06/05 15:55 FAX 214 630 7070 TERRACON CONSULTANTS ~001 05~07/~805 15:48 2143736588 P&GE 81 hg 4TEE EN6iNEERINI~ 6440 N. Central F. xl~y. * Sul£e ,~ ~4 Dallas, Texas 7520~ Facsimile Cover Sheet To: Charlene La Matting, PE Company: City of Coppell Phone: 972-304-7044 Fax: 972-304-3570 From: Day~o B/'M acatee Phone: 214-37~-1180 Fax: 214-3 6580 . Date: 5/7~05 ~ Pages including this cover page: ~ W Comments: Charlene, Here's my letter requesting (1) no lime, and (2) use of fly ash. Will you please review it and let me know if you have any questions, ~-~v~i~u ptease provide the appropriate docuroentation to Charlene to suppor~ our request? Thank yo~, Cc; Chris Eddy 972-630-7070 Al Sorrels 972-24,1-7955 Jori Jacobson 972-401-1399 CONFtDENTtALITY NOTICE: The information cortteined in th:- facstmlte message is legadf~y privileged and ~on6denUal i~formeUon, 07/06/05 15:55 FAX 214 630 7070 TERRACON CONSULTANTS ~002 05/0~/2005 1~:48 2543736580 M&OATEE ENG PAGE 82 MACATEE EN/i/,,NEERIN/ May7,2005 City of Coppcll 255 Parkway Boulevard Co!~pell, Texas 75019 Arm: Ketth Marvin, P.E. Re: Sub,adc Preparation & Paving Sp~ifications Request for Modification Coppell Trade Center Dear Keith, Please aece~ this letter as our formal request to modify the subgtade preparation and paving specificatior~ on the referenced pmiect. Our request is basext on re¢ommendatiqns made by HBC/Termeon. According to the reeommendatlona contained in the Gco~chnical .~lg~nc~ring Report prepared by HBC/Terracon for The Holt Corapm:des (I-iBC Job No. 9404523) dated January 14, 2005, lime stabilization is not necessary for the paving subgrade. The last sentence ia the next-to-last paragraph on Page 14 states "Rigid (concrete) pavements may be placed on an unstabiliz~l, properly compacted subgrade." The next-to-last paragraph on Page 13 states "On-site or similar imported soils piaced ,~Sthin the building foo~rint and beneath parking areas should be compacted to a minimum of 95 percent of ASTM D 698 maximum drg cleasity at or above optimum moisture content." Based on these recommendations, we request Coppelt's req~fit~merst for llme stabilization under paving - including fire lanes, ~xuck docks and parking areas - b~ deleted. la a subsequest letter report prepared this week, I-IBC/Terraeon has designed a concrete mix design which utili~.es fly ash. Subject to the recommencations and qualifications contained in their report, we request fly aah be allowed in the concrete mix design for onsite paving. we will have HBC/Terracon pro,fide full copies of both. of the rcfarenced z~ports. Please call us at the amber above or C}tris Eddy fftBC/Termcon) at 214-630-1010 if you need any addhional infomlation. Sincerely, C¢: Chris Eddy (I-IBC/Tcrraeon) A1 Sorrels (The Holt Companies) Jan Jacobsen (McFadden & Miller) 07/06,'05 15:55 FAX 214 630 7070 TERRACON CONSULTANTS ~003 May 05, 2005 lrerracan Consulting Enginesrs & Scientists 8901 Carpenter Ftwy, Suite 100 Oallas, Texa~ 75247 Phone 214.630.1010 Fax 214.$$0.?070 Coppell Trade Center LP 5055 Keller Springs Rd., Ste $00 Addison, Texas 75001 At-[n: Mr. Al Sorrells Re: Concrete Mix Design Review Coppell Trade Center Building C Coppell, Texas HBC/Terracon Report No. 94051190.0002 Dear Mr. Sorrels:. We have reviewed the concrete mix design, (TXI Mix No. 8206) submitted by McFadden & Miller, Inc., for firel;~ne and general pavement use at the above referenced project. Our comments regarding the mix are documented in the attached report. Thank you for the opportunity to provide this service. Please feel free to call if I may answer any questions or assist in any way. Yours truly, HBCrrerracon Delivering Success f~r Clienta and Employees Since Mere Than 60 Offices Nationwide 07/06/05 15:55 FAX 214 630 7070 TERRACON CONS[LTANTS __.