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Town Center L1B2-SY 970512 + n a 111111:11111111111111111115GEOSCAS, eglielitillilillillitillill Sa a ! r ili a P \ GEOTECHNICAL&MATERIALS ENGINEERS Q t1Ok tip,, May 12, 1997 �` mil.', ' cy 1 ', , . Malouf Interest, Inc. 7' ' ' 3811 Turtle Creek Boulevard, Suite 1800 Dallas, Texas 77219 Attention: Mr. Matt Malouf Reference: Geotechnical Investigation Proposed Shopping Center Sandy Lake and Denton Tap Road Coppell, Texas GET NO.: 97DG1146 Dear Mr. Malouf: GEOSCIENCE ENGINEERING& TESTING, INC. is pleased to submit this report for the above referenced project. This study was authorized by you on April 23, 1997. This report briefly describes the procedures employed in our investigation and presents the conclusions and recommendations of our studies. We appreciate the opportunity to work with you on this phase of the project. If you have any question concerning our work or require additional information, please contact us. •• • tiOF TE,0%, c' 6, Very Truly Yours, i */• l, ••*�+, */ R SSOUNA /1,26fri, fri„,,,,„,.....„----3 I� .0,�.9 819660:Wi Russ M. Hassouna, MSCE., P.E. it ••:cO/STER.= Senior Engineer evt s`/0`w� r Id" t -°-•■■•vg,,,,!;:,, M-S C(g- Jim A. Palavan MSCE., P.E. Principal Engineer 405 East 20th Street 2630 Northaven Rd., Ste. 106 13134 Lookout Run,# 2 Houston,Texas 77008 Dallas, Texas 75229 San Antonio,Texas 78233 (713) 861-9700 (972) 488-3500 (210) 657-9700 GEOTECHNICAL INVESTIGATION Proposed Shopping Center Sandy Lake and Denton Tap Road Coppell, Texas Reported to Malouf Interest, Inc. Dallas, Texas Prepared by Geoscience Engineering & Testing, Inc. Dallas, Texas PROJECT NO.: 97DG1146 May, 1997 GEOSCIENCE ENGINEERING AND TESTING, INC. Malouf Interest, Inc. GET NO.: 97DG1146 May 12,1997 Page 1 INTRODUCTION Geoscience Engineering and Testing,Inc. (GETI)hereby submits this report of Geotechnical Investigation of subsurface conditions at the site of the Proposed Shopping Center located at Sandy Lake and Denton Tap Road in Coppell, Texas. GETI's investigation was authorized by Mr. Matt Malouf with Malouf Interest, Inc. PURPOSE The purpose of the Geotechnical Investigation was to determine the subsurface soil conditions on the site of the Proposed Shopping Center with particular reference to the design of the foundation for the structure and any pavement recommendations. FIELD INVESTIGATION The field portion of this study was completed on the site located on Sandy Lake and Denton Tap Road in Coppell, Texas on April 28, 1997. The subsurface soil conditions were explored by advancing and sampling five (5) soil borings. Soil boring B-1 was drilled to a depth of twenty- five(25')feet, soil boring B-2 to a depth of twenty (20')feet, soil boring B-3 to a depth of fifteen (15') feet and borings B-4 and B-5 were drilled to a depth of five (5') feet below existing ground surface. The approximate boring locations are shown on the attached Boring Plan, Plate No. 1. Sample depth,description of soil and soil classification(Based on the Unified Soil Classification System) are presented on the Boring Logs, Plate Nos. 2 and 3 . Keys to terms and symbols used on the boring logs are shown on Plate No. 4. The soil borings were of three-inch diameter. Undisturbed samples of the soils were obtained at two (2) foot intervals continuously to a depth of ten (10) feet, and at five (5) foot intervals thereafter. Samples of the soils were obtained by means of three-inch O.D. shelby tube sampler. All undisturbed samples were extruded mechanically from the shelby tubes in the field, wrapped in aluminum foil, and sealed in plastic bags to prevent moisture loss and disturbance. All of the samples were transported to our geotechnical laboratory for examination, testing and analysis. LABORATORY TESTING All field soil samples from the borings were examined and classified by a soils engineer. Laboratory tests were then performed on selected soil samples in order to evaluate and determine the physical and engineering properties of the foundation soils in accordance with the prescribed ASTM standards. Strength properties of the soils were determined by means of Unconfined Compressive