Grout Pumping and Injection Operations TR 003 The Type HE cement grout mixes are designed from very “thick” mixes, i.e. Water/Binder ratio (W/B) of 0.35 to very “thin” mixes of W/B 2.0 The Type HE cement grouts are summarised below. The sequence of addition of materials to the grout mixer and also the mixing time is very important to make sure the properties of the grout are achieved as per design. The batching sequence or order of addition of materials to the mixer is always as follows: 1. Water – added through a water meter. 2. Liquid additives (i.e. firstly the super-plasticiser and then secondly the Grout-Aid) – generally added manually using graduated jugs/buckets. 3. Cement – generally added manually, in 20kg bags. The example grout mix Batch Card (below) shows the mix type, i.e. Type HE cement, the Water/Binder ratio (W/B) and the material proportions and order in which they are added for several batch sizes. Let us walk through an example: Mix Type HE - W/B 0.7 Batch size of 167 litres So, Step 1 Dial up 92 litres on batch water meter and start the flow. Step 2 Start the mixer running. Step 3 Measure 2.5 litre of SP into a marked jug and add to mixer. Step 4 Measure 27 litres of GroutAid in two buckets and add to mixer. Step 5 Make sure all liquids are in and mixed for at least 30 sec before adding cement. Step 6 Add cement, one bag at a time onto the bag splitter and empty contents into the mixer until the required number of bags has been added, in this case 7 bags.
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