Concrete is not a ductile material-it doesn’t stretch or bend without breaking. That’s both its greatest strength and greatest weakness. Its hardness and high compressive strength is why we use so much of it in construction. But concrete does move-it shrinks, it expands, and different parts of a building move in different ways. This is where joints come into play.
Although many building elements are designed and built with joints, including walls and foundations, we’ll limit this discussion to joints in concrete slabs. Here’s an overview of the types of joints, their function, and tips for locating and installing joints.
Concrete Joint Information
Different joints in concrete slabs all have the same bottom-line purpose of preventing cracks
As concrete moves, if it is tied to another structure or even to itself, we get what’s called restraint, which causes tensile forces and invariably leads to cracking. Restraint simply means that the concrete element (whether it’s a slab or a wall or a foundation) is not being allowed to freely shrink as it dries or to expand and contract with temperature changes or to settle a bit into the subgrade. Joints allow one concrete element to move independently of other parts of the building or structure. Joints also let concrete shrink as it dries-preventing what’s called internal restraint. Internal restraint is created when one part of a slab shrinks more than another, or shrinks in a different direction. Think how bad you feel when part of you wants to do one thing and another part wants to do something else! Concrete feels the same way.
If you have a question for Calvac Paving, please contact us at
2645 Pacer Ln
San Jose, CA 95111
Calvac Paving was proud to be able to serve the city of Los Altos, California by replacing a common private road within the community. The roadway needed repair for durability, safety and aesthetic reasons, giving Calvac Paving the opportunity to once again demonstrate the quality and attention to detail of our work.
This project required some delicate handling because, as a private road in a residential area, Calvac Paving had to be mindful of residents’ access needs as well as the possibility of fires or other emergencies. It also necessitated using a special process that allowed for minimum road closure time and maximum performance. We created a short video to show the highlights of the paving process, from top to bottom.
The process Calvac Paving decided to use was a “petromat” overlay on top of the existing roadway. To do this, the failed areas were prepatched using full depth hot mix asphalt. Once this was done, the existing utility boxes in the roadway were raised up, so as to secure them against further failures in the subgrade or roadway itself. An asphalt binder and paving fabric were installed next, allowing the existing road surface to bond properly to the hotmix upon placement. A 2” lift of hotmix was placed using a self-propelled paver, and then the lift was compacted to produce a smooth, level road surface.
The finished product is much nicer-looking, offers more flexibility and durability, and didn’t require as much disruption of local traffic patterns as more traditional repair and rehabilitation projects. Calvac Paving specializes in these kinds of jobs, where tight traffic constraints and the need for access make conventional processes difficult or impossible. In this particular case, we left the property owners with a smoother, more aesthetically pleasing, better-driving roadway.
Calvac Paving has been serving the Bay Area since 1974, providing the highest-quality paving, concrete and earthwork solutions for residential, commercial, transportation and public applications. From annual budgeted concrete repairs, asphalt paving and seal coat to a complete new roadway build and striping services, Calvac Paving has the equipment, knowledge and experience to deliver excellent quality at competitive prices. We approach every job with a can-do attitude and consider carefully how to proceed to obtain the best balance of cost effectiveness, performance and safety.
Because our President, Jim Adam, carries CASp certification, Calvac Paving is also an ADA-certified company. This means we are continuously keeping abreast of new developments and adaptations to ADA regulatory requirements and standards. Carrying this prestigious and important certification allows us to ensure every project we undertake is in full compliance with ADA Standards as well as the California Building Code, which in some cases are even more stringent.
In addition to our certifications and awards, Calvac Paving offers a three-year warranty to qualifying customers, three times the industry standard. We stand behind every job we do with strict quality and performance standards, because we want our clients to have peace of mind that the work they get from Calvac Paving will be the best anyone, anywhere can deliver. We hold our work to the highest possible standards for materials, workmanship and durability, Calvac Paving can take pride in giving our clients/Stakeholders a finished product they can trust.
Calvac Paving is proud to have served the Bay Area as long as we have, and we will continue to do so in 2016 and beyond. Whether we’re fixing a private roadway in Los Altos or working on a major airport runway renovation, striping a parking lot or building an access ramp to the exacting tolerances of ADAS and CBC requirements, we are passionate about our work and proud of the final result. To learn more about how Calvac Paving can help you with your next construction project, we invite you to call our offices at the following numbers:
(408) 225 – 7700
(650) 694 – 7944
(831) 375 – 7944
You can also contact us by clicking here if you’d prefer to email. For top quality, on-schedule and on-budget, don’t gamble with the results. Call Calvac Paving and get the best right from the start.
