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Aggregates and Water
How Aggregate Moisture Affects Concrete Mixes
Description
Aggregate moisture affects concrete mixing by changing how much water must be added to the batch. Moisture content is the water coating the outside of aggregate that is in a saturated and surface-dry state. The total water in moist aggregate includes both moisture content and water absorption.
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Transcript
集料的含水率是指集料表面在饱和面干状态下所含的多余水分。
通过浮力计测试进行测量。
对于潮湿的集料,其吸水率与含水率之和即为其总含水量。
通过实验室中的烘箱或安装在集料储存仓中的电子设备来测定。
当砂堆暴露于雨水和阳光下时,砂粒表面可能会在砂堆内部保留游离水分。
这种自由水分会使相邻的砂粒彼此分离,从而增加一定质量砂的体积,这一现象称为砂的膨胀。
砂的蓬松化导致一定体积内砂的质量减小。
在混凝土称重配料过程中,需额外添加砂子以补偿因水分引起的体积增加,同时从拌合物中扣除相应量的水,以抵消砂子中已含的水分。
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