Material manufacturers and processors continue to deliver a flourish of products for cast-in-place concrete applications, plus high slump and zero slump precast. Here, Concrete Products examines innovations in cementitious materials and admixtures, plus manufacturers' management moves aimed at capitalizing on opportunities in today's strong concrete business climate.

Axim Concrete Technologies The manufacturer has introduced four liquid admixtures for zero slump concrete. Each agent has been tested and commercialized by European sister Italcementi Group operations.

The Intrapel NS product is formulated as a water repellent and efflorescence control agent in concrete block and pavers. Along with it are three products under the Vibroplex heading: BF, a plasticizing, texture-enhancing agent for concrete pipe and masonry; BF3, a product formulated to increase strength development of block and paver units, while reducing curing time requirements; and NC, a nonchloride agent aimed at accelerating setting time and increasing early strengths of block and paver units. The BF3 is based on Axim's proprietary Superflux 2000PC polyacrylate polymer technology.

Grace Construction Products The company has introduced an admixture aimed at zero slump landscaping products and concrete roof tiles, while also launching a dedicated paver unit in its Masonry Products Group.

Trysta Freeze/Thaw Durability Enhancing Admixture is earmarked for producers of concrete segmental retaining walls, paving stones, roof tiles and other dry-cast concrete units exposed to repeated freezing and thawing cycles. The admixture improves the resistance of low slump concrete to the detrimental effects of freezing and thawing, even in the presence of deicing salts, product developers note. They add that the proprietary agent can be used to maximize the efficiency of manufactured concrete by allowing economic savings, while improving units' freeze/thaw durability.

When water freezes it expands by approximately 9 percent. The friction-reducing polymers and surfactants contained in the admixture entrain micron-sized air bubbles that act as escape boundaries for unfrozen water pushed by the expansive ice front during a freezing cycle. Accommodating the transitional volume change without significantly stressing the concrete microstructure protects the integrity of dry-cast concrete products.

Trysta admixture enhances cement dispersion in dry-cast concrete mixtures, which improves cement utilization. Several economic benefits including effective cement and pigment reduction, greater durability, decreased overall life-cycle costs, and reduced product liability have been proven using this product, product developers report. Desired physical characteristics are achieved without overdesigning the mix, they add.

The Trysta development occurs on the heels of Grace's introduction of two new products to improve the quality and appearance of pavers: Quantec, a color enhancing admixture; and Decapave Ultra, for higher strength development. The former product reacts chemically with hydrating cement to keep efflorescence from blooming, and has a neutral effect on concrete properties such as compressive strength and freeze/thaw durability, while being compatible with most other admixtures. Decapave Ultra can be used to increase the compressive strength of paver units, thereby offering producers an opportunity to optimize cement and pigments, Grace reports.

Paver unit. Shortly after the Trysta roll out, Grace officials announced formation of a new organization within their Masonry Products Group dedicated to supporting the rapidly growing interlocking concrete paver segment (note "A code of their own," Concrete Products, June 1999, page 35.)

"We are bringing technical expertise and research and development focus to the paver industry," explains Masonry Products Group's Jeremy Gray, general manager. The new unit will be staffed by three paver sales specialists, one technical service field specialist and a technical services lab specialist based in the company's Cambridge, Mass., cement, concrete and masonry research and development lab. In addition, the manufacturer has named Randy Welch sales manager for the North American paver team, with special focus on the Decapave Ultra and PVR (efflorescence control), Quantec, Terapave 200 (efflorescence control) and Trysta agents.

Master Builders Inc. While product development efforts that include extension of the company's Glenium polymer technology for admixtures proceed, details of the SKW-MBT Construction Chemicals Group structure and the operating company SKW-MBT Management Inc. were recently reported by Dieter Poech, member of the Board of Management of Germany's SKW Trostberg, and Reini Rutz, president and CEO of SKW-MBT Management. Through internal growth and strategic acquisitions, the SKW-MBT Construction Chemicals Group of SKW Trostberg AG has grown to represent the largest supplier of construction chemicals in the marketplace. In 1997 SKW Trostberg AG, which already owned ChemRex Inc., acquired Master Builders Inc. In March 1999, SKW added to its portfolio Harris Specialty Chemicals.

SKW-MBT Construction Chemicals is now home to the products and resources of several widely recognized players-namely, ChemRex, Master Builders, Watson Bowman Acme, Senergy and ORD Products-and markets such brands as Sonneborn, Thoro, ThoRoc, Ucrete, Hydrozo, Radiance, Wabo, Emaco, Masterflow, Polyheed, Pozzolith, and Rheobuild. In September of last year, SKW rearranged the product offerings of the companies, consolidating products sold through similar channels.