Tests performed on undisturbed samples. GEOSCIENCE ENGINEERING AND TESTING, INC. Malouf Interest,Inc. GET NO.: 97DG1146 May 12,1997 Page 2 The type and number of laboratory tests performed for this study are: DESCRIPTION NO. OF TESTS Hand Penetrometer Test 38 Moisture Content Tests 38 Atterberg Limits 11 Dry Density Test 5 Unconfined Compression Test 5 The tests noted above were performed to establish the index properties and to aid in the proper classification of the subsurface soils. The test results are shown on the boring logs and are presented on Plate Nos. 2 and 3. GENERAL SUBSURFACE CONDITIONS The site is gently sloping and covered with grass. The surface soils were dry and hard at the time of our investigation. The specific subsurface stratigraphy as determined by the field exploration, is shown in detail on the boring logs herein. However, the stratigraphy can be generalized as follows: Depth (FT.) DESCRIPTION 0' - 4' Very Stiff Brown and Tan Clay to Sandy Clay (CH- CL)*. 4' - 10' Soft to Very Stiff Gray and Tan Sandy Clay. (CL). 10' - 25' Firm to Very Stiff Gray and Tan Sandy Clay-Slickensided (CL).. * Classification is in accordance with the Unified Soil Classification System.0 The information in this report summarizes conditions as found on the date the borings were drilled. Free groundwater was encountered in soil borings B-1 and B-2 at a depth of Nine (9') feet and in soil boring B-3 at a depth of fourteen (14') feet during the field drilling operation. Long term monitoring of the groundwater level was beyond the scope of this study. It should be noted that the groundwater table may be expected to fluctuate with environmental variations such as frequency and magnitude of rainfall and at the time of year when construction begins. GEOSCIENCE ENGINEERING AND TESTING, INC. Malouf Interest,Inc. GET NO.: 97DG1146 May 1 2,1997 Page 3 EXPANSIVE CLAY The Atterberg Limit tests indicate that the Liquid Limit of the soils in the upper 8 feet is in the order of 29 to 71 and the Plasticity Index (P.I.) is in the order of 14 to 49. The subsoil would then be described as clays having a low to high shrink/swell potential. UNDERREAMED FOOTINGS Based on the soil conditions revealed by the field soil test borings, the structure at this site can be supported on a foundation system comprised of drilled and underreamed footings bearing at a depth of twelve (12) to thirteen (13) feet below existing grade in the layer of gray and tan sandy clay. The footings may be sized for a net allowable bearing pressure of 2,500 psf for dead load plus sustained live load. The bearing pressure contains a factor of safety of 2.5 and can be increased 25 per cent for total load conditions, whichever is critical. The plinths of underreamed footings should be reinforced with sufficient reinforcing steel to resist the potential tension force induced by swelling soils between the depth of seasonal moisture changes and the final ground surface elevation. Caving of piers may occur during construction of the drilled piers due to the presence of sandy clay and groundwater. In order to minimize the possibility of piers caving during drilled pier construction,the construction contractor should be prepared to use Cased Piers or Straight Sided Shaft Foundations if caving occur. We recommend that the drilling be performed under the supervision of a Geotechnical Engineer. Experience indicates that underreams can be successfully installed, and based on local practice for performing underream drill piers is to utilize 3.0 to 1.0 for underream to shaft ratio. Should caving occur during belling operations, the shaft diameter may have to be increased, thereby, changing the bell to shaft ratio. If the soil conditions warrant the changing of the shaft diameter, the Structural Engineer of record should be informed about any changes because they may require a change in reinforcing steel or bell diameter. Another alternative, would be to change the typical 45 degree angle of the underream to 60 degree. The concrete should be placed in a timely manner after drilling to minimize the potential for caving of the foundation soils. No footings should be