Structural

May 4, 2020

Retaining Wall Material Guide

1-Retaining-Wall-Material-Guide Retaining Wall Material Guide

Retaining walls offer a mix of form and function. A retaining wall can hold back the soil behind it, playing an important role in preventing erosion, particularly on hills or in areas where plants can’t grow. Retaining walls are also used to create flat, usable ground on hilly terrain for things such as parking lots and sports fields. A retaining wall can also enhance landscape designs. For example, a landscape architect or designer might build retaining walls to create different levels of terrain or different elevations in a garden.

Retaining walls differ from the walls that hold up a building or another structure. While the walls of a home or apartment building are designed to support vertical loads such as ceilings and roofs, retaining walls are meant to support horizontal loads. For that reason, the design and engineering of a retaining wall differ from the design and engineering of the wall of a building.

While there are similarities in the types of materials used for building retaining walls and other types of walls, some materials are better suited for use with retaining walls. In this guide, we’ll take a look at some of the most commonly used materials for retaining walls.

August 5, 2019

Pouring Concrete In The Summer

Savannah Penn, PE

hose-300x208 Pouring Concrete In The Summer When the summer heats up, we often begin looking for methods of keeping things cool while outdoors. Whether we are trying to cool our gardens, our structures, or ourselves, water is considered one of the most effective tools in this regard. But not all things will benefit from added water, even on a hot summer day.

Concrete is the most widely-used building material in the world. It is celebrated for its compressive strength, which is produced by a combination of the chemical reaction between cement and water, and the presence of aggregate within the mix. The ratio between these materials within a concrete mix can have great effects on the strength of the hardened product. In particular, excessive water can have extended adverse effects on the strength of new concrete as it hardens and cures, and therefore can compromise the integrity of the resulting concrete structure.

Because of the impact that water can have on concrete strength gain, engineers have closely studied and observed the relationship between water content and concrete compressive strength. The figure below (https://www.engineeringintro.com/concrete/concrete-strength/water-to-cement-ratio/) is a graph representing that relationship, which shows the reduction of fully-cured compressive strength as the water-cement ratio is increased. The water-cement (w/c) ratio is the value of weight of water divided by weight of cement in a concrete mix. During concrete placement, the w/c ratio increases when water is added to the mix without also adding more cement. As we can see from the graph, the proportion of water within a concrete mix plays an important role in allowing the hardened concrete to reach its design strength.

hose-300x208 Pouring Concrete In The Summer

Each year, the hottest months of the summer bring plenty of concerns for new concrete, one of the primary items involving high temperatures (see our blog post, August 13, 2012). In an effort to keep a concrete mix temperature down, it is no real surprise that someone’s first instinct might be to add water. But there are other effective ways to cool concrete without compromising strength- so that we can save some water and help build stronger structures.

August 10, 2018

Teaming with Others

Mindy Maronic

Always nice to collaborate with others in the industry. Outstanding work by ETC’s Chief Structural Engineer, Chris Carlson, PE and Project Engineer, Luke Valentine, PE. Job well done!

August 17, 2017

Wood Construction Trends

Staff Writer

lobby-200x300 Wood Construction Trends Wood construction is no longer constrained to low rise buildings and single-family homes. New uses are emerging resulting from an expanded interest in wood with new trends impacting construction. Tall wood construction has resulted in multiple high-rise wood buildings around the world from the 14 story Treet Building in Norway to the 18 story Brock Commons in Canada.

The interest in wood construction has led to office buildings, apartments, and commercial spaces being constructed out of wood. To support these structures, engineers have utilized advances in engineered lumber such as using glulam (glue-laminated timber), nail laminated timber, cross laminated timber, and other forms of engineered lumber. Engineered lumber is a strong wood based composite material that is often combined with special adhesives or other methods of fixation that can be used in columns, beams, and many other applications.

Renewed interest in mass timber has also risen because of the desire to construct tall wood framed buildings. It seems everything old is new again when you consider that the Old Faithful Inn was constructed in 1904 and is the largest log hotel in the world. The advances in wood engineering and higher levels of interest have resulted in investigations into potential changes to the building code that would allow taller wood construction. These trends indicate that the future of wood as a building material for both existing and new construction is exciting and filled with possibilities.