The recent presentation detailed the structure and strategy of SKW-MBT Management, a new legal entity that was formed at the beginning of this year to manage and coordinate the activities of all of the companies and brands in North and Latin America.

"SKW-MBT Management Inc. now has significant purchasing power, and we have streamlined many operations and provided increased services for all of the companies," explained Rutz. "While the companies within the SKW-MBT family go to market through different channels of distribution and often sell to different customer groups, all of these companies are under the SKW-MBT umbrella."

SKW-MBT Management spans:

Chemrex. Operates in Commercial Construction, Industrial and Energy Management divisions. Commercial Construction sells to the construction distributor. All of the products from ChemRex, the former Harris Specialty Chemicals and Master Builders that were sold through distribution are now offered through Commercial Construction.

Master Builders. offers the widest range of chemical admixtures available from a single source as well as equipment for concrete mixing and spraying through the Allentown Equipment Division, company officials note. Master Builders serves ready mixed concrete, precast, block and pipe producers, as well as paving and underground contractors with admixtures, construction solutions and equipment for concrete projects. Master Builders will draw on its worldwide organization's chemical expertise to expand product and technology offerings.

Watson Bowman Acme. Develops expansion joint systems for bridge, building and parking applications.

Selby/Ucrete Flooring. Provides a diverse system of polymer flooring solutions for maintenance, restoration and new construction within industrial and commercial market segments.

Senergy. Manufactures Exterior Insulation and Finish Systems (EIFS) for both residential and commercial buildings, in new construction and retrofit.

SKW Trostberg AG is a publicly quoted specialty chemicals company with 14,000 worldwide employees. SKW Trostberg is organized into four Divisions: Nature Products, Chemicals, Performance Chemicals and Construction Chemicals. The worldwide Construction Chemicals Division consists of 80 companies in 55 countries. With a global workforce of 6,500 employees, the Division achieved 1999 sales of US $1.3 billion and contributed 44 percent of the total SKW group sales of US $3.25 billion.

The manufacturing activities of all the companies have been combined, creating the largest network of plants and warehouses in the construction chemicals industry in the Americas. From 34 plants, this year the company expects to produce in excess of 50 million gallons of admixtures and 250,000 tons of powders, liquids and coatings. These products will be supplied to 40 different distribution centers and warehouses located across the Americas.

The Research and Development capabilities of the SKW-MBT Construction Chemicals Group center on product development and applied research relative to admixture chemistries, cementitious mortars, reactive resins, nonreactive resins, polyurethanes, energy management, mechanical joints and equipment. TwoResearch Centers-in Cleveland, Ohio, and Shakopee, Minn.-employ more than 100 scientists, chemists, engineers and technicians who share information and ideas in an ongoing quest to develop solutions to tomorrow's construction challenges.

Sika Corp. After piloting its ViscoCrete technology with a group of producers that included Oldcastle Precast (Concrete Products, October 1998), Sika Corp. is promoting the admixture for both precast and cast-in-place applications. When included with appropriate combinations of aggregates, the ViscoCrete agent yields a self-placing mix.

The product is based on a proprietary polycarboxylate formulation - one of a handful now being applied globally to create third generation water reducers. Since ViscoCrete's introduction to North America three years ago, the company has added to its polycarboxylate family Sikament 2000, a low dosage, high-range water reducer; and Sikament MP, a mid-range water reducer.

Cortec Corp. The company has introduced MCI 2007-CorrCrete combining a corrosion inhibitor for steel reinforcement and superplasticizer for mix flowability to extend the life of high-strength concrete structures. A free-flowing nonviscous liquid for easy blending, the admixture is water-based, organic and environmentally safe to use at the ready-mix plant and in the field, the company notes.

As a superplasticizer, MCI 2007 improves the flowability of concrete mixtures that have lower water-to-cement ratios. It positively affects the mechanical properties of the concrete, improving compressive and flexural strengths, product developers report. The admixture can be used in all reinforced, precast/prestressed, post-tensioned or marine concrete structures. Additionally, the company notes that other steel-reinforced, high-strength structures that are exposed to corrosive environments are especially suited to this product.

