Overview of Crazing of Polished Concrete Surfaces

Overview of Crazing of Polished Concrete SurfacesCrazing refers to the network of fine cracks that can be present on the surface of concrete. Sometimes called map-cracking or alligator cracking, crazing is created due to sub-optimal curing methods and conditions at the time of placement and finishing. While polishing concrete does not cause or exacerbate crazing, a highly refined surface can accentuate the fine cracks and cause them to stand out. It can be beneficial for a polishing contractor to be able to explain the causes of crazing and even to point out its existence in an existing slab prior to executing a contract.

Crazing occurs due to the shrinkage of the mechanically densified dewatered paste cap, often due to poor curing conditions that allow for too fast of evaporation rates or from too wet a mix. To minimize the potential for crazing, proper curing methods should be started as soon as possible. Wet curing, blanket curing or the use of a membrane-forming curing compound can all retard the hydration process, which will help to prevent the rapid shrinking that causes craze cracking. Over-seeding Portland cement to soak up bleed water, or starting finishing operations while bleed water is present, will both facilitate the formation of crazing and should be avoided.

Once crazing has appeared, usually within a week of placement, there is no way to remove the crazing other than by cutting below where the cracks are, typically no more than 3-4mm below the surface. Grouting can help to disguise the craze cracks but will not typically completely hide them.

Runyon Surface Prep Rental & Supply is a full-service sales and rental facility uniquely dedicated to the concrete polishing industry. Our uniqueness comes from providing our customers with a diverse equipment, product and supply portfolio. We offer training and support, such as technique workshops on prep, polishing or removal, and maintain a well-stocked inventory of consumables ready for your projects at a moment’s notice. Rather than perform contract work ourselves, we consult on job sites when necessary. With the backing of our vendors, Runyon Surface Prep offers support at any level, to assist in helping you get things done. We can deliver or ship wherever you need, or you can pick up from our facility.


Runyon Surface Prep Heads to World of Concrete 2018

Runyon Surface Prep Rental and Supply is starting 2018 off in a big way when we head to Vegas for the largest annual international event for concrete and masonry professionals, the 2018 World of Concrete!

An estimated 55,000 attendees and 1,500 exhibitors are set to descend on the Las Vegas Convention Center January 22-26. Representatives from all over the U.S. and the world are ready to prove that the concrete industry is Vegas Proud and has been for 43 years.

Runyon Surface Prep is proud to once again be a part of the World of Concrete in 2018. Visit our booth in South Hall (#S13039), where we’re featuring our NEW Runyon Tooling Line. This Line includes the Q8 Series metal bond tools, RSP Copper Transitionals, Race Resins, Rocky DIPs (diamond impregnated pads) and hand polishing pads. We’ll also feature our most popular equipment, chemicals, contractor essentials, etc.

Acres of Exhibitions, Expert Demonstrations & Skill-Building Seminars

World of Concrete is huge! A whopping 725,000 square feet of exhibition space is filling up fast with vendors from around the globe.

  • Witness live demonstrations from industry experts and get your questions answered
  • Shop for the equipment your company needs from the representatives who understand it best
  • Choose from 170 educational courses and over 80 new sessions. The three-hour classes cover topics from concrete fundamentals and production to business and project management
  • Hear from 140 industry speakers
  • Find plenty of hands-on training, as well as certifications and exams

Where else can you learn the latest in applications and equipment, all in one place?

The countdown begins now for the 2018 World of Concrete January 22-26 at the Las Vegas Convention Center. Visit www.worldofconcrete.com to register NOW!

We hope to see you there!