. Official proceedings . f this particular quarryand the examination showed that the presence of Beidellite, whichis a clayey material, would account for the lack of durability inthis stone. A chemical analysis, or the ordinary physical tests,did not furnish the information that this stone would not be dur-able in service. It has been found necessary for us to refuse approval of twoquarries because the stone is unsound, although these sources ofsupply are within easy shipping distance to Allegheny County. Having made the necessary research to enable the Engineersto prepare satisfactory specifi
. Official proceedings . f this particular quarryand the examination showed that the presence of Beidellite, whichis a clayey material, would account for the lack of durability inthis stone. A chemical analysis, or the ordinary physical tests,did not furnish the information that this stone would not be dur-able in service. It has been found necessary for us to refuse approval of twoquarries because the stone is unsound, although these sources ofsupply are within easy shipping distance to Allegheny County. Having made the necessary research to enable the Engineersto prepare satisfactory specifications for the given project andobtained copies of orders from the Contractor showing that thematerials are to be purchased from approved and capable sourcesof supply the actual inspection of the materials and methods ofconstruction begin. The Resident Engineer in the field is furnished with equip-ment for testing aggregates at the batcher plant, as shown inFigure 3. This work is done by a representative of the Resident. FIG. 3. 147 Engineer, who is located at the batcher plant, and is furthersupervised by a traveling inspector, working under the Construc-tion Bureau and co-operating with the Testing Laboratory. Incase of controversy samples are taken by a representative fromthe Bureau of Tests and Specifications and delivered to the Lab-oratory for complete tests. Wherever possible materials are inspected and tagged at thesource of supply. Steel is stamped at the rolling-mill and in thefabricating shop. Reinforcing bars are inspected at the mill andtagged with seals which indicate to the Engineer in the field thatthe material has been approved. The Resident Engineer also re-ceives copies of all reports so that he has knowledge as to thematerial which has been inspected and approved. Copper bearingsteel is used in all of Allegheny County Bridge Construction onaccount of its rust-resisting quality. Portland Cement is inspected at the Mills and where it isshipped by truck each b
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