Concrete Products covers the issues that attract producers of ready mixed and manufactured concrete focusing on equipment and material technology, market development and management topics.
Issue link: http://concrete.epubxp.com/i/442865
68 • January 2015 www.concreteproducts.com FEATURE BY DON MARSH PRODUCTION ECONOMY Dry microspheres have been used successfully in Europe for years in niche concrete applications, notes BASF Admixture Systems, but the cost of delivery has hampered widespread adoption. With a footprint approximating a pickup truck bed, the company's point-of-use MasterSphere FT 300 manufacturing and raw material feed make it eco- nomically feasible to use microsphere technology for freeze-thaw durability in lieu of conventional air-entrained concrete. BASF Admixture Systems began aggressive freeze-thaw testing in early 2014 on concrete beams, cast with MasterSphere FT300-dosed mixes, along the Treat Island, Maine, shore—an environment where specimens are assured constant wetting and drying due to prolific Bay of Fundy tides. Additional testing has continued through concrete producers participating in beta phase microsphere manufactur- ing and specimen preparation, along with transpor- tation agencies that have hosted BASF Admixtures Systems demonstrations in New York, Minnesota, Illinois, Utah and Alberta. Anchoring market acceptance activities, the demonstrations have seen sample MasterSphere FT 300 production in a containerized lab, and prepara- tion of test specimens affording freeze-thaw dura- bility measurement against hosting agencies' con- trol samples—beams, cylinders and slabs cast with conventional air-entraining agents. BASF Admix- ture Systems is compiling performance data from the field and preparing to resume state and province demonstrations in the spring, leading to the Master- Sphere FT 300 commercial debut later in the year. — www.master-builders-solutions.basf.us BASF Admixture Systems Petrographer Jacki Atienza deploys a digital microscope with 3-D capability to illustrate a MasterSphere FT 300 concrete specimen; with the diameter approximately that of an average human hair, the microsphere shown in the close up view (below) is magnifed 1,500 times. The product is dispersed in a liquid admixture solution (bottom) for ease of dispensing and mixing concrete. PHOTOS, MICROGRAPH: BASF ADMIXTURE SYSTEMS In conventional air-entrained concrete, scaling or internal deterioration can be the result of an in- adequate air void system caused by factors such as materials, production procedures, and construction practices; none impact the freeze-thaw durability of MasterSphere FT 300 concrete.