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Introducing The Great Shabbir Kazmi, AIA
Please give a warm welcome to Shabbir Kazmi, ETC’s new lead architect!
Shabbir grew up in Northern Virginia and attended Catholic University in Washington DC where he received his architecture degree. Shabbir has practiced architecture in the Greater Washington Metropolitan area for over 14 years. His design work ranges from small custom renovation projects to many larger and more detail oriented designs. Whether it’s new construction or rehabilitation, Shabbir looks forward to creating a plan that exceeds your expectations.
When Shabbir is not designing for ETC, he enjoys fixing/collecting antique furniture, yoga, spending time with this lovely wife Mariam and traveling the United States. Apparently from the photo, he’s also pretty good at taking selfies.
Nano-Technology meets Construction
A new nano-technology process that layers carbon steel elements with corrosion resistance and strength increasing materials is being tested.
The steel is run through an electroplating bath and various layers of metals are applied to the steel, which is reported to increase the steel strength by up to ten times. High strength and corrosion resistance are a great combination for a material that could be used to repair a steel building.
The following website as more information: http://www.technologyreview.com/news/534796/nano-manufacturing-makes-steel-10-times-stronger/ We will keep an eye out for more developments in this exciting technology.
Road Renovation
Green construction and sustainable buildings have been on the rise in the past few years. As technology advances, society has been attempting to create more environmentally friendly structures. The next step in sustainable structures is green roads, such as the new one in Houston, Texas.
The Bagby Street Reconstruction Project in Houston, TX, is the first project to achieve the Greenroads Certification in the state. The project also received a Congress for the New Urbanism (CNU) Charter Award for Best Street.
So, what earned the Bagby Street renovation so much praise for its sustainability? The green features of the street include the installation of rain gardens, LED street lighting, use of cool pavement materials with recycled content, locally sourced construction materials, and the addition of native and adapted vegetation that provide additional shading. All of these characteristics promote low-impact development and the reduction of carbon emissions.
The concept of “green roads” will surely begin to be implemented in other parts of the United States. The city of Houston already has plans to renovate Bagby’s sister street, Brazos Street
What is Shotcrete?
You’ve probably seen it before in your lifetime, but you may not have known it. Shotcrete is a construction technique that involves spraying concrete through a hose at very high speeds. It is a process rather than a specific material.
Shotcrete is reinforced by steel rods, steel mesh, or fibers. Due to the force with which the concrete leaves the nozzle, the material gets placed and compacted simultaneously. Some properties of hardened shotcrete are high strength, low permeability, and high durability. Because of the manner in which shotcrete is applied (high velocity), it bonds better to most substrates regardless of area or shape.
Shotcrete can be sprayed onto straight, curved, and irregular surfaces and can be applied on vertical and overhead areas too. Some structures where shotcrete is typically applied to for repair and restoration are bridges, parking garages, dams, sewers, and more. In new construction, shotcrete can be used for swimming pools, foundations, and domes
Micro Piles Gain Popularity
We often specify helical piers for foundation underpinning projects to correct building settlement conditions (see our previous post, “Screw It” http://blog.etc-web.com/?p=83 ), but occasionally we need to use micro piles instead.
As the name suggests, micro piles are small diameter piles (generally 3” to 10” in diameter) that are installed by a drilling process. These piles consist of a steel casing and/or threaded bar that is made of high strength steel. We specify this process when there is shallow bedrock, boulders, or layers of soil that are very hard.
In the past, micro piling was not a highly used process because of cost considerations and a slow installment time. But lately, it has been gaining popularity. The main reason for this are requirement to comply with low noise and vibration regulations that are generally found in urban or highly populated areas. Micro piling is also a useful technique for underpinning at sites with difficult or restricted access, including low headroom interiors and facilities that require minimal disruption to normal operations
Transformation of Welding
The basic practice of forge welding goes back thousands of years. Scholars have come to a general consensus that welding has been practiced for more than 5,500 years (since around 3,500 BCE). But it wasn’t until the 1800’s that advancements in welding technology really started taking off and resembling the processes that we use today.
In 1810, a significant change occurred when Sir Humphrey Davy demonstrated his discovery of a carbon arc by using an early version of a battery. We now know this by the term “electric lights”. This spawned many discoveries in the next 90 years. In 1836, the discovery of acetylene was made. This was needed for the production of oxyacetylene, a gas known for its high temperature flame, which is still used today to cut metals. From the years 1885 to 1910, four major patents were issued for new welding practices, including what is now known as shielded metal arc welding (SMAW) in 1910. SMAW was later automated, which led to submerged arc welding (SAW).
Nowadays, so much we see and use on a daily basis is automated, and welding is no exception. Digital circuitry has made it possible to build welding and cutting systems with computer programming and control. This has vastly improved quality control and reduced costs. The most recent major advancement in the field is the ability to take advantage of lasers and electron beams for cutting and welding.
