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Alliance Residence October 18,2016 J.N.: 2530.00 Page 19 Special jointing detail should be provided in areas of block-outs, notches, or other irregularities to avoid cracking at points of high stress. Subgrade soils below flatwork should be thoroughly moistened to a moisture content of at least 120 percent of the optimum moisture content to a depth of 12 inches. Moistening should be accomplished by lightly spraying the area over a period of a few days just prior to pouring concrete. The geotechnical consultant should observe and verify the density and moisture content of subgrade soils prior to pouring concrete to verify the recommended pre-moistening recommendations have been met. Drainage from flatwork areas should be directed to local area drains or other appropriate collection devices designed to carry runoff water to the street or other approved drainage structures. Flatwork should provide a minimum slope of 1 % away from structures. 6.6 CONCRETE MIX DESIGN Results of laboratory tests on soluble sulfate content of near surface on-site soils are summarized in Table 6.4. According to these results, the potential for corrosion by sulfate reaches up to very severe. We recommend following the procedures provided in ACI 318, Section 4.3, Table 4.3.1 for Exposure Class S3 unless more strict requirements are made by the structural engineer. Upon completion of rough grading, an evaluation of as-graded conditions and further laboratory testing should be completed for the site to confirm or modify the recommendations provided in this section. TABLE 6.4 Summary of Lab Test Results on Soluble Sulfate Content Source Boring Sulfate Content (%)Sulfate Exposure Southern California B-1 0.061 Negligible Geotechnical (2015)B-5 1.380 Severe B-3 1.4 Severe Group Delta B-7 1.6 Severe Consultants (2016)B-9 2.15 Very Severe B-10 2.45 Very Severe 6.7 PRELIMINARY PAVEMENT DESIGN 6.7.1 Preliminary Pavement Structural Sections One resistance (R-value) test performed by GDC resulted in R-value of 34. This test was performed on a silty sand (SM) specimen that may not be representative of the near-surface soil that is generally composed o f sandy and silty clay. Based on this material description, an R-Value of 10 is used for preliminary pavement design. The traffic volume is represented by three values of traffic index: TI==5.5, TI=6.0, and TI=6.5. The resulting preliminary pavement sections are provided in the following table. The sections provided herein are for planning purposes only and should be re- evaluated subsequent to site grading. Final pavement sections should be based on actual R-value testing of in-place soils and analysis of anticipated traffic. ALBUS-KEEFE & ASSOCIATES, INC.