~004 4000 psi for Pavement Re. uired Project Documents Compressive Stren(~th 4000 psi Submitted TXI 8206 Slump_ 3-5" Coarse Max. W/C Admixtures Aaa. Ratio C260 C494 Max. 1" 4000 psi 3-5" 1" 0.457 3-6% Ok 3-6% YES SUBMITTED HISTORICAL DATA TXI MIX NO. 8206 Average 28-Day Strength: 5490 psi Standard Deviation = 560 psi N=30 ACI 318-02 Section 5.3.2,1 f'cr = 4000 + (1.34 x 560) = 4750 psi or f'cr = 4000 + (2.33 x 560) - 500 = 4805 psi REQUIRED MINIMUM AVERAGE STRENGTH = 4805 psi Margin of Extra Performanoe = 685 psi Comments: This mix contains 6.0 sacks total cementitious material; 4.8 sacks (451 lbs.) of Type 1/11 cement and 113 lbs. of fly ash (20% by volume); 1" crushed stone for the coarse aggregate; ASTM C 494 water reducing admixture, and ASTM C 260 air entraining agent; and is designed for a maximum 5" slump at the point of deposit , It is designed for pavement use. The submittal did not provide: the source of Cement and Fly Ash, maximum elapsed time before discharge after introduction of water and cement, and minimum concrete temperature. Conclusion: The cement/fly ash ratio appears to be in compliance with the current edition of NCTCOG Standard Specifications. The strength requirement meets the minimum criteria per ACI specifications and project specifications. Terracon feels that this submitted mix should be adequate for pavement use on this project, as long as the maximum slump is not exceeded, the proper placement and curing temperatures are met and batch to placement times are not exceeded. Final acceptance of this mix must be by the civil enaineer. 07/06/05 15:56 FAX 214 630 7070 TERRACON CONSULTANTS ~005 Coppell Trade Center - Building C Job No. 94045423 January 14, 2005 '1 rer r'er.=n Sefllement of the back'fill should be anticipated. Piping and conduits through the fill should be designed for potential soil loading due to fill settlement. Flatwork, sidewalks and pavements over fills may also settle. Back'fill compacted to the density recommended above is anticipated to settle on the order of one percent of the fitl thickness. Utilities Care should be taken that utility trenches are not left open for extended periods, and they are propedy backfilled. Backfilling should be accomplished with properly compacted on-site sandy clay soils, rather than granular materials. A positive cut-off at the building line is recommended to help prevent water from migrating in the utility trench backfill. Earthwork The on-site soils are suitable for use in site grading. Imported fill material placed outside the building area should be a clean soil with a liquid limit less than 50 percent and no rock greater than 4 inches in maximum dimension. Imported fill materials placed within the building footprint and within 10 feet of the building perimeter should be a clean soil with a liquid limit less than 40 percent and no rock greater than 4 inches in max[mum dimension. All fill materials should be free of vegetation, debris and other deleterious materials. Prior to placing any fill, the areas to receive fill will need to be stripped and grubbed. Any soft or pumping areas should be excavated to a firm subgrade and properly backfilled. The subgrade should then be scarified to a minimum depth of 6 inches and compacted to a minimum of 95 percent of ASTM D698 maximum dry density at or above .the optimum moisture content as determined by that test. The fill materials should then be spread in loose lifts, less than 9 inches thick and uniformly compacted. On-site or similar imported soils placed within the building footprint and beneath parking areas should be compacted to a minimum of 95 percent of ASTM D 698 maximum dry density at or above the optimum moisture content. Fill placed in landscape areas can be placed at a minimum of 93 percent of ASTM D 698 near optimum value. If filling is suspended and the subgrade becomes desiccated or rutted, it should be reworked prior to placement of a subsequent lift. Final slopes should be as flat as practical to reduce the possibility of creep and shallow slides. Particularly adjacent to site improvements, slopes of 4H:IV or flatter are preferred. Site improvements should be maintained away from the crest of slopes in order to reduce the affects of creep or shallow slides. 13 07/06/05 15:56 FAX 214 630 7070 TERRACON CONSULTANTS ~006 Coppell Trade Center - Building C Job No. 94045423 January 14. 