Infrared Asphalt Repairs
Conventional pavement repair entails removal of distressed asphalt, replacing it with new-hot-mix asphalt, and rolling it to achieve compaction and a uniform surface. A major problem with that method is the creation of “cold” joints. The new asphalt will not meld with the in-place material and the joints must be periodically sealed to keep water out.
Infrared repair utilizes equipment that heats the in-place asphalt adjacent to the repair area to a plastic (workable) state and new hot-mix asphalt is placed. The new asphalt would be maintained at a similar temperature and consistency, so the materials readily blend. The asphalt can be raked to enhance consolidation and then compacted.
Done properly, the result is a seamless patch, but there are limitations. For older pavements (15 years old or older), the asphalt binders are probably too depleted or degraded to undergo infrared patching. In some instances, binder constituents can be replenished, but that’s not practicable if the asphalt is too brittle. Also, it may not be financially beneficial to spend a lot of money patching pavement that’s near the end of its useful life.
Infrared patching is not suitable for full-depth distress. Only the top two, to two and one-half inches of asphalt can be sufficiently heated to permit consolidation. Trying to raise the temperature of deeper material would likely overheat the surface asphalt and degrade the binder. Accordingly, full-depth distress must be full-depth patched. The topmost layer of a full-depth patch could be blended in with the infrared process.
Infrared methods have been employed as rehabilitation, in lieu of overlayment; however, it’s unlikely they achieve the same results in every circumstance. As noted above, the in-place asphalt must be in relatively good condition to withstand heating and binder replenishment won’t produce “new” asphalt.
Fear and Loathing in the Community Association
There is a phrase in the lives of community associations guaranteed to make the blood run cold – Special Assessment.
Property managers and boards of directors fear it, and homeowners are usually angered by it. The most common initial reaction from those affected is to find someone to blame. It has to be the fault of management, who ignored maintenance, the board of directors who didn’t budget enough to cover routine repairs and replacements, or the consultant who recommended a needlessly expensive remediation program.
It’s not always that simple and even if it is, so what? The fact remains homeowners will have to pony up or get used to living with the leaks, rotted wood, potholed pavement or whatever conditions are involved. The second option is short-sighted and will only add to the problem, so the only real option is to develop a workable strategy and sell it to the owners.
The first step is to identify and quantify the problems and define appropriate remedies. These should be done by someone who wouldn’t financially benefit from the outcome. Qualified, trustworthy contractors could do a competent job, but could be viewed as having a vested interest and their findings could be dismissed by some for that reason. Independent consultants aren’t automatically more believable, but there’s certainly less potential for a conflict of interest.
The next (and arguably most critical) issue is effective communication. Once it’s been established that a major project is necessary, the ownership should be informed and a special meeting should be convened to present it to them. The individual(s) who investigated the problems and defined the repairs should present their findings and provide exhibits (photographs, drawings, etc.). There will be questions (often pointed) and accusations should be expected. Patience, tolerance, and understanding on the part of the targets are critical.
When possible, projects should be structured to minimize financial hardship. In some cases, projects could be phased over a number of years, allowing for assessments to be paid in installments over that period. If a project doesn’t lend itself to a phased approach, it could be advantageous to obtain a loan, which would also permit payment in installments.
Reserve studies by competent professionals will help prevent the need for special assessments, but if they aren’t done early and often, or if funding recommendations are ignored, the potential could be high. Even with conscientious inspections major problems (such as latent defects) can develop without visible symptoms many years after construction.
Cracks Happen
Cast-in-place concrete will, more often than not, crack. In a nod to that characteristic, weakened planes (control joints) are formed or cut into conventionally-reinforced concrete slabs and sidewalks to influence where cracks occur. Cracking outside of control joints can indicate shortcomings in concrete placement, finishing, and/or curing, as well as influences from without. Cracks can manifest in a number of forms, most of which are of no structural concern.
Shrinkage cracks are most common and those for which control joints are used. Excessive shrinkage cracks can be caused by high water content in the concrete mix or poor control joint layout.
Plastic-shrinkage cracks are usually shallow and occur when surface water evaporates from the surface of plastic (soft) concrete faster than bleed water from below can replace it. Accelerated evaporation can occur under conditions of low relative humidity, high heat, when wind speeds exceed 5 MPH, or a combination thereof. Plastic shrinkage cracking can be controlled by various methods, including the use of wind breaks, shading provisions, water misting, etc.
Crazing or map-cracking is characterized by interconnected shallow cracks and can be caused by the same conditions that cause simple plastic shrinkage cracks. They can also be caused by poor finishing, particularly on steel-trowel finished concrete. Over-finishing can depress large aggregate and draw excessive paste and fines to the surface. High water content and rapid curing can also produce crazing.