One of the processes that paving contractors can perform in these conditions of rain and clear skies is crackfilling. It takes just a day of good weather to allow us to come in and prepare the cracks with the installation of the crackfiller the following day if necessary. Here is some information concerning this service.
Linear cracking in your asphalt surface. Aged and oxidized asphalt that has intermittent cracking. These cracks are typically wide spread throughout the property and not concentrated in one area nor interlocking.
If there are alligatored areas (interconnecting cracks) then these areas should be repaired rather than crackfilled. These problems are exacerbated by the intrusion of water which will penetrate to the subgrade and accelerate cracking and base failure caused by shrink/swell of the subgrade.
Causes of this linear cracking could be a less than satisfactory base course on top of a moisture sensitive subgrade causing swell and shrinkage in that subgrade. This movement reflects through the base course and the up through asphalt surface. The infiltration of moisture through this cracked and oxidized (dried out) asphalt accelerates the damage.
Additional causes would be ground slippage, expansion and contraction due to heat and cold cycles, shrink/swell of the subgrade, the advanced age and oxidization of the asphalt surface.
Cracks that are 1/4” -3/8” can be filled with a cold pour asphalt emulsion crackfiller. Cracks that are 3/8” – 3/4” will require the use of a hot rubberized crackfiller. Cracks larger than 3/4” should be corrected with hotmix asphalt, by filling the cracks with hotmix asphalt and covering with hot pour crackfiller and better yet is to follow up with a Petromat overlay of the area.
With either application the cracks will have the existing vegetation removed and then the crack will be blown out with high pressure air and high heat. If necessary we can apply a spray sterilant to the existing vegetation prior to removal.
If we apply cold pour crackfiller, then that material is poured into the crack to bridge the opening and create a flexible filler that is then struck with a specialized squeegee to force the material deeper into the crack and to localize the coverage of the material into a thin strip at each side of the crack.
If the cracks require hot rubberized crackfiller, then that material is heated to 350°+ and the material is forced into the crack and struck flush with the surface.
If your property is in need of a asphalt/concrete repair, Calvac Paving is standing by to assist!
2645 Pacer Ln
San Jose, CA 95111
At Calvac Paving, we support technologies and construction methodologies that offer a more environmentally sound and sustainable way of creating the things we as human beings have come to rely on. From asphaltic concrete recycling to innovations such as self-healing concrete, we are always on the lookout for trends and techniques that change how we operate for a greener, healthier planet. This is why we are so excited about the possibility of roads that actually recharge electric cars as they drive! These specially designed roadways will reduce pollution, increase the performance and range of electric cars to unheard-of levels, and reduce or entirely eliminate the need for charging stations.
In the UK, this seeming science fiction is becoming science fact, as the government moves to experiment with charging roads. Operating on the same principle as a wireless phone charger, the roads will charge cars through magnetic induction resonance. Cables implanted in the material of the roadway generate a specialized electromagnetic field that the car can convert into usable energy. The roads will also include communications equipment attuned to the unique energy signature of an electric car, alerting the road that an electric vehicle is present and to initiate the power generation process. This will allow properly equipped electric vehicles to recharge on the go, without needing to stop for extended periods to recharge, one of the biggest stumbling blocks cited in the adoption of electric vehicles thus far.
The roads the UK are experimenting with will be restricted for the time being, ensuring that regular vehicles do not impede the testing process. The government is committing 500 million pounds, or roughly $779 million, to these experimental roads over a five-year span. This technology is already in use in South Korea, powering rail systems with ranges of up to 15 miles, and will be combined with an added initiative to provide charging stations every 20 miles in the UK. The combination of options for drivers will help eliminate so-called “range anxiety,” which one advocate described as a combination of running low on gas and having one’s cell phone be low on battery simultaneously.
Magnetic induction resonance works in much the same way as a powerful operatic voice can shatter crystal. When the voice and the crystal reach a similar resonance, the molecules in the crystal begin to vibrate rapidly and cause it finally to break. Instead of shattering or rupturing the battery, however, the cables the charging roads utilize will create a harmonic resonance within the battery that allows it to transform the signal from the roadway into usable power.
Because many roadways contain metal in addition to the native subgrade, road base and asphalt in the form of rebar, wire-mesh matting and metallic joints between road sections, the cables can use this metal as a part of the transmission system for the power. The metal components of the electric car can be employed as a receiver, directing the transmitted energy to the battery without the driver needing to stop, handle any charging devices or worry about whether or not the car will make it to the next charging station.
