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HDR Engineering, Inc. Law Proposal No. 132M9 June 13. 1988 gradation and plasticity tests for evaluation_~.HDR. AFter this evaluation by HDR. we will perform requested aggregate-qual'~ty sample from the aggregate source selected by HD~.testsd°n a representative If~he results of the aggregate quality tests sre suitable, then approximately 1500 pounds of the selected aggregate will be obtained fo~ an RfC trial mix. q]%e RfC laboratory trial mix program will consist of first conducting s 5- point compaction test to determine the optimum moisture content and maximum dry density of the aggregate. As outlined in furnished test procedures, molds will be furnished by HDR. Qradation tests will be made on the compaction test sample before and after compaction to determine breakdown. Second, RCG trial batches will be mixed and test cylinders formed for compressive strength test specimens, As requested, 6 cylinders each for 3 different cement contents of 200, 240 and 280 lbs/cy of dry weight.of the aggregate will be prepared. Type II cement from a designated source will be used. The cylinders will be compacted (using the same p~ocedure as for the a~gregate alone) 5nto 6 by 12 inch plastic molds supported by a special split- metal mold. furnished by HDR. The cylinders will be cured in a high humidity room until conventional compressive strength testing at intervals of 7, 28 and 56 da~s. Third, rapid freeze/thaw tests (gSTM C 666, procedure A) will be conducted on prepared sample prisms. The sample preparation will require construction of a special oversize box with the prisms ssw cut from a sample compacted in the special box. Each specimen will be subjected to ]00 c~dles of rapid alternate freezing and thawing cycles with photographs being taken of each specimen at requested intervals during the testing. Estimated Fee Based on our understanding of the testing requirements, we recommend~a budget allowance of $6500 £or the scope of services described above, including interim reports and a final report. IF additional aggregate sources would have to be identified or additional RCG trial mixes developed that would resfflt in the fees exceeding the figures indicated above, we would obtain your permission before proceeding. Our charges For the exploration, testing and reporting will be computed from actual quantities of work performed and the appropriate uni~ prices shown on the attached Fee Schedule. Schedule We can begin the first phase of the proposed work as soon as we receive your authorization to proceed. We estimate that the exploratlom and testing of aggregate source will require approximately 2 weeks. We assume HDR will be able to select the preferred aggregate within about a week. The aggregate compaction test and compressive strength testing of RfC trial batches will require an additiona~ approximately 2-1/2 months with 7-day results available in about 3 weeks after HDR selects the preferred aggregate source. The freeze/thaw test results will require approximately 3 to 4 months From the time of specimen preparation. ~ 2 ENGIN