poured without the prior approval of the Project Engineer,Architect or Owners Representative. Since the exact size and locations of the footings are not known at this time. A detailed settlement analysis was not authorized, nor performed. It is anticipated that the footings designed using the recommended allowable bearing capacity will experience small settlements that will be well within the tolerable limits for the proposed structure. A detailed settlement analysis can be performed, if desired. GEOSCIENCE ENGINEERING AND TESTING, INC. Malouf Interest, Inc. GET NO.: 97DG1146 May 12,1997 Page 4 A minimum void space of four (4) inches should be provided beneath the grade beams. This void space allows for movement of the expansive soils below the grade beams without distressing the structural system. Structural cardboard void forms are often used to provide this void space. Void Boxes are typically placed under the grade beams to provide this void space, and act as a barrier separating the grade beams from the expansive soils. The purpose for using the void boxes is when the underlying expansive soils swell, the void boxes will then collapse, thus minimizing the uplift loads caused from the expansive soils on the grade beams. These voids may act as a channel for water to travel under a foundation system with poor area drainage, however, if this condition occurs, it may result in the subsequent swelling of the soils and an increase in subsoil moisture loads on the floor slabs. It is our opinion that the determination whether or not to provide voids under the grade beams be made by the owner/builder after both the positive and negative aspects are evaluated. Geoscience Engineering & Testing, Inc. from our experience with these voids, as well as the experiences of other experts, brings us to the conclusion that even though they may be effective in reducing swell pressures on the grade beams, they may provide free water which would be available for absorption by slab support soils. We recommend that the concrete slab of the structure be placed on a minimum of twenty-four (24) inches of non-active type select fill material having a P.I. between 10 and 20 and doweled into the grade beams in order to minimize any possibility of vertical displacement. STRUCTURAL FILL AND SUBGRADE PREPARATION It is recommended that the subgrade and fill material be prepared as follows: (1) The site should be stripped to suitable depths to remove any existing concrete slab, topsoil and miscellaneous fill material. The exposed subgrade surface should then be proof-rolled. All soft or loose soils should be removed and replaced with select fill. (2) The natural subgrade should be scarified to a minimum depth of six (6) inches. The scarified soils should then be recompacted to a minimum of 95 percent of the maximum dry density as determined by the Standard Proctor Density Test (ASTM D-698). The moisture content should range from -1 to + 3% of optimum moisture. (3) Select till used to elevate the grade should consist of a clean sandy clay with a Liquid Limit less than 35 and a Plasticity Index (P.I.)between 10 and 20. (4) The select fill material should be placed in maximum of eight (8) inch loose lifts and compacted to a minimum of 95 percent of the maximum dry density as per ASTM D- 698. The moisture content should be within -1 to +3 % of optimum moisture. GEOSCIENCE ENGINEERING AND TESTING, INC. Malouf Interest, Inc. GET NO.: 97DG 1146 May 12,1997 Page 5 (5) A bedding layer of leveling sand, two (2) inches thick should be placed immediately beneath the floor slab. A vapor barrier consisting of six mil plastic sheeting should be placed over the sand cushion to prevent water migration through the concrete slab. The excavations for the grade beams should be clean and free of any loose materials prior to concrete placement. PAVEMENT RECOMMENDATIONS The near surface soils have a high shrink/swell potential and chemical stabilization will be required to render the subgrade soils inactive. The assumptions utilized in our pavement thickness analysis are summarized on Plate No. 5. The following pavement thicknesses are based on these