(1) The raw materials used for concrete production are not a single homogeneous body with stable performance. During continuous production, external interference shall be eliminated and attention shall not be distracted;

(2) During normal production, pay attention to the change of concrete slump, master the influence of water content adjustment on slump, have the right to adjust water content and inform the on duty tester;

(3) In case of any mechanical failure, it must be reported for repair in time. If necessary, it shall be shut down concrete mixing plant immediately to avoid causing large losses.