MCI 2007 protects concrete from the explosive power of corrosion in steel-reinforced concrete by forming a thin protective coating on the steel reinforcement, wire mesh, carbon steel, galvanized steel, and other embedded metals. It reportedly provides a powerful system of secondary protection to precoated rebar. When the rebar coating chips off or cracks from excessive flexing, MCI 2007 migrates to the exposed areas to thwart corrosion.

Effective for anodic and cathodic areas, MCI 2007 protects against the harmful effects of corrosion even in the densest concrete, product developers note. The agent protects against corrosion brought on by carbonation, de-icing salts, atmospheric attack, and coastal areas' salt water environment.

Boral Material Technologies, Inc. Company reports introduction of BCN corrosion inhibitor, which protects steel reinforcement and extends the service life of steel in concrete, thus minimizing life cycle costs. The product is a calcium nitrite admixture formulated to improve the integrity of the passivating oxide layer, which typically protects reinforcing steel in a concrete environment by eliminating the defects in the oxide layer. The protective barrier increases the chloride threshold for corrosion initiation at the steel surface. The protective barrier's integrity hinges on the nitrite to chloride concentrations ratio.

Independent studies and research projects conducted with a 30 percent aqueous solution of calcium nitrite have determined its effectiveness for preventing steel corrosion in concrete. BCN consists of that same 30 percent calcium nitrite compound, Boral reports. A project document will specify the dosage rate of company's corrosion inhibitor to be mixed in concrete. The company's Technology Group can also assist with dosage recommendations based upon the anticipated chloride ion content of the concrete throughout the life of the structure.

New York-based Routledge has published for North America the third edition of Chemical Admixtures for Concrete. Authors Roger Rixom and Noel Mailvaganam examine market trends and supplier consolidation since 1986, when the second edition was published, along with:

* Current references and standards in all chapters, plus a new chapter on high range water reducers with emphasis on the acrylic polymer-based agents behind third generation superplasticizers.

* A new section on miscellaneous products, including shotcrete admixtures, corrosion inhibitors, and agents for recycling wash water and returned mixes.

* An expanded chapter on applications, including a section on troubleshooting.

Chemical Admixtures for Concrete surveys current work and thinking, the authors note, and contains the latest understanding of the complex process of admixture-cement interactions and techniques that improve concrete performance.

France's La Rochette Venizel reports development of Novibond, a lignin-based plasticizer for water reduction in concrete or mortar. Product developers note that the agent - packaged as a concentrate or water-soluble powder - improves workability, plasticity, compressive strength and frost resistance, plus rheological properties.

Novibond acts as a dispersing agent, the manufacturer notes, and can help prevent the segregating or balling process common with certain types of cement. Owing to its macro-molecular structure, Novibond can also create interactions between the particles of the materials employed, with the effect of increasing plasticity or reducing the amount of water required for the same level of plasticity, and with a large drop in bleeding. Because of the reduced water requirements, the resulting concrete exhibits greater density, uniformity, compressive strength and durability. - French Technology Press Office

Holnam Inc. The company recently completed a major overhaul of its Chicago Skyway slag processing operation. Acquired from Koch Minerals in 1996, the facility now has 600,000+ tons of production capacity for GranCem, a proprietary ground granulated blast-furnace slag cementitious material. Through special drying and grinding methods, the operation converts slag from the nearby U.S. Steel Gary Works plant to a concrete binding agent with performance and architectural benefits.

The Chicago plant completion followed Holnam's late 1999 unveiling of a plan for a similar facility linked to a U.S. Steel plant in Fairfield, Ala. The two properties join sister operations in South Carolina, West Virginia and Minnesota, which easily position Holnam as the largest GGBF slag cement source in the country.

"These facilities provide an alternative to the growing reliance on imported portland cement to meet the market's long-term infrastructure needs," notes Holnam Mineral Components Division Vice President and General Manager Randy Dunlap. GranCem-bearing mixes cure to a brighter, whiter color than typical portland cement concrete, offering aesthetic advantages in a variety of highway, structural and dry slump (pipe and block) applications, he adds.

Lafarge Corp. The company has entered into an agreement with Isplat Inland Inc. to manage up to 1 million tons of blast-furnace slag annually. Terms call for Reston, Va.-based Lafarge to invest up to $27 million to install slag processing equipment adjacent to the Number 7 iron blast furnace at Ispat Inland's East Chicago, Ind., steel plant.

Scheduled to come on line in the spring of 2001, the facility will include Lafarge's proprietary processing technology for slag exiting the blast furnace. Processed slag exhibits cement-like properties and is being used increasingly in high performance concrete mixes and concrete road pavements, company officials note.

