TAC Corporation, in pursuit of happiness of all employees, and pursuing zero subsidence in all Shield construction projects.

TAC Corporation

Air Mortar (FLOW-TAC)

Defying common understanding of mortar everyday, FLOW-TAC, our original in-house developed Air Mortar product is fully strength adjustable and pumpable to more than 2000m under pressurized conditions.

About Air Mortar

Air Mortar is mixed mortar, consisting of foamed bubble combined with raw slurry mortar.
Basically consisting of cement, clay-based fine aggregate, water and foaming agents etc. The strength of the Air Mortar can be fine-tuned to suit a wide range of situations using various additives.


FLOW-TAC Air Mortar developed TAC has dramatically improved clay Air Mortar by using Bentonite. This adaptation has allowed TAC to give the mortar liquidity and stability beyond what was thought possible years ago. The aeration within FLOW-TAC Air Mortar are extremely strong,
・fine enabling a high level of fluidity(Flow value is high)
・a very low level of material bleeding within the mortar pre-setting.
Because of these main features, FLOW-TAC can perfectly fill up annular shield gaps and are able to be pressurized fed to the gap even when there is 2000m or more between the plant and the gap. By utilizing a further additive, TAC-FLOW AID, we are proud to be able to pump and unprecedented 3500m direct from plant to injection site.

● FLOW-TAC(Flow value 300mm)
● Fluidizer addition(Flow value 400mm)
How to use

TAC-FLOW is multi-use: Shield tunnel annular gap grout injection, and void-filling for mountain tunnels, revetments and building foundations.

Example of Combination(per 1 ㎥)
Uniaxial Compressive Strength (28 day strength) Blast Furnace Cement TAC-α TAC-FORM H/th> Water Air Quantity Specific Gravity
0.1〜0.2N/m㎡ 200kg 30kg 0.8kg 522L 40% 0.75
0.5〜1.0N/m㎡ 250kg 30kg 0.8kg 506L 40% 0.79
1.0N/m㎡ 300kg 25kg 0.7kg 541L 35% 0.87
1.5N/m㎡ 350kg 25kg 0.7kg 525L 35% 0.90
2.0N/m㎡ 400kg 25kg 0.4kg 658L 20% 1.08

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