A review of high-range water reducing admixture offerings from key sources demonstrates how polycarboxylate technology remains at the forefront of concrete mix designs and plant or field practice.
A polycarboxylate high range water-reducing admixture, Plastol 6400 enables production of concrete with very low water-cement ratios. It yields flowable and self-consolidating mixes at low doses, provides improved air stability characteristics, and can help practitioners attain up to 45 percent water reduction. When used in precast concrete along with Type I and Type III cements, Plastol 6400 contributes very high early strengths.
Plastol 6200EXT, also a high range water-reducing polycarboxylate, is specifically engineered to provide extended workability retention, minimizing the need for job site slump adjustments while maintaining consistent air content from batching to placing of concrete. In addition, the admixture maintains the typical benefits of polycarboxylate technology of high compressive strength, flexural strength, and excellent setting characteristics.
Both Plastol 6400 and Plastol 6200EXT comply with the requirements of ASTM C 494, Types A and F, AASHTO M 194 Types A and F, and ASTM C 1017 as a Type I admixture. Plastol 6400 also meets the requirements of ANSI/NSF STD 61 for use in water treatment facilities. — Euclid Chemical Co., Cleveland, www.euclidchemical.com
GCP APPLIED TECHNOLOGIES
Company’s concrete admixtures result in a carbon dioxide emissions reduction upward of 13 million tons annually. Its superplasticizers lower the amount of cement needed in concrete while preserving compressive strength, thereby reducing the embodied carbon footprint of each batch.
Phoenix ready mixed producer Hanson Aggregates LLC recently used GCP’s WRDA 64 water reducer with ADVA 195 superplasticizer for construction of the Arizona State University Interdisciplinary Science & Technology center in Tempe. “ADVA gave us the opportunity to keep the water/cement ratio low while achieving high strength as well as the workability to place the concrete very easily,” says Hanson Aggregates Quality Control Manager Bill Wheeler.
“GCP’s admixtures played a big part in the success of this mix design, helping with water reduction by using WRDA 64 and increasing concrete workability by using ADVA 195,” adds counterpart Joel Lopez Martinez. — GCP Applied Technologies, Cambridge, Mass., www.gcpat.com
KreteSuperPlast polycarboxylate admixtures are formulated to improve green strength and surface texture; impart proper mix spread without aggregate segregation; produce concrete mixes requiring little or no vibration; and, yield hardened elements or structures with sharp corners and edges. KreteSuperPlast 700 is designed to offer superior plasticizing action, mid to high range (25-40 percent) water reduction, and densification in precast and self-consolidating concrete mixes. KreteSuperPlast 710 nets comparable characteristics and mid-range water reduction (15-25 percent).
Both admixtures are dosed at rates of 3 oz. to 16 oz. per 100 lbs. of cementitious material, and ship in 330-gal. totes, 55-gal. drum or 5-gal. pails. The KreteSuperPlast series is part of a broad offering of admixtures primarily suiting manufactured concrete, dry or wet cast. The company also offers fully customized and professionally installed dispensing equipment, operating independently or integrated with batch panel systems. — Krete Industries Inc., Brookfield, Wis., 800/777-9562; www.krete.com
MASTER BUILDERS SOLUTIONS
Self-consolidating concrete is a highly fluid and stable mixture that flows into place without the need for mechanical consolidation. SCC characteristics are defined by filling and passing ability, plus stability. Use of material has the potential to reduce labor costs, shorten the project schedule, and improve a structure or element’s final surface appearance. SCC mixtures and Glenium series superplasticizers are the subject of an in-depth presentation, Let’s Talk Concrete! Livestream, on www.master-builders-solutions.com/en-us. The company provides concrete technology expertise plus chemical admixture understanding to ensure required performance on SCC projects. — Master Builders Solutions, Beachwood, Ohio
Polycarboxylate superplasticizers such as Dynamon SX have emerged as one of the most important admixture classes due to their superior performance in fresh and finished concrete. Even at low water to cement ratios, they require relatively low dosages, allow for greater flexibility in the batching process, and reduce the amount of binder needed while still attaining hardened property requirements and exhibiting long slump retention capability.
Concrete bearing Dynamon SX has a high level of workability; offers excellent mechanical performance and cohesiveness; and, maintains high mechanical strengths, making it particularly suitable for self-consolidating mix designs. The water-reducing admixture accelerates casting operations as the concrete it yields can be placed without vibration. Polycarboxylate technology enables the industry to achieve new capabilities in the production, placement, and service life of concrete mixes. — Mapei Corp., Deerfield Beach, Fla., 800/426-2734; www.mapei.us
High-quality self-consolidating concrete exhibits stable performance owing to technologies such as polycarboxylate-based superplasticizers, viscosity modifying agents, and powerful slump retaining products. Polycarboxylate superplasticizers are the most common form of water-reducing technology for SCC mixtures because of theirs potent cement dispersing capability. This achieves high slump-flows, extended workability retention, and increased thixotropy of the concrete in its rested state, which increases static stability.
Sika ViscoCrete products encompass a group of polycarboxylate-based, high-performing, water-reducing concrete admixtures. From conventional to high-strength SCC, ViscoCrete agents are specially formulated to provide full range water reduction with a variety of cementitious materials allowing for ultimate versatility. As the world’s largest supplier of polycarboxylate technology developed specifically for cement and concrete production, the company understands the building blocks of polymer design. The result is products that are less sensitive to the many variables that can affect concrete, providing producers and their customers greater consistency. The latest generation of ViscoCrete and ViscoFlow admixtures allow for economical water reduction, resulting in increased concrete durability. These products target various producer or contractor needs, whether it be long slump retention typically needed in ready mixed concrete and cast-in-place practice, or high early strength gain required in precast, prestressed production. — Sika Corp., Lyndhurst, N.J., www.usa.sika.com