LETS WORK TOGETHER

Continue Reading

Architectural Design in a Post-COVID World

Glass Canopy Tips

Advice From An Architect

May 22, 2017

Adding A Rooftop Deck

Shabbir Kazmi, AIA, LEED AP BD+C

shutterstock_409974142-300x185 Adding A Rooftop Deck With Summer just around the corner, you may want to consider converting that unused roof area into a gathering spot with a beautiful view. Rooftop decks can be quite appealing, but before sending out the party invitations, make sure to consider these few helpful tips

Hire a professional to specify maximum allowable occupants. Decks are designed for specific live loads (such as people, type of activity, snow, furniture) and specific dead loads (such as decking, pergola, railing). Therefore, design your deck for a specific number of people and specific activity.
Ask your design professional about cross-bracing (lateral support), a very important building code requirement that affects the overall look of the deck.
Study and understand exit requirements for your rooftop deck as specified in the building codes. Requirements for a multifamily residential building are more stringent and costlier than a single family home.
Specify proper slope for water drainage. Our recommendation is ¼” per foot, although every situation should be carefully considered. Waterproofing of your deck and roof are very important factors of your project, if not properly built or maintained, it can cause problems and expenses for the residential unit below.
Choose materials and construction details to last a long time. All framing should be pressure treated lumber and elevated above roofing material. Decking and railing material can be pressure treated or composite. Composite material is a mixture of sawdust, wood chips and vinyl. To keep it environmentally friendly, make sure the vinyl component is made from recycled plastic materials. Composite material is very low maintenance and there is no need for painting or staining.
Pay special attention to lighting and controls, especially in areas such as stairs, change of levels and door entry/exit.

LETS WORK TOGETHER

Continue Reading

shutterstock_409974142-300x185 Adding A Rooftop Deck

Leading The Way In New Hotel Design

Lobby Design Essentials

Cleaning Solutions

October 5, 2016

Self-Healing Concrete

Staff Writer

Researchers at the Delft University of Technology in the Netherlands are working on placing bacteria in concrete mixes to fix cracks in concrete and make it self-healing. This could make concrete less susceptible to damage related to water that infiltrates a beam by way of a crack and results in rebar corrosion.

bio-concrete-300x187 Self-Healing Concrete http://www.citg.tudelft.nl/en/research/projects/self-healing-concrete/

June 7, 2016

Adding A Rooftop Deck

Shabbir Kazmi, AIA, LEED AP BD+C

roof-top-300x200 Adding A Rooftop Deck With Summer just around the corner, you may want to consider converting that unused roof area into a gathering spot with a beautiful view. Rooftop decks can be quite appealing, but before sending out the party invitations, make sure to consider these few helpful tips

Hire a professional to specify maximum allowable occupants. Decks are designed for specific live loads (such as people, type of activity, snow, furniture) and specific dead loads (such as decking, pergola, railing). Therefore, design your deck for a specific number of people and specific activity.
Ask your design professional about cross-bracing (lateral support), a very important building code requirement that affects the overall look of the deck.
Study and understand exit requirements for your rooftop deck as specified in the building codes. Requirements for a multifamily residential building are more stringent and costlier than a single family home.
Specify proper slope for water drainage. Our recommendation is ¼” per foot, although every situation should be carefully considered. Waterproofing of your deck and roof are very important factors of your project, if not properly built or maintained, it can cause problems and expenses for the residential unit below.
Choose materials and construction details to last a long time. All framing should be pressure treated lumber and elevated above roofing material. Decking and railing material can be pressure treated or composite. Composite material is a mixture of sawdust, wood chips and vinyl. To keep it environmentally friendly, make sure the vinyl component is made from recycled plastic materials. Composite material is very low maintenance and there is no need for painting or staining.
Pay special attention to lighting and controls, especially in areas such as stairs, change of levels and door entry/exit.

