ASTM C94/C94M-15a pdf free download.Standard Specification for Ready-Mixed Concrete.
ASTM C94/C94M-15a covers ready-mixed concrete as defined in 3.2.2 (Note 1). Requirements for quality of ready-mixed concrete shall be either as stated in this specification or as ordered by the purchaser. When the purchaser’s requirements, as stated in the order, differ from those in this specification, the purchaser’s requirements shall govern. This specification does not cover the placement, consolidation, curing, or protection of the concrete after delivery to the purchaser.
10. Batching Plant
10.1 Bins with adequate separate compartments shall he provided in the batching plant for tine and for each required sue of coarse aggregate. Each bin compartment shall be designed and operated so as to discharge efficiently and freely. with minimum segregation, into the weighing hopper. Means of control shall be provided so that, as the quantity desired in the weighing hopper is approached. the material shall be shut off with precision. Weighing hoPpers shall be constructed SO as to eliminate accumulations of tare materials and to discharge fully.
10.2 Indicating devices shall be in full view and near enough to be read accurately by the operator while charging the hopper. The operator shall have convenient access to all controls.
10.3 Scales shall be considered accurate if their accuracy is verified through the normally used capacity in accordance with Table 2 and load indicated relative to applied test load is within ±0.15 of the total capacity of the scale or 0.4% of the net applied load, whichever is greater. The minimum quantity and sequence of applied test loads used to verify material scales shall conform to Table 2 and its notes.
II. Nlixcrs and Agitators
11.1 Mixers will be stationary mixers or truck mixers. Agitators will be truck mixers or truck agitators.
11.1.1 Stationary mixers shall be equipped with a metal plate or plates on which are plainly marked the mixing speed of the drum or paddles. and the maximum capacity in terms of the volume of mixed concrete. When used tr the complete mixing of concrete, stationary mixers shall be equipped with an acceptable timing device that will not permit the batch to be discharged until the specified mixing time has elapsed.
11.1.2 Each truck mixer or agitator shall have attached thereto in a iromincilt place a metal plate or plates on which are plainly marked the gross volume of the drum, the capacity of the drum or container in terms of the volume of mixed concrete, and the minimum and maximum mixing speeds of rotation of the drum, blades, or paddles. When the concrete is truck mixed as described in 12.5. or shrink mixed as described in 12.4, the volume of mixed concrete shall not exceed 63 % of the total volume of the drum or container. When the concrete is central mixed as described in 12.3, the volume of concrete in the truck mixer or agitator shall not exceed 80 % of the total volume of the drum or container. Truck mixers and agitators shall be equipped with means to readily verify the number of revolutions of the drum. blades, or paddles.ASTM C94/C94M-15a.