paper tech Unique Flexible Epoxy Systems for Flooring and Secondary Containment Leo Meilus EPIKOTE EPON EPI-CURE EPI-REZ HELOXY CARDURA VEOVA

Transcription

1 tech paper SC: Unique Flexible Epoxy Systems for Flooring and Secondary Containment By Leo Meilus EPIKOTE EPON EPI-CURE EPI-REZ HELOXY CARDURA VEOVA

2 SC: / Unique Flexible Epoxy Systems for Flooring and Secondary Containment Page 2 Abstract Introduction There are many areas where protective coatings over concrete and cementitious surfaces are required such as warehouse floors, secondary containments, control rooms, troughs and retention areas. We have all seen that new and old concrete tends to crack for various reasons and therefore it is important to counteract this, otherwise further cracking and deterioration can occur. A multi-layer system incorporating a high-grade, flexible, crack-bridging layer will ensure an optimum, long-lasting system. At first the requirements of a floor appear simple. The main requirement is the ability to withstand traffic and maintain an attractive appearance. In the case of secondary containments it would seem a thin layer of paint may be all that is required. However, closer examination reveals that there are a variety of prerequisites which include reliability and long-term stability of the floor or secondary containments. The reliability issue is especially apparent with secondary containments. From here on in the term floor includes secondary containments, warehouse floors and any other cementitious material. Cementitious materials, whether new or old, will develop small cracks and are very porous, therefore, suitable measures must be taken to counteract this. Epoxy based composite floor systems with optimized properties in which the floor system can be varied depending on the particular problem is the best solution for solving these types of situations. The diversity of Resolution Performance Products epoxy resins and curing agents makes them well-suited for composite flooring systems. By proper selection of the epoxy resinhardener components, customized systems can be used for specific requirements. Some of the main requirements for the long-term preservation of the floor include incorporating high mechanical strength, chemical resistance and the ability to bridge small cracks. Figure 1 shows a drawing of a high grade industrial flooring system utilizing a protective composite system. Each layer has a specific purpose, but the combination of all the layers provides the optimum protection. Assuming the surface has been properly prepared and cleaned thoroughly, the following is an explanation of each step in detail.

3 SC: / Unique Flexible Epoxy Systems for Flooring and Secondary Containment Introduction (cont.) Cracks Fabric Tape Primer Page 3 Figure 1/ High Performance Industrial Floor References to cracks are strictly the non-moving type and must be determined by a qualified engineer or architect. The purpose of filling cracks by gravity feed or pressure injection is to provide higher strength than the concrete itself and stop further cracking from occurring. Requirements include low viscosity for deep penetration, high tensile and flexural strength, fast set, good adhesion to the concrete and moisture insensitivity. Table 1 shows the properties of a typical crack filling epoxy using EPI-CURE Curing Agent 3374 and EPON Resin Custom Solution CS-241. The tape is applied over the filled crack and serves to prevent the tip of the crack from penetrating into the coating due to small movements in the concrete. Also, it helps relieve the tension due to slight movement. Laitance is an accumulation of fine particles, loosely bonded, on the surface of fresh concrete caused by the upward movement of water,. A primer should penetrate far enough to strengthen this layer. Any dust or particles on the surface must also be sealed to provide good adhesion to the next composite layer. Epoxy primers must be able to cure at low temperatures and high humidity conditions and be able to bond to damp concrete as well. Note in Table 1 the primer formulation is identical to the crack filling material making it much more convenient for the formulator and applicator. Thickness of the primer will range from 1-5 mils.

4 SC: / Unique Flexible Epoxy Systems for Flooring and Secondary Containment Page 4 Primer (cont.) Table 1/Crack Injection and Concrete Primer Formulations SIDE A SIDE B EPON Resin Custom Solution CS-241 EPI-CURE Curing Agent 3374 Volume 2 parts 1 part Mix viscosity Tensile strength Elongation Flexural strength Flexural modulus Compressive strength System properties 224 cps 6920 psi 10.0% 10,045 psi 0.11 x 10 6 psi 10,672 psi Dry-to-Dry Wet-to-Wet Dry-to-Dry Wet-to-Wet 765 psi 565 psi 600 psi 475 psi 77 F 77 F 45 F 45 F Adhesion to concrete 100% concrete failure 50% concrete failure 100% concrete failure 50% concrete failure Leveling Compound The primary reason for this layer is to provide a uniform surface for the flexible epoxy which will be applied subsequently. Leveling systems should be filled so that application onto horizontal and vertical surfaces is quickly and efficiently performed. Typical thicknesses will range from 1 mil up to one-half inch depending on the profile of the surface. A formulation using EPI-CURE Curing Agent 3072 and EPON Resin Custom Solution CS-241 is shown in Table 2. Table 2/Leveling Compound Side A Side B EPON Resin Custom Solution CS-241 Thixotropic fillers EPI-CURE Curing Agent 3072 Weight Flexible Membrane This layer is extremely important for bridging new cracks which occur in the concrete. Tensions caused by crack movement should be relieved in this layer. The combination of high elongation combined with high tear resistance is unique to epoxy systems. Good properties can be obtained at temperatures as low as 14 F using EPON Resin Custom Solution CS-241 and EPI-CURE Curing Agent 3266 as shown in Table 3. This crack bridging concept is illustrated in Figure 2 which is an actual copied photograph of a laboratory experiment. As the crack propagates upward into the concrete, one sees that the brittle leveling layers cannot stop the crack; however, it does stop in the flexible layer. The width of the crack is 2.75 mm at the flexible membrane. A minimum thickness of 1.5 mm is required for the flexible layer to bridge cracks. This is why the leveling compound must be used to ensure uniform thickness