assumptions and procedures published by the Portland Cement Association and the National Crushed Stone Association. Recommendations for material properties for the paving layers are provided on Plate No. 6. It is estimated that the service life for a properly constructed and maintained pavement will be in order of 20 years. Proper civil design features such as joint design, quantity shoulder support should be incorporated into the plans and specifications. Joints for concrete pavements may be designed using the Texas Department of Highways Item 360.7 (Latest Revision). Periodic maintenance will be required. Parking Lots - Automobile Only (DI-1) Flexible Base Rigid Pavement 1.5" Hot Mix Asphaltic Concrete 5.0" Reinforced Concrete 6.0" Crushed Limestone* 6.0" Lime Stabilized Compacted Subgrade 6.0" Lime Stabilized Compacted Subgrade Parking Lots & Light Duty Access Lanes (DI-2) Flexible Base Rigid Pavement 8.0" Crushed Limestone* 6.0" Reinforced Concrete 2.0" Hot Mix Asphaltic Concrete 6.0" Lime Stabilized Compacted Subgrade 6.0" Lime Stabilized Compacted Subgrade GEOSCIENCE ENGINEERING AND TESTING, INC. Malouf Interest, Inc. GET NO.: 97DG1146 May 12,1997 Page 6 Medium Duty Access Drives (DI-3) Flexible Base Rigid Pavement 3.0" Hot Mix Asphaltic Concrete 6.0" Reinforced Concrete 8.0" Crushed Limestone* 8.0" Lime Stabilized Compacted Subgrade 8.0" Lime Stabilized Compacted Subgrade * Plant mix, hot laid asphaltic base (black base) can be substituted on a ratio of one (1) inch of black base equal to 1.5 inches of crushed limestone. SITE DRAINAGE It is recommended that site drainage be well developed. Surface water should be directed away from the foundation soils (use a minimum slope of 5% within 10 feet of foundation). No ponding of surface water should be allowed near the structure. VEGETATION CONTROL We recommend trees not be planted closer than half the canopy diameter of mature trees from the grade beams, typically a minimum of 20 feet. This will minimize possible foundation settlement caused by the tree root systems. INSPECTION DURING CONSTRUCTION The recommendations are based on the subsoils data in the field exploration and laboratory testing. Due to the geological deposition of the soils in the area, variances may occur between boring locations. Therefore,the footing excavations should be inspected under the supervision of a geotechnical engineer to confirm that the bearing soils are similar to those encountered in our field exploration and that the footing areas have been properly prepared. The geotechnical engineer should be immediately notified should any subsoil conditions be uncovered that will alter the conclusions and recommendations contained in this report. Further investigation and supplemental recommendations may be required if such a condition is encountered. Prior to placement of concrete, the footings should be inspected to monitor that: (1) The footing bears in the proper bearing strata at the depth recommended in this report. (2) The footing shaft is to the proper dimensions and reinforced steel is placed as shown on the structural drawings. GEOSCIENCE ENGINEERING AND TESTING, INC. Malouf Interest, Inc. GET NO.: 97DG1146 May 12,1997 Page 7 (3) The footings are concentric with the shaft and the shaft has been drilled plumb within specified tolerances. (4) Excessive cutting, build up of cutting, and any other soft compressible materials have been removed from the bottom of the excavations. Samples of the subgrade soil and structural fill material should be obtained prior to compaction operations for laboratory moisture/density testing (Proctor Tests). The tests will then provide a basis for evaluating the in-place density requirements during compaction operations. A qualified soil technician should perform sufficient in-place density tests during the filling operations to verify that proper levels of compaction are being attained. GENERAL The information and recommendations contained in this report summarized conditions found at the site specified, on the date that the field exploration and soil borings were drilled. The attached boring logs are a true representation of the soils encountered