Risky Business

Strategies to utilize when employees cause accidents.

By William Atkinson

On the subject of discussing employer vs. employee responsibility for safety, industry and safety experts are mired in controversy and sensitivity. Merely suggesting that employees might be responsible for accidents and injuries, even to some degree, can lead to some heated arguments. In fact, many experts shy away from even discussing the possibility, preferring to spotlight employer responsibility.

Yet, by failing to take a hard look at this issue, employers may have difficulty reducing workplace accidents and injuries below a certain level. Read More »

Dry-Cast Basics

Dry-cast production can significantly increase production efficiency.

If you have pondered but not yet made the jump to dry-cast concrete production, chances are you have uncovered more questions than answers. Here are some dry-cast basics that may make your jump a little easier.

Dry-cast concrete mixes, also known as no-slump mixes, are used in precast plants to produce essentially any precast-concrete product. They can significantly increase production volume and lower both material and labor costs. Other benefits, such as increased strength and durability, can be realized with the low water-cementitious material ratio mixes.

Of particular interest to precasters is the increased production efficiency due to the very early product handling strengths and the ability to immediately remove and reuse forms. However, proper manufacturing equipment and techniques must be used to achieve these benefits. Read More »

Supplemental Wastewater Treatment Systems

Precasters are preparing for an inevitable future demand.

The quality of on-site wastewater is a growing concern, especially with many new homes and businesses using on-site treatment instead of a centralized sewer. With construction on the rise, the area and type of soil needed to perform adequate treatment is not always available. One way to overcome site hindrances and achieve high-quality wastewater effluent that meets federal environmental regulations is to use additional treatment systems such as media filters, natural systems, and aeration treatment units along with primary treatment systems like precast watertight septic tanks and drain fields. Many precast manufacturers are preparing for changing regulations by implementing these supplemental systems, which are in demand already. Read More »

Adding Years to Manholes

Using liners to prevent concrete corrosion and groundwater infiltration.

By Jack Klein

Precast concrete has always been the ultimate product choice used to build municipal sanitary sewage systems throughout the world. Preferred because of its strength and durability, millions of tons of precast concrete have successfully served the concrete needs of many countries for decades. In some areas, however, deteriorating conditions have created a new challenge for the precast industry: how to prevent corrosion of concrete caused by sewer gas.

Even at a time when an ever-increasing population is requiring urban municipalities to expand their wastewater collection systems, existing systems are beginning to disintegrate. A common cause of deterioration of concrete manholes er, causing corrosion of the concrete. Read More »

Using Fly Ash in Concrete

What to look for when using fly ash in precast products.

By Arnie Rosenberg
Dr. Arnie Rosenberg is a former research director at Grace Construction Products and now a guest researcher at the National Institute for Standards and Testing, working on the characterization of fly ash.

All precast concrete producers can now use a group of materials called “fly ash” to improve the quality and durability of their products. Fly ash improves concrete’s workability, pumpability, cohesiveness, finish, ultimate strength, and durability as well as solves many problems experienced with concrete today–and all for less cost. Fly ash, however, must be used with care. Without adequate knowledge of its use and taking proper precautions, problems can result in mixing, setting time, strength development, and durability. Read More »

Employee Fatigue: The New Epidemic in the Precast Industry

By William Atkinson

If you’re a precast company committed to employee safety, workforce productivity, product quality, customer service, and environmental friendliness, there’s a good chance you’ve implemented several programs that directly address all of these challenges. New medical research, however, is beginning to show that, in spite of all your best efforts, you’ve only begun to scratch the surface of tackling these concerns if you haven’t addressed one very important issue: employee fatigue.

Some statistics to consider:

• The October 1997 issue of the National Safety Council’s Safety & Health reported that the cost of accidents worldwide in which employee fatigue plays a part exceeds $80 billion a year. (Remember Three Mile Island, Chernobyl, and Exxon Valdez?)
• The National Commission on Sleep Disorders Research estimates that, in the United States alone, businesses lose more than $150 billion a year in productivity as a result of employee fatigue.
• A nine-year California study (reported in the March 1995 issue of Safety & Health) found that people who slept six hours or less each night had a 70 percent higher mortality rate than those who slept seven or eight hours. Read More »

Recommendations for Designing Grease Interceptors

And the added benefits of constructing them with precast concrete

By Michael Fankel, CIPE

Large precast concrete grease interceptors have a proven history of adequately separating grease from wastewater before being discharged into sewers at regulation quality. This is precisely what jurisdictions want a grease interceptor to do. But as more of these large precast grease interceptors are specified, questions arise about how to size and configure them. The Water and Wastewater Section of National Precast Concrete Association (NPCA) recently sponsored research on large-volume grease interceptors to develop sizing and geometry recommendations. This article contains the results of that research and is considered to be recommendations only-not standards-at this time. Read More »

Workplace Ergonomics

What to watch for, how to prevent the related aches and pains your employees experience, and why it could be critical that your company develop a cost-effective ergonomics program in the near future.

By William Atkinson

Editor’s note: The ergonomics regulations proposed by the U.S. Occupational Safety and Health Administration (OSHA) are controversial and opposed by many employers and interest groups. This article attempts to communicate the possible implications of the regulations to precasters and to suggest methods to reduce the risk of ‘ergonomics-related’ injuries, insofar as such injuries are presently understood. The article makes no attempt to create a definition of ergonomics injuries, to enumerate all the liabilities to an employer resulting from ergonomics regulations, or to advocate for or against the need for such regulations. NPCA is, however, urging congress to support legislation that would prevent OSHA from enacting the regulations until the National Academy of Sciences (NAS) completes its comprehensive study on workplace ergonomics.

In June 2000, the House and Senate approved a U.S. Department of Labor spending bill that included an amendment that prohibits OSHA from using funds in 2001 to develop and enforce its ergonomics standard. This amendment is unusual as congress doesn’t normally rule on funding issues until the end of a fiscal year. Read More »

Pre-Cast Tunnel Is Cost-Effective Option for CSO Storage Project

By John L. Murphy, P.E., James D. Ring, P.E., and James F. Seiler, P.E.

Back in 1968, the city of Bangor, Maine, constructed a wastewater treatment plant and a nine-mile interceptor sewer system to collect flows from 25 sewers that discharged wastewater into the Kenduskeag Stream and the Penobscot River. Combined sewer overflow (CSO) structures were built at 22 of these discharge points.

In the mid-1980s, however, the city discovered that the CSO structures were becoming a significant source of waterway pollution, because they allowed four times the normal untreated dry-weather flow into the river and stream during rainfalls and snowmelts. Read More »

Sulfate Attack on Precast Concrete

How precast manufacturers can prevent their products from being damaged by sulfate.

By Jan Skalny
Jan Skalny is a writer, researcher, editor and consultant specializing in the concrete industry.

Concrete is the most versatile and widely used construction material available. It is inexpensive and its components are manufactured from raw materials abundant the world over. Concrete is a composite material which, in its simplest form, is produced from coarse and fine aggregate, portland cement, and water. The function of the cement is to react with water to form the cement paste that glues the aggregate particles together into an artificial stone: concrete. Read More »