Rheology Agent Eases Contractor’s Job

BASF Admixtures Systems has introduced Navitas 33 rheology-controlling admixture (RCA), a new technology the manufacturer notes will improve concrete

BASF Admixtures Systems has introduced Navitas 33 rheology-controlling admixture (RCA), a new technology the manufacturer notes will improve concrete paving in terms of production rate, durability, and final road-surface quality. The product comprises a patent-pending formulation that enables contractors to overcome placement challenges associated with low-slump paving mixtures.

Concrete used in paving applications is purposely designed as a low-slump mix and, therefore, is stiff and difficult to place, says BASF Product Manager Mark Bury. While low-slump concrete ensures that the pavement maintains its high strength and ability to withstand daily traffic and harsh weather conditions, these mixes are difficult to extrude and require harsh vibration for consolidation, potentially causing surface defects that necessitate additional manual labor to rework and finish.

Navitas, the Latin word for ÎenergyÌ, describes the concrete performance for which this admixture reportedly serves as a catalyst: by acting as a lubricant, it adds energy to the mix, product developers assert, improving response to vibration and ultimately enhancing consolidation, extrusion and final surface appearance. Navitas 33 RCA technology lowers the yield stress or force required to initiate concrete flow, without necessarily affecting the viscosity Û an important distinction from viscosity-modifying admixtures that help concrete flow, finish and remain cohesive.

Suitable for use in mainline concrete paving, low-slump concrete, curb and gutter, as well as median barriers, Navitas 33 technology can provide a 20-plus percent increase in production of low-slump extruded concrete placements, the company affirms. Additional manufacturer-cited benefits include optimized mixes, lower costs, minimized edge slump, and enhanced pavement riding surface, besides increased durability and service life. Û www.masterbuilders.com