at the specific boring locations on the date of field drilling and represent the stratigraphy as found during the field exploration and drilling of the subject site. Reasonable variations from the subsurface information presented in this report are assumed. If conditions encountered during construction are significantly different than those presented in this report, GETI should be notified immediately. In addition, the construction process may itself alter site soil conditions. Therefore, experienced geotechnical personnel should observe and document the construction procedures and all conditions encountered. We recommend that the owner retain Geoscience Engineering and Testing, Inc. to provide this service as well as the Construction Materials and Testing and Inspection required during the construction phase of the project. We would welcome the opportunity to discuss our recommendations with you and hope we may have the opportunity to provide any additional studies or services to complete this project. The following illustrations are attached and complete this report. Plate Location Plans 1 Boring Logs 2 and 3 Symbols and Terms Used on Boring Logs 4 Assumptions For Pavement Analysis 5 Pavement Material Recommendations 6 GEOSCIENCE ENGINEERING AND TESTING, INC. Revised April 9, 1998 _ --------- --- --- - i 144 Ceri j<r .iSv: . J (r_; r-'i, I f I 1 > II ; .L r- �� -1 rG B-3 - r_. y i g 1 -- . u . eB-5 ( 11.(7 e B-2 a B-1_ !c c ,____x . J„, _, j __ .,,,..' _ ._„_____, „.._ i-�-T S F r -rte 1-1,11® B-4 T J i = - o ) V 'I-.L1i!_Z_11!1_L i .'J _l 1 III ' I a i1/r__ — . ..___�_ ...__-..-__- ... . .._ 1 _-_s ON TAP Roan s s f i ,.______ ..________ _ , l Approximate Boring LOCATION PLAN Locations Proposed Shopping Center Sandy Lake and Denton Tap Road Coppell, Texas GET NO.: 97DG1146 NOT TO SCALE PLATE NO. 1 GEOSCIENCE ENGINEERING AND TESTING, INC. GEOTECHNICAL&MATERIALS ENGINEERS LOG OF BORING PROJECT NO.: 97DG1146 DRY AUGER: 0-25' DATE OF BORING: 04-28-97 % SHEAR STRENGTH DEP. SOIL BLOW DESCRIPTION OF MOIS- DRY pass (TSF) LIQ- IN PER SAMPLES STRATUM TURE DEN # 0 PENETROMETER -UID P.I. FT. SYMBOL FT % pcf 200 • UNCONFINED LIMIT COMPRESSION B-1 0.5 1.0 1.5 1 Very Stiff Brown and Tan Sandy Clay- 15 0 2 Slickensided 12 0 47 29 3 13 0 4 Very Stiff Brown and Reddish Brown 13 O 35 19 5 Sandy Clay / 20 0 6 Soft to Stiff Gray and Tan Sandy Clay 21 0 42 24 7 8 9 V 20 0 10 — 22 111 11 Finn Dark Gray Sandy Clay- 12 Slickensided 13 14 15 21 98 16 17 18 19 20 0 21 22 22 23 24 25 43 0 DRY AUGER: 0-20' DATE OF BORING: 04-28-97 % SHEAR STRENGTH DEP. SOIL BLOW DESCRIPTION OF MOIS- DRY pass (TSF) LIQ- IN PER SAMPLES STRATUM TURE DEN # 0 PENETROMETER -UID P.I. FT. SYMBOL FT % pcf 200 • UNCONFINED LIMIT COMPRESSION B-2 0.5 1.0 1.5 1 Very Stiff Brown and Tan Sandy Clay 11 0 2 Slickensided 14 0 3 20 0 36 19 4 16 0 5 Stiff to Very Stiff Gray and Tan Sandy 17 47 29 6 Clay 15 0 7 8 9 V 15 O 10 -' 16 111 • 0 11 Very Stiff Reddish-Brown and Light 12 Gray Sandy Clay -Slickensided with 13 Concrete 14 15 32 0 16 17 18 19 20 34 0 PLATE NO.: -2- 1 � �` a., 1 GEOTECHNICAL&MATERIAL ENGINEERS LOG OF BORING PROJECT NO.: 97DG1146 DRY AUGER: 0- 15' DATE OF BORING: 04-28-97 % SHEAR STRENGTH - � DEP. SOIL BLOW DESCRIPTION OF MOIS- DRY pass (TSF) LIQ- IN PER SAMPLES STRATUM TURE DEN # 0 PENETROMETER -UID P.I. FT. SYMBOL FT % pcf 200 • UNCONFINED LIMIT COMPRESSION B-3 0.5 1.0 1.5 i 1 Very Stiff Brown and Tan Clay 18 Q 2 14 71 49 3 Very Stiff Gray Clay with Calcareous 17 4 Nodules 16 113 0 68 46 5 Very Stiff Gray and Tan Silty Clay 15 0 6 7 12 0 8 84 ; 18 9 13 0 10 15 111 • 0 11 12 13 14 15 — 18 _ 0 DRY AUGER: 0-05' DATE OF BORING: 04-28-97 SHEAR STRENGTH - DEP. SOIL BLOW DESCRIPTION OF MOIS- DRY pass (TSF) LIQ- IN PER SAMPLES STRATUM TURE DEN # 0 PENETROMETER -UID ; P.I. FT. SYMBOL FT % pcf 200 -• UNCONFINED LIMIT COMPRESSION B-4 0.5 1.0 1.5 1 Stiff to Very Stiff Brown and Reddish 14 0 29 13 2 Brown Sandy Clay 15 0 3 16 0 4 Very Stiff Dad Gray Clay 21 0 5 23 _ 0 , DRY AUGER: 0-05' DATE OF BORING: 04-28-97 % SHEAR STRENGTH DEP. SOIL BLOW DESCRIPTION OF MOIS- DRY pass (TSF) LIQ- IN PER SAMPLES STRATUM TURE DEN # 0 PENETROMETER -UID P.I. FT. SYMBOL FT % pcf 200 • UNCONFINED LIMIT COMPRESSION B-5 0.5 1.0 1.5 1 Very Stiff Brown and Reddish-Brown Clay 13 0 29 14 2 Very Stiff Dark Gray Clay Slickensided 20 0 64 43 3 with Sandy Pockets 22 0 4 16 0 5 16 0 PLATE NO.: -3- KEY TO SOIL CLASSIFICATION AND SYMBOLS SOIL TYPES o p.0•, Gravel (GW,GP, Clayey Sand(SC) 4:i ::;:,i+:!j Sandy Silt(ML) Pp, �'�� x11 e:`� �•t.a�..t.