1- Batching, Mixing, Placing, and Finishing Steel Fiber-Reinforced Floors
2- Voids Beneath Slabs-on-Ground
3- Twisting Moments in Two-Way Slabs
4- Foundations Subjected to Vibration Loads
5- Cold Weather Foundation Construction for Sakhalin II

1- Batching, Mixing, Placing, and Finishing Steel Fiber-Reinforced Floors

Steel fiber-reinforced concrete contains short discrete fibers that must be uniformly distributed and randomly oriented throughout the concrete to improve its structural properties. Construction procedures for slabs-on-ground don’t differ greatly from those used in conventional concrete, but there are some key SFRC slab installation items that should be kept in mind to make the project go smoother. Mixture selection, mixing methods, placing, finishing, and jointing for steel fiber-reinforced concrete slabs are covered.

2- Voids Beneath Slabs-on-Ground

Concrete slabs-on-ground are popular for research facilities because they don’t exhibit the resonance characteristics of suspended slabs. Occasionally, a slab-on-ground separates from the subgrade, leaving a void that allows the floor to behave more like a suspended slab and may lead to cracking. To detect these voids, determine their horizontal extent, and verify that corrective actions have been successful, the frequency-dependent response of the slab to an impact load can be measure using impulse-response testing. The results of one such study, with measurements before and after remediation by grout injection, are presented. 

3- Twisting Moments in Two-Way Slabs

In contrast to traditional strip methods for two-way slab design, finite element analysis (FEA) automatically provides deformation compatibility and a full equilibrium load path. Designers using FEA, however, have often blindly ignored twisting moments that occur on the edges of the elements because they are not sure how to account for them. This assumption may be unconservative where torsion is high. The available methods for explicitly incorporating twisting moments in the design of slabs based on FEA results are discussed in this article.

4- Foundations Subjected to Vibration Loads

The structural design and rigorous analysis of a foundation system supporting dynamic equipment is complex. Therefore, designers often follow rules of thumb for their design. These rules of thumb, however, may lead to oversized foundations. To optimize slab size while avoiding resonance and ensuring minimal human perception of vibrations, practical guidelines and recommendations for design are presented. The effects of changes in foundation dimensions, operational speed of the equipment, and modulus of subgrade reaction on a slab’s natural frequency and peak displacement are also discussed.

5- Cold Weather Foundation Construction for Sakhalin II

One of several projects related to oil and gas exploration on Sakhalin Island, located on the east coast of Russia and north of Japan, was recently completed. The construction of mass concrete foundations for much of the equipment faced two main challenges that compounded each other: they were constructed during the coldest time of the year, when the daily mean temperature in the coldest month can drop to only -11.4 °C (11.5 °F), and the concrete contained a high slag cement content blended cement for durability. These technical challenges, along with difficulties brought on by language and cultural barriers, are discussed.