EQUIPMENT DEVELOPMENT COMPANY, INC - SINCE 1959 FLOOR GRINDING & SURFACE PREPARATION, CONCRETE POLISHERS REMOVAL & DEMOLITION, CONCRETE SAWING & DRILLING MASONRY, HARDSCAPE & TILE SAWS, HANDHELD TOOLS CONCRETE DUST EXTRACTION EQUIPMENT & INDUSTRIAL CLEANING July 2014 AMERICAN MADE BUILT TO BE RENTED TM EDCO in Frederick, Maryland Computer-controlled machining of parts High-strength welded Who We Are: construction Long-lasting coatings In 1959, EDCO began with 3 entrepreneurs designing and manufacturing a few construction products. Today, our company is a world-class manufacturer. We offer a full line of surface preparation & professional sawing equipment, concrete polishing machines, hand tools, and complete contract manufacturing services. EDCO products grind, remove, clean, texture, saw, prepare, and finish concrete & other surfaces. What We Believe : EDCO products. We areWe trainers believe beforein Training. sellers. We provide our customers the knowledge needed to be successful with We believe in Technology. YouTube to Twitter to Webinars,EDCO and invests QRC Decals, in both we customer love web-based training training tools and technology. manufacturing All customers technology. are From sup- ported by those online training tools and our network of sales representatives. We believe in Quality & Safety. one modern facility in historic Frederick,To ensure MD. Fromboth ,Laser EDCO Fabricating practices LEAN to Powder Manufacturing Coating to and CNC creates Machining, its products our facility inside contains the latest manufacturing equipment and software. We believe in American Manufacturing. move over seas and back when convenient, we believe in the importance of staying home and working smarter. We say EDCO products “Stayed In America”. While other manufacturers EDCO’s commitment to American manufacturing is unwavering. What Keeps Us Up At Night : EDCO Fabrication customers deserveEveryone safe, long-lasting at EDCO understands products and we ourdon’t help exist making without them our successful. customers. We EDCO can’t and rest until all questions are answered. Some companies just say they answer all inquiries, we actually do. Test us! Who Do We Want To Be: to continue creating. We striveWe wantto be toahead be our of customers’the curve. We most want trusted to be vendor. proud. We want to be the leader. We want Worldwide Representation / Shipping: can deliver products and supply you with the necessary in-person or online training. EDCO representation covers the planet. No matter where you are, we Assembled and inspected to exact standards Expert Customer Service Representatives. Ships all over the Globe AMERICAN MADE AMERICANAMERICAN MADEMADE AMERICAN MADE MANUFACTURED PROUDLY IN THE USA MANUFACTURED PROUDLY IN THE USA EVERYTHING YOU WANT TO KNOW ABOUT CONCRETE FLOATING The purpose of floating is threefold: is a mixture of port- Concrete • to embed large aggregates just beneath the surface, land cement, water, fine and • to remove slight imperfections, bumps and voids, producing coarse aggregates, and sometimes a level or plane surface, entrained air or other special • to consolidate mortar at the surface in preparation for other purpose additives. Cement is an finishing operations. ingredient of concrete, not an interchange-able term for concrete! After the concrete has been properly placed, struck off, bull-floated or darbied, floating can take place. The purpose of floating is three fold. Floating embeds large aggregates just beneath the surface, it removes slight imperfections creating a level plane, and consolidates mortar near the top of the slab. The time lapse be- Masonry is shaped or molded tween bull-floating and power floating units of stone, ceramic, tile, varies between 2 and 8 hours, but when concrete, glass, adobe, terra- the water sheen on the concrete has dis- cotta, or similar material that is appeared, you will know the concrete is usually bonded by mortar. ready for power floating. A power trowel’s float blades are designed with up turned edges. These edges allow the concrete to roll before and under the blade compacting all the aggregate below the surface. Continue to float the surface until the entire slab is smooth and level. To help in the smoothing process, power trowels equipped with leveling systems change the pitch of the trowel blades in- is refined from crude oil Asphalt stantly. This action allows the operator to by the petroleum industry. fill in valleys and level high spots with ease. Asphalt remains solid or semi- solid if the temperature is kept below 100o F. When used in construction or maintenance FINISHING of roads and highways or as a patching material, it must be Just before the concrete sets up, the finishing process can begin. The goal of made liquid and combined with finishing is to leave the slab hard and smooth. When finger pressure on the con- fine sands and a variety of sizes crete just dents the surface, the conditions are right for finishing. Unlike float of aggregates and placed before blades, finish blades have straight edges and are made of hardened steel. This the mixture drops below 200o F. material withstands the abrasive nature of concrete. When finishing the concrete with a power trowel, the operator must tilt the finish blades slightly. Typically, a 3 to 5 degree tilt is standard, but the concrete’s hard- ness will ultimately dictate the necessary tilt. Care should be exercised by the operators as over tilting can scar the surface. After finish troweling, a non-slip concrete surface can be achieved by brushing the slab with a long handle push broom. 