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No. 356-B

Specification

EVAPRE™-RTU

READY-TO-USE EVAPORATION RETARDANT

DESCRIPTION
EVAPRE-RTU Ready-To-Use Evaporation Retardant is an economical, high quality, water-base compound. It is specifically designed to form a thin monomolecular film to reduce rapid moisture loss from the concrete surface prior to curing. EVAPRE-RTU provides a significant aid in producing high-quality concrete flatwork. Rapid evaporation of water is retarded, slab surface conditions are normalized, and workers can adhere more closely to established finishing schedules when using EVAPRE-RTU. EVAPRE-RTU is also VOC compliant.

EVAPRE-RTU significantly reduces plastic shrinkage and cracking, wind crusting, stickiness and sponginess, which often cause poor and uneven surface texture. These conditions result when the hydration is more rapid than the movement of bleed water to the surface. EVAPRE-RTU effectively combats and minimizes the effects of rapid drying conditions, such as low humidity, low dew point, high winds, direct sunlight, hot weather, heated concrete or placement of concrete in a heated enclosure or interior area during cold weather. The protective film shield disappears as soon as the concrete is no longer plastic.

USES
EVAPRE-RTU is ideal for use as an evaporation retardant for concrete surfaces where the evaporation rate exceeds the rate of bleeding. EVAPRE-RTU can be used with condensed silica fume concrete, concrete containing fly ash and all cementitous products. When applying surface hardeners, EVAPRE-RTU can be used after screeding and after the first floating operation, if necessary.

NOTE:
EVAPRE-RTU is specifically designed to fight off the destructive effects of early rapid evaporative moisture loss. Early rapid evaporative moisture loss is addressed in ACI Committee 305R-91, entitled “Recommended Practice for Hot Weather Concreting.” This report contains a chart on page 5 that depicts the effect of concrete and air temperatures, relative humidity and wind velocity on the rate of evaporation of surface moisture from concrete. It provides a graphic method for estimating the loss of surface moisture for various weather conditions.

FEATURES/BENEFITS
• Significantly reduces plastic shrinkage and cracking caused by evaporation in low humidity, high temperatures and high winds.
• Allows use of lower slump & lower water: cement ratio concrete.
• Provides smooth and durable concrete flatwork.
• Reduces wind crusting, stickiness, and sponginess, which often cause poor and uneven surface texture.
• Allows finishing crews to adhere to established schedules.
• Reduces overall cost because timing of finishing operations is less critical.
• VOC compliant.
• Helps minimize surface cracking due to early water loss of silica fume concrete.

APPLICATION
STEP 1- Agitate EVAPRE-RTU before applying.

STEP 2- Apply EVAPRE-RTU with a commercial sprayer. Use a Chapin 1-5797 or equivalent spray tip that produces a flow rate of one-half gallon per minute.

STEP 3- EVAPRE-RTU should be applied immediately after screeding and/or between finishing operations, as needed. Application is simplified by the fugitive pigment, which will disappear completely upon drying. Do not allow puddling. If puddling occurs, wipe up immediately and rinse with water.

STEP 4- Clean all equipment immediately after use with soap and water.

STEP 5- Finish concrete surface as required.

STEP 6- Cure concrete after bleed water or excess surface water has dissipated. The use of EVAPRE-RTU does not negate the need for a quality concrete curing or curing and sealing compound from W. R. MEADOWS.

NOTE
The residue remaining on the surface after finishing will not impair bonding or alter color. The protective shield usually lasts as long as the concrete is plastic. Therefore, all concrete surfaces must be properly cured, as well.

PRECAUTIONS
DO NOT USE EVAPRE-RTU as a finishing aid for cementitious materials, including dry shake surface hardeners or toppings. EVAPRE-RTU should not be worked into the concrete surface, nor should it be used to re-temper the concrete. EVAPRE-RTU should not be applied during final troweling operations. EVAPRE-RTU is not a curing agent.

W. R. MEADOWS is not responsible for compatibility or results when EVAPRE-RTU is used with other manufacturer's products.

Read and follow application information and use in accordance with the Health and Safety Information shown on the container label. Refer to Material Safety Data Sheet for complete health and safety information.

This material last updated March 2007.