Commander, U.S. Army Engineer Waterways Experiment Station, Corps of Engineers, 3909 Halls Ferry Road, Vicksburg, MS 39180

66 -- BT RHEOM CONCRETE FLOWMETER FOR TEST AND EVALUATION DUE 082997 POC Mallorie O. Irwin, Purchasing Agent, (601)634-4116 WEB: Contract Division Homepage, http://www.wes.army.mil/contract.htm. E-MAIL: Mallorie Irwin W81EWF7218909, irwin@exl.wes.army.mil. The USAE Waterways Experiment Station (WES) proposes to award a purchase order to Laboratoire Central des Ponts et Chaussees (LCPC), Paris, France, under authority of 10 U.S.C. 2304(c)(1) for the procurement of two (2) BT RHEOM Concrete Flowmeters for test and evaluation purposes. This is a notice of intent to procure on a sole source basis. WES is in an agreement with the Federal Highway Administration to develop a protocol for field measurement to determine plastic concrete rheology. The test will be designed to measure shear stresses at a minimum of two shear rates to define rheological properties of portland cement concrete. Concrete of interest will have a maximum nominal aggregate size of 1.5 in. and have slumps ranging from 2-in. and lower to self leveling concrete. The testing will be strictly designed for routine field test application. The test method shall be simple and easily performed by a single individual using a field portable measuring device. This rheology device must be portable so that one person, without the special aid or additional help, can load, unload, install, uninstall, and operate the equipment. The amount of material used for testing shall be approximately 0.2 dubic feet and not exceed 0.4 cubic feet (approximately 60 lbs of concrete.) The apparatus shall be capable of applying shear to the sample at a steady state in a range of shear rates between 2 and 10s(-1) using a loading program to control parameer vx time, have calibration capabilities, and be able to convert measurements to fundamental units of rheology. Its configuration should use a proven rheological method such as rotating disc, prevent slippage between active components such as between the disc and the concrete and be corrosion resistant to environments associated with production of portland cement concrete. The apparatus is capable of imparting known vibration to the concrete prior and during rheological measurements. As part of this work, the WES intends to purchase two BT RHEOM Concrete Flowmeters for test andevaluation. Each rheometer is able to determine the rheological property of fresh portland cement concrete containing 25 mm maximum nominal size aggregate with or without vibration for concrete having slumps of 10 cm or greater. With vibration, rheological measurements can be made on concrete with slumps down to 5 cm. The apparatus is configured such that one can operate it in the US using standard electrical resources and consists of a motor unit and tank which form the structure of the flowmeter, electronic acquisition card and PC, ISA interface, 100 seals, and specific ADRHEO and BDRHEO software for calculation of rheological values i.e. shear yield stress (Pa) and plastic viscosity (Pa.s). Mass of the test apparatus is 28.5 kg and the mass of the control device is 8.4 kg. The foregoing described BT RHEOM Concrete Flowmeter will be tested and evaluated for the sponsor, the Federal Highway Administration. No other sources will be sought. There is no solicitation document. Any inquiries should be received within fifteen days from the date of publication. (0226)

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