21800-638-3326 • edcoinc.com EVERYTHING YOU WANT TO KNOW ABOUT CONCRETE JOINTS Glossary Temperature changes, drying out, and shrinking can cause a concrete slab to crack. In order to control this cracking, joints must be cut after finishing. Air-Entrained Concrete: Concrete containing microscopic air bubbles generated by the use of an The purpose of joints is twofold: to reduce the slab’s thickness, and create air-entraining admixture to improve resistance to weakened points in the concrete that induce cracking only in those spots. freezing and thawing. Bleeding: The rising of water to the Cutting joints becomes conven- surface of freshly placed concrete. ient with a gasoline or electric power saw. With an upcut rota- Blisters: Shallow, dome-shaped surface defects on a flat work surface, seldom apparent until after tion and a diamond blade, joints first troweling. Created when entrapped air bub- can be cut as soon as the surface bles rise and swell a thin layer of surface concrete. is firm enough to not be torn or Crazing: damaged by the blade—typically, The overall pattern of random hairline cracks in a concrete surface caused by drying and shrink- 4 to 12 hours after the concrete age stresses. It is usually caused by an excess amount of slab has been placed and fin- fines on the surface. ished. Normally, joints are cut to Curled Slab: Curling is the distortion (rising up) a depth ¼ the thickness of the of a slab’s corners or edges due to differences in slab. moisture content or temperature between the top and bottom of a slab. Delamination: Delaminated areas of surface CURING mortar result from bleed water and bleed air being trapped below the prematurely closed (densified) The curing of a concrete slab is mortar surface. Bleeding has NOT occurred and the one of the most important operations in construction. Sadly, proper curing water is trapped below the surface. is often neglected. Under normal conditions, concrete reaches its designed Dry Shake: A dry mixture of cement with special strength in 28 days. mineral or metallic aggregates used to produce a hard monolithic surface. A dry shake with a pigment will produce a colored surface. To make sure a newly poured slab cures correctly reaching it maximum po- tential, care should be taken to protect it from drying too quickly. Burlap or Dusting: The appearance on the surface of hard- canvas coverings can be placed on the concrete and kept continuously wet ened concrete of a powdery material coming from the concrete itself. to protect the slab from the sun and drying winds. As soon as the concrete has hardened enough not to be marred, moistened earth, sand or straw can Laitance: A weak, milky layer of cement and replace the burlap coverings. This material should remain moist on the sand fines that rises to the surface of over wet concrete and mixes with bleed water, usually as a slab for at least 3 days. result of premature finishing. A proper slab can also be cured through the use of watertight paper or poly- Mil: A unit of length equal to one thousandth ethylene film coverings. When using those coverings, laps in the material (10 -3) of an inch (0.0254 millimeter), used to specify should be taped to prevent moisture loss. the diameter or thickness of materials. Mortar: In concrete work, the mixture PSI of cement paste and fine aggregate. In coatings, epoxy mortars combine fine aggregate with an The hardness of concrete is referenced by its compressive strength meas- epoxy for increased strength or chemical resistance. ured in Pounds per Square Inch (PSI). Cured concrete slabs vary widely in Nonslip Aggregates: Commonly silicon car- strength. Variables including moisture, temperature, additive mixture, and bide or aluminum oxide grains applied as a dry curing process, often determine level of strength. High compressive shake to produce a nonslip finish. strength means hard material. Scaling: Scaling is a scabrous condition where the surface mortar has peeled away, usually exposing the coarse aggregate. EDCO has provided this information as a helpful overview. You’ll find additional detail in Spalling: The flaking away of the surface ACI Journals and publications by Portland Cement Association, and numerous trade and of a hardened concrete slab to a depth of about 1/16 professional associations. After concrete has hardened, problems may still arise or to 3/16 inch, but it can be much deeper with loss of construction plans may be altered, and you can rely on EDCO equipment to assist you in coarse aggregate.