�..;s Sand(SW,SP) re a• Clayey Silt(ML) ///A (C)or Sandy Clay ;>::::•.;; Silty Sand (SM) 11111111111 Silt(ML) � Clay(CH) CONSISTENCY OF COHESIVE SOILS RELATIVE DENSITY OF COHESIONLESS SOIL Description Shear Strength-KSF Penetration Resistance Description Penetration Resistance Relative De-tsity . % Blows/Ft Blows/Ft Very Soft Less than 0.25 0 - 2 Very Loose 0 -4 0 - 15 Soft 0.25 -0.50 2 -4 Loose 4 - 10 15 -35 Firm 0.50 - 1.00 4 - 8 Medium Dense 10 -30 35 -65 Stiff 1.00 -2.00 8 - 15 Dense 30 -50 65 - 85 VeryStiff 2.00 -4.00 15 • 30 Very Dense > 50 85 -100 Hard Greater than 4.00 >30 SOIL STRUCTURE CALCAREOUS NODULES - Nodules of Calcium Carbonate FERROUS NODULES - Nodules of Ferrous Material SLICKENSIDED - Having inclined planes of weakness that are slick and glossy BLOCKY - Having inclined planes of weakness that are frequent and rectangular in pattern LAMINATED - Composed of thin layers of varying soil type and texture FISSURED - Containing shrinkage cracks frequently filled with fine sand INTERBEDDED - Composed of alternate layers of different soil types ISAMPLE SYMBOLS {-A N Shelby Tube Standard Penetration Auger or Wash No Recovery Sample Test Sample GROUNDWATER a (24 hr)-Water level after drilling (time increment after drilling) I_ -Free water observed during drilling FAILURE DESCRIPTION (COMPRESSION TEST) B-Bulge SLS-Failure surface occuring along slickensided plane S-Shear SAS-Failure surface occuring along or in sand seam M/S-Multiple Shear SS -Failure surface occuring in or along other secondary structure such as calcareous pockets PLATE 4 GEOSCIENCE ENGINEERING AND TESTING, INC. ASSUMPTIONS FOR PAVEMENT ANALYSIS 1.0 Traffic Conditions - (National Crushed Stone Assoc.) 1.01 Parking Lots (DI-1) Light traffic - Few vehicles heavier than cars. No regular use by trucks. Daily EAL = 5 or less 1.02 Parking Lots & Light duty Access Lanes (DI-2) Medium-Light traffic - Maximum of 1,000 vehicles per day, including not more than 10 percent two axle loaded trucks or larger vehicles carrying light loads or empty. Daily EAL = 6 to 20 1.03 Medium Duty Access Drives (DI-3) Medium traffic - Maximum of 3,000 vehicles per day, including not more than 10 percent two axle trucks or 1 percent heavy trucks with three or more axles. Daily EAL = 21 to 75 2.0 Flexible Base Pavement 2.01 Saturated CBR of natural clay subgrade: 3 2.02 CBR of imported clay subgrade: 6 3.0 Rigid Pavement 3.01 Modulus of subgrade reaction: 100 pci (imported clay subgrade) 3.02 Modulus of rupture: 500 psi at 7 days (concrete) PLATE NO. 5 GEOSCIENCE ENGINEERING AND TESTING, INC. PAVEMENT MATERIAL RECOMMENDATIONS 1.0 Limestone Base - Base material shall be composed of crushed limestone meeting the requirements of grade 1 in the Texas Department of Transportation(TexDOT) 1-993 Standard Specifications Item 247. The limestone shall be compacted to a minimum of 95 percent of the maximum density as determined by the Modified moisture/density relation (ASTM D 1557). 2.0 Hot Mix Asphaltic Concrete Surface Course (Class "A") - The asphaltic surface course should be plant mixed, hot laid Type "D": (Fine Graded Surface Course) and meet the requirements specified in TexDOT Item 340. 3.0 Asphalt Stabilized Base - Plant Mix - The asphaltic base should be plant mixed, hot laid and meet the requirements specified in the TexDOT 1993 Standard Specifications Item 345. 4.0 Concrete - The materials and properties of concrete shall meet the applicable requirements in the ACI Manual of Concrete Practice. The concrete shall have a minimum modulus of rupture of 500 psi at 7 days as per ASTM C 293. It is our experience that concrete with a compressive strength of 3,000 psi should meet this criteria. The mixture shall contain 3 to 5 percent entrained air. PLATE NO. 6 GEOSCIENCE ENGINEERING AND TESTING, INC.