LETS WORK TOGETHER

Continue Reading

Creating A Desirable Break Room

Installing Linoleum on Concrete Floors

What A Load of…Information!

April 12, 2016

Don’t Forgo The Soil Sampling

Staff Writer

shutterstock_360675260-200x300 Don't Forgo The Soil Sampling Occasionally we run into a building owner that regards soil sampling and testing as an unneeded extra expense and asks if we can forgo this effort. Generally, soil is sampled by using a drill rig that bores into the ground up to 40-feet, or more deep. Small samples of the various soils that are found at different levels or strata are taken to a laboratory for testing to determine the composition of the soil, moisture content, and other properties.

In the field, the various soil types encountered are visually classified according to accepted standards and stiffness of the soil at different depths of the boring. These engineering properties are necessary to determine the type of foundation needed for a retaining wall or building, depth of a storm water infiltration facility, or even in the selection of a proper pavement profile.

Nearly all local municipalities will require soil testing for structural retaining walls (over 3-feet tall), storm water infiltration facilities, and buildings. We routinely obtain soil borings to help evaluate suspected building settlement conditions to learn the impact that the soil may have on the apparent building movement and help design the foundation underpinning repairs. If soil is not sampled and tested for its engineering properties, unexpected expenses can arise and the job progress can stop after the excavation begins and unsuitable soil layers are found.

December 3, 2015

Project Of The Year Goes To…ETC!

Mindy Maronic

In the building repair industry, there is a technical organization known as the International Concrete Repair Institute (ICRI), founded in 1988. The organization was created in response to concerns about the lack of standards and guidelines industry-wide for concrete repairs. The vision of ICRI is to improve the quality of concrete restoration, repair and protection through education of and communication among the members; and, those who use their services. Throughout the country, there are thirty-six (36) chapters that follow the guidelines and standards set by the national level. This region falls under the territory of the Baltimore-Washington Chapter of ICRI.

Once a year, each individual chapter holds a project of the year competition and accepts applications from its chapter members. Typically, the restoration projects submitted are unique and complex in nature. This year, Engineering and Technical Consultants (ETC) was awarded first place for the Baltimore-Washington Chapter project of the year.

The project submitted was for a major roof replacement at Greens I of Leisure World, 55+ community located in Silver Spring, Maryland. Please view the slide presentation to see the extent of this major restoration project.
[themify_button style=”large light-blue flat rounded” link=”/wp-content/uploads/2015-ICRI-Award_web.pdf” target=”_blank” ]View Slideshow (PDF)[/themify_button]

Congratulations to Bobby Radcliff, P.E. (ETC) and everyone involved. Job well done!

July 7, 2015

Epoxy Injection

Staff Writer

Cracks are common sign that structural failure may be occurring and can lead to multiple problems such as leaks, façade deterioration, foundation instability, etc. How can we address them?

Epoxy injection is one of the most common approaches to address cracks in structures. Structural restoration using epoxy injection had been used for decades as a system for fusing a damaged element back together thus restoring the original strength, quality and load capacity of a concrete, masonry, or wood structure.

The proper selection of the epoxy injection material depends on the width of the crack and the causes of the crack. Epoxies have different viscosities which are intended to be placed in a variety of applications. Usually, thinner (less viscous) epoxies are placed in thinner cracks, while thicker (more viscous) materials are used in wider cracks.

Epoxy injection can create an impervious seal to air, water, many chemicals, debris, and other contamination that is stronger than the parent material. The injection can also help to thwart water leakage through concrete structures and prevent corrosion of reinforcing steel by protecting it against moisture.

However, a misconception we often encounter is that epoxy can be used to seal leaking foundation wall cracks. While leaking wall cracks can be injected to stop water infiltration, epoxy is the almost always the wrong material for this application. A future posting will discuss the injection of leaking cracks.

Also keep in mind that epoxy injection will not be effective, long term, if the crack is active. Before injection, the cause of the crack, i.e. over loading, corrosion, etc., must be identified and properly addressed. If the cause of the crack is not remedied, the injected element will likely crack once again, near the repair

‹ 1 2 3 4 ›»