Major car production companies such as Audi are leading the research into this technology, which they believe will relegate internal-combustion vehicles to the status of horse and buggy. By working together to create a standardized plug-in system for use in garages, parking structures and ultimately at-home use, these car manufacturers believe they can make charging stations easier to find and thus make electric cars more attractive. The idea of “switching stations,” where a person can simply replace a drained battery with a fresh one and continue on, and the increased range of electric cars to around 250-300 miles per full charge depending on the type of car and battery size, will help expedite this process.
While paved roads are still very much a part of the future landscape, what drives over those roads and what lies beneath them may soon play a more crucial role than ever in our environmental integrity and ability to move people and cargo. Calvac Paving will be watching the trials in the UK with a great deal of interest, because we want to see if this technology truly is feasible and what the implications will be for the paving industry. If everything pans out as the equations and scientists claim, this could be a major breakthrough and a huge tectonic shift in how things are designed in both construction and automotive industries, as well as manufacturing and transportation as a whole. We think that’s a pretty big win, and look forward to this technology here at home!
Maintenance Mondays: This project was for a Medical Building. This required the crew from Calvac Paving to work on a Sunday to minimize disruption. The bulk of the drive lanes were damaged to the extent that we had to remove and replace approximately 45% of the drive lanes. The crew completed approximately 260 tons of removal and replaced with 260 tons of hotmix asphalt. All of the removed asphalt was hauled to a recycle plant. Our crews were completed and out of our yard and on their way home by 6:30pm.
Calvac Paving – Top Quality. On Schedule. On Budget.
Calvac Paving, a San Jose based Asphalt and Concrete maintenance and construction Contractor is looking for Equipment Operators, Laborers and Skilled Workers. We are looking for full time workers and experience in Asphalt and Concrete construction is a plus.
Applications must be completed at 2645 Pacer Lane, San Jose, CA 95111
About Calvac Paving
Over the past 40-plus years, Calvac Paving has become one of the most experienced and reliable Asphalt and Concrete contractors in Central California. Our focus on individual project attention and meeting our STAKEHOLDER’S expectations has helped us to add scores of Property Managers/Owners, HOAs, Corporate buildings and campuses, Retail as well as Multifamily properties to our list of appreciative clients/stakeholders.
With the wetter, cooler conditions of fall upon us and winter in full swing, it’s a good time to check your parking lot and other asphalt applications for signs of poor drainage and damage. It’s much easier and less expensive to catch a problem early and correct it than it is to wait until that small cracked area spreads to half the lot. With this in mind, here are four signs you should look for to check if your parking lot drainage is working as it should.
Rocks or sand in unusual places
If, after a heavy rain, you notice rocks or sand in low-lying areas, this may be an early warning sign that something’s wrong with your drainage. The water from the rain may actually be eating away at the asphalt and flushing away the solid particles of sand and rock aggregate that make up asphalt. To make sure it’s not runoff from the street or areas higher up, look for consistent ripples or waves in the deposits which are larger at the higher end and taper off toward the lower side of your lot. If you see this, your lot is probably okay, unless you see large areas where the sediment and rocks have gathered. This indicates possible low spots which could cause problems later.
Pools of water or flow down the middle of the lot
Most asphalt parking lots today are designed along a slight but apparent slope to facilitate runoff. Likewise, they are usually built with an engineered high point called a “crown,” which is intended to direct water away from the middle of the lot and down toward the drain points. Pooling and water flowing directly down the middle of the lot suggests the crown has been compromised or a possible issue with the subgrade, which will need to be addressed before the asphalt begins to buckle.
If you start to see cracks developing, especially in areas where you also see heavy water flow and/or residue such as described above, this is a sign the asphalt is beginning to fail because the water is breaking down the bitumen binder. This may also be a sign of traffic outside the asphalt’s design tolerances being present, such as large amounts of heavy trucks or construction equipment. In either case, once cracking begins, water can infiltrate the asphalt surface and accelerate the rate of failure, making repairing it a priority before it gets out of control.
Are your drain inlets working as they should?
Periodically, it’s a good idea to check your streetside and in-lot drainage inlets to ensure they’re clear of obstructions and debris which may prevent them from working as expected. In many cases, asphalt failure can be traced back to a blocked drain inlet which hasn’t been corrected. Regular property walkthroughs can help you spot problems like this before they become severe enough to warrant repair or rehab of your parking lot, and keep it working the way you expect it to for years to come.
For more information about drainage or to speak with Calvac Paving about your parking lot or other asphalt and concrete construction needs, click here to contact us!
Recycling is important for our ongoing quality of life. It allows us to reclaim and reuse materials which would otherwise go to waste, clogging up landfills and contaminating our oceans. When most people think of recycling, they may think of cans, bottles, paper or even old computers. But surprisingly, the most recycled material in America is literally right under our feet: asphalt!
