Slump flow monitoring

摘要

Method and system for monitoring slump flow of hydratable cementitious material such as wet concrete in a rotating mixing drum. Whereas prior art methods use a single value of the hydraulic pressure for turning the drum (such as the average value) and correlating with slump values using the vertical drop measurements of the standard slump test (e.g. ASTM C 143-05), the present invention involves analysis of values corresponding to slump flow of concrete samples, preferably having slump flow values of 16-36 inches when measured using standard slump flow tests (e.g., ASTM C1611-05).

主权项

1. A method for monitoring concrete, comprising:
(A) rotating a mixing drum mounted on a delivery truck and having an inner drum surface upon which at least one mixing blade is attached such that said at least one mixing blade rotates with said mixing drum, said mixing drum containing concrete therein and being rotatable by a hydraulic system having charge and discharge ports, the delivery truck further having a first hydraulic pressure sensor on said charge port and a second hydraulic pressure sensor on said discharge port; (B) providing a sequence of values calculated as the difference between the charge and discharge pressure as sensed by said first and second hydraulic pressure sensors on said charge and discharge ports of the hydraulic system to rotate said mixing drum containing concrete at one particular speed V1 and calculating an average value based on said sequence of values; (C) comparing said calculated average value to a set of average values at speed V1 previously stored in computer memory storage location, said previously stored set containing values obtained from concrete having predetermined slump flows at various slump flows within a range of 16 inches to 36 inches as determined by measuring horizontal spread of concrete released from a slump cone; and (D) providing an indication of slump flow corresponding to said calculated average value provided in (B); adjusting the slump flow of said concrete in said mixing drum based on comparing said calculated average value to a set of average values previously stored in computer memory storage location; or performing a combination thereof.