5 SC: / Unique Flexible Epoxy Systems for Flooring and Secondary Containment Flexible Membrane (cont.) Page 5 of the flexible layer. Note how badly the top layer is deformed yet the composite system is still intact. Had the flexible membrane not been used, this crack would propagate right through to the top layer. When choosing a flexible material, one must take into account not only elongation but tear resistance as well. There are many ways to plasticize epoxies; however, this system is a unique polymer which does not have a high plasticizer content. Note the low viscosity of the flexible curing agent and epoxy, making it user friendly and easy to apply. Table 3/Flexible Membrane Side A Side B EPON Resin Custom Solution CS-241 EPI-CURE Curing Agent 3266 System properties Pot 77 F, 250 gm Hardness, Shore A/D 77 F, 14-day cure 118 minutes 94/74 Test conditions Properties, 7 77 F cure Tensile strength, psi Elongation, % Tear resistance, psi 77 F Figure 2/Crack Bridging Occurring in the Flexible Layer 14 F Weight

6 SC: / Unique Flexible Epoxy Systems for Flooring and Secondary Containment Page 6 Fabric and Top Layer Conclusion Reference A fabric layer is applied onto the flexible layer to further absorb and distribute potential forces from crack movement. Either polyester or nylon types are typically used. Next, the last layer is applied, selection being dependent on the individual requirements. For example, a warehouse floor on which heavy equipment such as tow motors are used will need high strength epoxy mortar while a secondary containment will need a chemically resistant topcoat. The matrix described here provides a long lasting trouble-free floor, under typical conditions in nonextraordinary applications. Each layer is important and all work together to provide high mechanical strength and crack bridging capability. Each application must be evaluated individually in order to provide optimum protection and durability. 1 Successful Coating and Lining of Concrete. Coatings Technology Institute. This document may contain starting point formulations which are not proven for use in the user s particular application, but are simply meant to demonstrate the efficacy of the products and to assist in the development of the user s own formulations. It is the user s responsibility to fully test and qualify the formulation, along with the ingredients, methods, applications, or equipment identified herein ( Information ), by the user s knowledgeable formulator or scientist, and to determine the appropriate use conditions and legal restrictions, prior to use of any Information.

7 Resolution Performance Products P.O. Box 4500 Houston, Texas For product prices, availability, or order placement, call our toll-free customer service number at: For sales in North and South America outside the United States, call: For literature and technical assistance, visit our website at: SAFETY & HANDLING These products are capable of producing adverse health effects ranging from minor skin irritation to serious systemic effects. Exposure to these materials should be minimized and avoided, if feasible, through the observance of proper precautions, use of appropriate engineering controls and proper personal protective clothing and equipment, and adherence to proper handling procedures. None of these materials should be used, stored, or transported until the handling precautions and recommendations as stated in the Material Safety Data Sheet (MSDS) or Preliminary Safety Information Sheet (PSIS) for these and all other products being used are understood by all persons who will work with them. Questions and requests for information on Resolution Performance Products LLC ( RPPLLC ) products should be directed to your RPPLLC sales representative, or the nearest RPPLLC sales office. Information and MSDSs or PSISs on non-rppllc products should be obtained from the respective manufacturer. NOTICE Any of the formulations or the ingredients in the formulations may present an unknown health or safety hazard. These are starting point formulations and are not proven for use in a user s particular application. It is the user s responsibility to fully test and qualify the formulation, its ingredients, methods, applications, or equipment identified herein ( Information ), by the user s knowledgeable formulator or scientist, and to determine the appropriate use conditions and legal restrictions, prior to use of any Information. Reference to any commercial ingredient, process, or service by trade name, trademark, or manufacturer does not constitute or imply its endorsement, recommendation or favor in the formulation or for use in the user s application. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY EXCLUDED AND DISCLAIMED. WITHOUT LIMITATION, NO REPRESENTATION IS MADE AND NO WARRANTY, EXPRESS OR IMPLIED, IS EXTENDED WITH RESPECT TO THE ACCURACY, REPRODUCIBILITY, COMPLETENESS, OR USEFULNESS OF THE INFORMATION TO MEET YOUR REQUIREMENTS, OR WITH RESPECT TO THE TITLE OR MERCHANTIBILITY OF THE INFORMATION PROVIDED, OR THE FITNESS OF THE INFORMATION PROVIDED FOR A PARTICULAR PURPOSE, OR THAT THE USE OF THE INFORMATION IS FREE FROM INFRINGEMENT OF ANY PATENT OR ANY OTHER INTELLECTUAL PROPERTY RIGHT, AND EACH OF THESE ARE THE SOLE AND EX- CLUSIVE RESPONSIBILITY OF THE USER. Use of the Information is at your own risk. No opinion, advice or Information, whether oral or written, obtained by you in any manner from us pertaining to the Information shall create any warranty of any kind. Your reliance on the Information presented herein for use in a particular application shall indicate your consent that in no event will Resolution Performance Products LLC or any of its affiliates be responsible for any damages of any nature whatsoever resulting from the use of or reliance upon the Information Resolution Performance Products LLC. All rights reserved. SC: Printed in the U.S.A. 11/01 EPIKOTE EPON EPI-CURE EPI-REZ HELOXY CARDURA VEOVA