试拌 meaning in English

trial batch
trial mix

The reduced minimum cement contents shall only be used when trial mixes have verified that concrete with a maximum free water / cement ratio not greater than that given for a particular condition can be consistently produced and it is suitable for the conditions of placing and compacting
只有经过试拌证实，可以持续不断地生产出最大水灰比不大于某一特定工况给定值的混凝土，而且这种混凝土适合于摊铺与夯实，在这种情况下，才可以使用这一缩减的最低水泥用量。
Mixture mixing : install and debug the mixing equipment before construction , take the trial mix according to the mixture ratio , and find out the turning on location of every hopper strobe as well as the relation among material flow of every kind , draw up the curve , and if there is adjustment because of factors like material batch , difference of moisture content and so on , it need to be confirmed by the laboratory so as to ensure the mixture ratio of construction meet the design requirement
混合料拌和：施工前首先安装、调试好拌和设备，根据确定的配合比进行试拌，找出各料斗闸门开启位置与各种材料流量的关系，并绘制成曲线，如因材料批次、含水量不同等因素而调整,须由试验室确定，以确保施工配合比符合设计要求。