Lafarge plans to sell the processed slag into several core market segments, including paving, ready mixed, and as a lightweight aggregate for manufactured-concrete producers. With an extensive cement distribution network, Lafarge will be able to supply the new product throughout the Great Lakes and Mississippi River basin.

"This is a very cost effective investment," notes Lafarge President and CEO John Piecuch. "We will be able to produce a significant amount of high quality, cementitious material at a far lower capital cost than if we were to build new cement capacity. Also, we can leverage our network of manufacturing and distribution assets and provide a broader range of products to our customers."

He adds that Lafarge's immediate total investment will approximate $40 million, including modifications to several cement plants and distribution terminals. The agreement with Ispat Inland expands the company's line of cementitious materials, which officials note has grown considerably through acquisitions of fly ash processors (American Fly Ash, Midwest Ash and National Minerals, now operating collectively as a Lafarge subsidiary, Mineral Solutions Inc.) in the U.S. and Canada over the past 10 years, and through internal product and market development efforts. Lafarge reported 1999 cementitious materials shipments of 2.8 million tons. The company reports more than 45 years of experience converting slag into a building material. It currently processes slag from four blast furnaces in Canada and Florida.

In Europe, use of concrete admixtures is growing over twice as fast as the concrete market itself. This trend is apparent in both ready-mix and precast segments of the industry, according to a recent study by Eldib Engineering and Research Inc., a Berkeley Heights, N.J., consulting firm.

Eldib interviewed 110 entities in Western Europe, including 12 admixture manufacturers; 49 ready-mix and 35 precast producers; eight building repair firms; and nine professional regulatory agencies. The estimated total European market for concrete admixtures is approximately US $600 million per year. The growing acceptance of water reducing admixtures (WRAs), the major additive, is fueled by lowered labor requirements and upgraded strength of concrete associated with the reduced levels of water in formulations containing WRAs or superplasticizers, researchers report.

The costliest ingredient in concrete is cement. WRAs have the ability to lower cement content in the formulation without the sacrifice in strength that would otherwise occur. Recent improvements in the performance of WRA admixtures have also spurred increased acceptance. >From the large-volume, low-cost lignosulphonates used at first, recent admixture formulations comprise naphthalene lignosulphonates, melamine sulphonates and polyhydroxyl carbon acids that can improve water reduction and concrete flow properties.

For precast concrete members, WRAs can provide improved efficiency in molds or forms usage, greater strength and better surface appearance. Users find that a reduction in cement needed in the formulation will usually compensate for the additional cost of the WRAs. In addition, based on extensive interviews among ready-mix and precast producers and users, Eldib finds that the labor savings are generally sufficient to justify a premium WRA-bearing mixes.

Andrew Eldib, who headed the investigation, notes, "Our survey and market analysis concludes that new suppliers of WRA-mostly chemical companies or their affiliates producing specialized surface active agents-would find a place for their product in the European construction firms market. New suppliers can come from Europe, Japan and the U.S." Eldib believes that demand for water-reducing agents is growing faster than capacity. A boon for WRAs is in the offing, he contends, subject to sufficient supplies of chemical ingredients.

Europe's WRA usage varies extensively. Acceptance and growth in England is considerably slower than in Sweden, where labor costs easily justify WRA or superplasticizer premiums and foster the popularity of self compacting concrete. According to the Eldib study, WRAs' growth potential is also shaped by European countries' per capita concrete consumption.

An even greater influence on acceptance and growth results from local industry and architectural preferences. Very high usage and growth are taking place in Italy (1.1 cu. m of concrete per capita) and Ireland (0.85 cu. m per capita), where per capita consumption of concrete is already at high levels compared to England (0.4 cu. m per capita) and France (0.5 cu. m per capita), Eldib researchers report. Even in England, the use of WRAs in ready-mix has been steadily increasing yearly from about 15 percent of the market in 1988 to over 55 percent in 1998. Also significant in driving demand are some select major construction projects consuming large amounts of WRAs. Reunification of the economically deprived East Berlin with modern West Berlin, for example, has created a boon for Germany.

Europe's largest producers of WRAs and superplasticizers are SKW-MBT, Sika, Grace, Addiment, and Tricosal. While there is considerable vertical integration in the cement/concrete and admixture arena, European suppliers tend to provide the formulated product while relying on the chemical producers for their raw material supply of the surface active agents, etc., according to Eldib.