2005 'l reft-re:un Drainage All grades must be adjusted to provide positive drainage away from the structures. Water permitted to pond near or adjacent to the perimeter of the structures can result in soil movements that exceed those discussed in this report. Open ground should preferably be sloped at a minimum of 5 percent grade for at least 10 feet beyond the perimeter of the building. Flatwork and pavement wilt be subject to post construction movement. Maximum grades practical should be used for paving and flatwork to prevent areas where water can pond. In addition, allowances in final grades should take into consideration post-construction movement of flatwork, particularly if such movement would be critical. Consideration should be given to preparing the subgrade as diSCUSSed in the Slabs-on-Grade/Flatwork section of this report in sensitive areas. Where paving or flatwork abuts the structures,' care should be taken that joints are properly sealed and maintained to prevent the infiltration of surface water, Planters located adjacent to the structures should preferably be self-contained. Sprinkler mains should be located a minimum of 5 feet away from the building line. If heads must be located adjacent to the structures, then service lines off the main should be provided. Roof drains should discharge on pavement or be extended away from the structures. Ideally, roof drains should discharge to storm sewers by closed pipe. Area Paving Pavement Subgrade Treatment ecbgrade materials at this site are anticipated to consist of sandy clay and clay soils. These ils are subject to loss in support value with the moisture increases, which occur beneath vement sections.' They react with hydrated lime, which serves to improve and maintain air support value, Lime stabilization is recommended beneath flexible (asphalt) pavement lions. Rigid (concrete) pavements may be placed on an unstabilized, properly mpacted subgrade. "'~A minimum of 6 percent hydrated lime (TxDOT Item 264), by dry weight, should be used to treat the sandy clay and clay subgrade soils. The lime should be thoroughly mixed and blended with the top 6 inches of the subgrade (TxDOT, Item 260). Stabfliza'don should L extend a minimum of I foot beyond the edge of the pavement. 14 07/06/05 15:56 FAX 214 630 7070 TERRACON CONSULTANTS ~007 Coppell Trade Center - Building C Job No. 94045423 January 14, 2005 The subgrade, stabilized or unstabilized, should then be uniformly compacted to a minimum of 95 percent of ASTM D698 maximum dry density between -1 to +3 percentage points of the optimum moisture content. The subgrade should be protected and maintained in a moist condition until the pavement is placed. Pavement subgrades should be gradeci to prevent ponding and infiltration of excessive moisture on or adjacent to the pavement subgrade surface. Pavement Sections Both asphalt and concrete pavement sections are presented below. They are not considered equal. Over the life of the pavement, concrete sections would be expected to require less maintenance. Five inches of asphaltic concrete should be adequate in parking lots serving only automobile traffic. This should be increased to 6 inches for drives subject to more frequent automobile traffic. The section should consist of a two-inch surface course similar to TxDOT Type D and a base course similar to Type B. The coarse aggregate in the sudace course should be crushed limestone rather than gravel. irtand cement concrete is recommended in areas subject to truck traff[~ and should vide exce ant service for other pavement areas. In employee parking lots and other eas not subject to trucks, a minimum of 5 inches of 3,000-psi concrete on an unstabilized bgrade is recommended. In areas subject to truck traffic, the following table summarizes est mated number of allowable daily repetitions of a fully loaded tractor-trailer rig. The ctions are based on the use of a minimum 28-day compressive strength of 3,500 psi and 20-year design life. 6" Concrete 5 7" Concrete 40 8" Concrete 90 The pavement will be subject to some movement due to volume changes in the clayey soils. Flat grades should be avoided with positive drainage provided away from the pavement edges. Backfilling of curbs should be accomplished as soon as practical to prevent ponding of water, 15