AASHTO T162-16 pdf free download
AASHTO T162-16 pdf free download.Mechanical Mixing of H ydraulic Cement Pastes and Mortars of Plastic Consistency.
1. SCOPE
1.1. This method covers the mechanical mixing of hydraulic cement pastes and mortars of plastic consistency.
1 .2. The values stated in SI units are to be regarded as the standard.
1 .3. This standard does not purport to address all of the safety concerns, if ani associated with its use. It is the responsihili oft/ic user of this standard to establish appropriate safei’v and hea It/i practices and determine (lie applicability of regulatory limitations prior to use.
2. REFERENCED DOCUMENTS
2.1. d4ASHTO Standard:
• M 201, Mixing Rooms, Moist Cabinets, Moist Rooms, and Water Storage Tanks Used in the Testing of Hydraulic Cements and Concretes
2.2. ASTM Standard:
• C778, Standard Specification for Standard Sand
3. SIGNIFICANCE AND USE
3.1. This method is intended for use in the mechanical mixing of pastes and mortars for the testing of hydraulic cements.
4. APPARATUS
4.1. Mixer—The mixer shall be an electrically driven mechanical mixer of the epicyclic type, which imparts both a planetary and a revolving motion to the mixer paddle. The mixer shall have a minimum of two speeds, controlled by definite mechanical means. (Rheostat adjustment of speed will not be acceptable.) The first, or slow, speed shall revolve the paddle at a rate of 140 ± 5 r/min, with a planetary motion of approximately 62 r/min. The second speed shall revolve the paddle at a rate of 285 ± 10 r/min, with a planetary motion of approximately 125 r/min. The electric motor shall be at least 124 W (/6 hp). The mixer shall be equipped with a screw that is an integral part of the mixer or a clearance adjustment bracket as shown in Figure 1 (sec Note 1), which shall be used to maintain the clearance between the lower end of the paddle and the bottom of the bowl not greater than 2.5 mm, but not less than 0.8 mm (see Note 2) when the bowl is in the mixing position.Note 1- When the bracket is in the proper position beneath the motor housing, the lugs are to the front and facing upward, and the heads of the adjustment screws are to the rear and facing downward in the path of the sliding frame that holds the bowl. It is intended that the bracket be fastened at the front housing connection by inserting replacement screws of an appropriate size upward through the opening in each lug and into the existing threaded holes in the bottom of the motor housing. The original stops for the sliding frame are to be filed down if they prevent the frame from coming in contact with the adjustment screws. Note 2- This is the approximate diameter of a grain of 20- -30 sand as described in ASTM C778. 4.2. Paddle- -The paddle shall be readily removable, shall be made of stainless steel, and shall conform to the basic design shown in Figure 2. The dimensions of the paddle shall be such that when in the mixing position, the paddle outline conforms to the contour of the bowl used with the mixer, and the clearance between corresponding points on the edge of the paddle and the side of the bowl in the position of closest approach shall be approximately 4.0 mm, but not less than 0.8 mm.AASHTO T162-16 pdf download.
