Research Examines Concrete in Seismic Zones in Greece

Brief 

Researchers in Greece studied the differences in cost for a five-story concrete building across the country’s three earthquake hazard zones using building modeling and analysis. Researchers concluded the rate of increase in construction costs from one earthquake hazard zone to another was small in relation to the increase in seismic acceleration, and if engineers prefer to design buildings for a higher seismic zone to improve safety, it can be done without significant increase in material costs.

Insight

For concrete contractors, screeds are an essential purchase and a critical tool for providing the smooth, level finish for concrete work. By carefully considering the screed types available, contractors can see maximum productivity from their investment.

The most common screed categories include roller, truss, laser, power and hand screeds. Each screed has unique features that, when aligned with project goals, can improve ROI. Here is a breakdown of the features and benefits of the most widely available screeds on the market today.

Hand Screeds for Low Cost

Classic hand screeding, which traditionally uses a wooden board, might cut it for the one-off small concrete job, but any serious contractor knows the life-long pains that come from years of stooping over a heavy board and sawing it back and forth along forms to screed concrete.

Although the materials have evolved over time from hefty two-by-four lumber to lighter-weight aluminum alloy bars, the design and method has largely remained unchanged.

In addition to the back-breaking labor, hand screeding methods using boards require the skill of an experienced professional to remain true to grade and achieve consistent results since there’s no mechanical assistance. This can prove challenging on large pours, even with decades of experience.

Floating or Power Screeds for Single Operators

In what could be considered an assisted hand screeding method, power screeds, also known as wet screeds, consist of an engine or electric battery-powered motor and an extended handle placed in the center of a traditional board/blade that is in contact with the concrete. Power screeds use vibration to help the blade level the concrete.