Ultra High Performance Cementitious (UHPC) Materials for Repair Applications

NaX UHPC grout

NauticAWT has developed and are manufacturing UHPC materials, including the NaX™ Q140 and NaX™ B190 products, primarily used for subsea strengthening and repair applications.

The UHPC materials are commonly used for infill of tubular joints and braces and unstressed grouted subsea clamps where a very high compressive strength and E-modulus is needed.

The NaX™ Premix system is composed of selected blends of silica sand and special high performance aggregates with an optimised grading. In combination with NauticAWT’s advance binder technology based on nanotechnology the NaX™ products has obtained unique performance qualities.

The unique material technology gives ultra high dense materials with results in materials with extreme low permeability and thereby high resistance to ingress of chlorides, sulphate and other types of chemical degradation. NaX™ materials dense nanostructure further more results into a series of unique mechanical behaviour such as extreme high compressive and flexural strength, up to 10 times stronger than normal concrete, and an E-modulus of more than 60 GPa.

In general cementitious materials shrink over time with can result in reduced or no adhesion to a steel structure. In order to overcome this issue all NaX™ materials has been shrinkages compensated and has a long-time unique high adhesion to steel. This is essential in connection to structural repair solutions.

For offshore installations, it is very important to have a material that can be pumped over long distances in long period of time at both high and low temperature. At the same time it is important to get high early strength even at low temperature in order to save valuable offshore time.

NaX™ Premix series has the parameters and a product can be selected to fulfil the actual needed offshore demands to a grout material.

Performance Data NaX™ Q140 NaX™B190
Compressive Strength, MPa 140  190
Static Modulus of Elasticity, GPa 55  70
Tensile Strength, MPa 9  12
Flexual Strength, MPa 20  25
Density, kg/m3 2500  2750
Poisson’s Ratio 0.19  0.19
Flow Consistency, mm 260  260
Chloride Penetration Class Very Low  Very Low
Shrinkage, 0/00 0.1  0.1