Page 67 - PH_Masonry_Final_Ver 1_July 2020

F1: Mortar Mixing

Mix Proportions

Before mortar can be mixed, the ingredients have to be measured in their correct proportions.

The ingredients can be measured by:

 Volume - volume mixing can be carried out by hand or by machine.

 Weight - weight mixing can only be carried out by machine.

Mixing by Volume

Volume mixing by hand using a bucket: A bucket is used to measure the materials.

Volume mixing by hand using a gauge box: A gauge box is used to measure the materials.

Volume/weight conversions:

Cement: 1 cubic meter = 1.4 tons
Sand: 1 cubic meter = 1.7 tons

Lime: 1 cubic meter = 0.7 tons

Mixing by Weight

Traditional weight batching

 By using a weight batch mixer, the weight of the aggregate is recorded as it is shovelled into
the hopper.

 The materials can be loaded into the hopper while the previously batched materials are being

mixed. The weight of materials can be read on a dial by the operator who controls the weight.

 Water is added in liters (1litre weighing 1kg)

Dry-Silo Mortar System
 The modern equivalent of the traditional weight batching mixer is the dry-silo mortar system

that is becoming very popular. The system involves the delivery of a large stand-alone silo
that is charged with the correctly constituted mix materials in a dry state.

 The correct amount of water for a mix is automatically measured and added each time by a
trained operator.

Specification

Mixing time : It depends on whether the mixing is done by hand or machine

 Machine mixing: This should be between two and three minutes.

 Hand mixing: - This should take as long as required to ensure that all the particles have
been completely integrated together.

Participant Handbook : Masonry 67