Durability (D)-cracking is caused by the use of porous large aggregates (usually sedimentary materials such as limestone, sandstone, dolomite, shale, etc.) in regions that experience freezing temperatures. It occurs when absorbed water freezes and the resulting expansion (ice occupies about 9% more space than liquid water) breaks the aggregate. The greatest harm is caused by freeze-thaw cycling. The mid-Atlantic region experiences temperatures near the freezing point of fresh water more frequently than most other parts of the country and therefore experiences more freeze-thaw cycles. Deicing agents (such as road salt) creates brines, which have lower freezing points and thereby further increase freeze-thaw cycles.
D-cracking usually occurs near joints and can be partial or full-depth. It will often cause severe spalling and it is considered a terminal, incurable condition.
Displaced or offset cracks are characterized by a height differential on either side of a crack. When they occur at slabs-on-grade, the cause is usually a poorly prepared or unsuitable sub-grade or displacement by tree roots. Significant displacement (one-half-inch, or greater) can present tripping hazards.
Offset cracks in elevated (bridging or cantilevered) slabs could indicate a structural instability. Embedded steel reinforcement would normally prevent displacement and its failure to do so could have serious consequences.
Worth A Look!
The Washington Metropolitan Chapter Community Associations Institute’s monthly magazine is packed with articles and columns designed to help readers preserve, protect, and enhance their communities.
ETC is pleased to have two articles featured in the October Issue of Quorum. Check them out!
Tips For Dealing with Old Man Winter: Download PDF
Beauty May Be Only Skin Deep: Download PDF
Attack Of The Red Slime
There are forms of bacteria (Thiobacillus and Leptospirillum ferrooxidans)that feed on dissolved iron in groundwater. They’re not believed to be harmful to humans and are often found in well water. In sufficient concentrations, iron bacteria can impart unpleasant tastes and aromas in drinking water. They can stain sinks, bathtubs, and toilets, as well as clothes laundered in infested water.
Iron bacteria metabolizes iron into ferric oxide in the form of a gelatinous slime. That can be problematic for things like sump pumps, if the sludge is allowed to accumulate enough to clog lines or foul pumps. Premature pump failure in contaminated sumps is not uncommon. Unfortunately, iron bacteria are extremely difficult to eliminate and systems affected by them need extra maintenance/cleaning.
Depending upon the degree of contamination, sump-pump systems can require cleaning three to four times per year, or more. While elimination may not be possible, the bacteria can be somewhat controlled by the use of chemical disinfectants (such as chlorine), or exposure to high-intensity ultraviolet light. Contaminated water can also be treated with ozone, which converts the soluble iron to an insoluble form that can be filtered out, thereby reducing the nutrients needed for bacteria to thrive.
It should be noted that chemical treatments can adversely affect pumps and other devices and could create hazardous conditions. Such measures should only be undertaken by qualified service providers.
One way to minimize pump replacement in infested installations is to install those rated for the movement of soft solids. Automatic water treatment systems require considerable space and aren’t practical for every installation. In those instances, upgraded pumps are especially indicated
Buying A Condo Part 3- New Vs Old
There’s something inherently appealing about buying something brand new, but newer isn’t always better, especially in construction. A dishearteningly large portion of our work involves problems in new buildings, ranging from shoddy workmanship to new technologies that don’t live up to expectations.
One advantage to buying a unit in an older building is history. Inherent or latent defects can take time to manifest and new structures are not time-tested. There are steps that can be taken to help determine the condition of a new building, the first of which is a professional transition or warranty study.
Most states (and The District of Columbia) have in effect statutes regulating the formation and governance of community associations (condominium acts) and they typically include provisions for the correction of construction defects by the developer. That amounts to a statutory warranty, which has nothing to do with other warranties that might be offered to buyers by the developer.
Each state sets the criteria as to what constitutes a warrantable defect but they generally include any condition that reduces stability or safety below acceptable levels, restricts the intended use of a building element and/or does not comply with standards acceptable within the involved industry. Warranty periods vary by jurisdiction, usually ranging between two to three years. The acts also define periods during which lawsuits could be filed (statutes of limitations) and some limit the time an association has to notify the developer of any defects, often within the warranty period.
Before a warranty claim can be made, defects have to be identified and to the extent possible, quantified. That’s the primary purpose of a transition/warranty study. A secondary purpose can be determination of replacement reserve requirements.
Depending upon the age of the property, such a study could have been performed; however, it may not be made available to potential buyers. If the Association is embroiled in a legal action with the developer, reports might not (for strategic reasons) be made public during certain aspects of the process.
If you wish to buy into a new community and no such study has been undertaken, it would be in your best interest to propose, promote, or support one. In many cases, the burden of correcting constructions defects falls on the association if they weren’t identified within the time frames imposed by statute. Consumer protection laws in some states provide protection apart from and in addition to condominium acts, but even then, early is better.
The intent of this series is not to dissuade you from buying a condominium. All systems age and must undergo periodic repair, rehabilitation, or replacement. As long as the association has properly planned for those, the related issues amount more to inconvenience than hardship. If plans are lacking, you could be faced with having to pay for things that weren’t your fault, in the form of a special assessment or elevated assessments to pay off a loan.