able to view by small segments the full-scale reproduction of the entire surface of a bore hole from top to bottom. Entrained air and improved fine aggregate grading control for concrete. Investigations have shown that use of a small controlled quantity of entrained air in concrete improves workability, reduces the required amount of mixing water, and improves the resistance of the hardened concrete to attack by weathering agencies. The improvement in workability and reduction in required amount of mixing water has made it possible to appreciably reduce the amount of cement necessary for strength and placeability in mass concrete for gravity-type dams and for concrete for other hydraulic structures. In order to obtain maximum benefits from use of entrained air in concrete, the aggregates used, particularly the fine aggregate, must be properly graded and the grading closely controlled. Investigations have also been made as a basis for determining desirable gradings for fine aggregate, and specifications have been written to insure proper control of grading. Due to the use of entrained air in concrete with properly graded and controlled aggregates, it has been possible to effect a reduction in cement of between onefourth bag and one-half bag per yard of concrete. Approximately 25 million cubic yards of concrete have been placed in this manner, with a saving of over $5 million. Reduced cost due to longer life and lower maintenance cost on structures built using entrained air concrete also are difficult to evaluate, but may easily equal the saving in construction cost due to the reduction in quantity of cement used. Absorptive form lining. Prior to the beginning of general use of entrained air in concrete, attempts were made to improve surface quality by utilizing absorptive material as a form lining to impart a dense "casehardened" effect to the surface. Investigations into the value of absorptive form lining with entrained air concrete were conducted and as a result, the use of absorptive form lining was discontinued on four projects then under construction with a saving of about $400,000. FISCAL TABLES The funds with which the works for the maintenance and improvement of rivers and harbors and flood control were prosecuted during the fiscal year were derived from unexpended balances of prior appropriations and from the following appropriation acts, and by transfer from other departments: Payments to States, Flood Control Act, 28 June 1938.... 28 June 1938, as amended. 988,884.52 The total actually expended under the direction of the Chief of Engineers in connection with the maintenance and improvement of rivers and harbors, flood control, and other miscellaneous works during the fiscal year ended 30 June 1954, follows: MISCELLANEOUS APPROPRIATIONS: 527,448,308.52 4 Mar. 1931.. 6,201,839.18 913,799.83 U. S. Section, St. Lawrence River Joint Board 11 May 1954. 254.02 of Engineers, Corps of Engineers, Civil, Payments to States, Flood Control Act, 28 June 1938... 988,884.52 Working Fund, Army Engineers, Civil, No Year (Various Projects). Working Fund, Army Engineers, Civil, 1948-52. Working Fund, Army Engineers, Civil, 1953. Working Fund, Army Engineers, Civil (Special Fund), 1953-54. Working Fund, Army Engineers, Civil, 1954. Working Fund, Army Engineers, Civil (Trust Military Assistance Near East and Africa, Permanent Fund (Allocated $2,546,524.21 121,500.00 192,306.57 39,675.54 1,081,157.81 12,370.98 4,832.21 473,087.03 Soldiers Home 2,029,476.30 The funds transferred from other departments as working funds are summarized in the following table. Consolidated Working Fund, Army Engineers, Various... 6,284.19 Working Fund to Corps of Engineers, Civil.) 41,600.00 Total working funds 3,969,628.15 $6,723,405.27 Trust funds (contribution and advances) under various acts are summarized below: 8,080,905.27 The following amounts have been advanced by local interests for river and harbor improvements under the provisions of section 11, River and Harbor Act, 3 March 1925, and for flood-control works under the provisions of the act of 15 October 1940, and are returnable to the same interests when necessary Government funds are available. |