Unlike many recyclables, which may have limitations on specific types which can be recycled, any asphalt pavement can be 100% recycled. The American Asphalt Association recently released 2016 data which stated about 79 million tons of asphalt was reclaimed and reused in roadway mix designs and other activities, such as reprocessing into a recycled aggregate base course for use beneath the roadways themselves. In addition, nearly 1.8 million tons of waste and byproduct material from other industries were incorporated into asphaltic concrete mix designs during 2016.
We’ve previously discussed the possible use ofplastic bottles and evencigarette butts as elements of asphalt designs which are being explored. By reclaiming these materials into asphalt, it increases their recyclability as part of the mix and helps reduce their impact in landfills. The APA says recycling asphalt saves an estimated 14,664 Olympic-sized swimming pools’ worth of landfill space each year. By adding other recyclable and waste materials to asphalt, this impact will only become greater in years to come.
Recycling asphalt isn’t just good for saving landfill space. It also reduces the environmental impact of quarrying and processing the aggregates and bituminous binders used in the asphalt production process.
Asphalt can be recycled in a number of ways. One of the most popular, and the way which reclaims 100% of the asphalt involved, is to pass chunks of asphalt through a special recycling assembly which raises the temperature to 300℉. Once the asphalt has been processed using this method, it can be laid down on roadways using existing paving technologies and techniques. In this form, it is known as Recycled Asphalt Pavement, or RAP.
Another method of asphalt recycling involves crushing asphalt at a hot mix plant and using the resulting RAP as an additive for “virgin” hot mix. This type of recycling allows for over 30% of the final product to consist of recycled asphalt. By comparison, some brands of paper cups may use only 10-25% post-consumer content, highlighting the recyclable nature of asphalt.
A third way which also reclaims 100% asphalt is to crush the asphalt down into gradations suitable for road base. Rutgers University conducted astudy in which RAP was compared to conventional aggregate subbase for use in roadways. The study showed the RAP had more elasticity and stiffness (are you sure they said this, seems contradictory) than the aggregate subbase when the two materials were laid using identical placement methodology. This means RAP is actually stronger, more resilient and better for the environment than regular aggregate road base, while delivering comparable performance as a base material.
If the environmental benefits aren’t impressive enough, consider the potential savings for recycling. That’s right, recycling asphalt costs less than new paving!One estimate places potential savings at a national average of around 55%, or between 30-80%, over virgin hot mix.
It’s up to all of us to do our part to make our world a better, cleaner and healthier place, from the global level to our own homes. At Calvac Paving, we are always on the lookout for ways to perform our work more efficiently and cost-effectively while also remaining environmentally responsible. This means keeping a close watch on new technologies, methods andCalifornia State standards which would allow us to deliver comparable or superior results with less environmental impact and greater ROI for our clients. To learn more about Calvac Paving’s commitment to the environment, or to put the four decades of experience we’ve accrued to work for you, please contact us at (408) 225-7700 or www.calvacpaving.com
With winter and its accompanying rainfall on the way, the fall is a good time to take a look at your existing pavement and make sure it’s ready for the weather to come. Calvac Paving has been in the business for over 40 years, and in that time, we’ve learned a thing or two about how to solve small problems before they have a chance to become big ones. Now, we’re pleased to present this list of simple things you can watch for so your pavement lasts longer and looks and performs better in the process, even when the worst of the California winter weather strikes!
Do a routine walkthrough of your paved areas.
Parking lotsand other paved areas should be checked at least semiannually for problems. Things to look for include:
Areas of standing water. Water can break down the asphalt binder and leak down into the subgrade, eroding it over time. This is also an indication that the pavement or subgrade may already be failing, because modern grading techniques are designed to establish a grade that flushes water away from the parking area and toward designated drainage points.
Oil or other chemicals that leak directly onto the pavement. Just like water, some chemicals associated with vehicles can cause binder breakdown and lead to subsurface problems. Cleaning up oil and other chemical spills as quickly as possible can help prevent this and keep your asphalt in better condition.
Cracks, divots or uneven areas. These can be caused by weeds growing beneath the surface, freeze/thaw patterns, standing water and oil or ongoing heavy truck traffic. Small cracks and divots are often the first visible sign of possible asphalt breakdown, and it’s more cost efficient and less intrusive to fix them when they’re small by seal coating or spot patching than it is to do a complete tearout and reinstall of the paving.
Striping: Old, dull or worn striping and pavement-level signage such as fire lane indicators and other information may be harder to see and read during winter months. Especially in ADA stalls, the striping and signage should always be clearly visible to make sure people know where these areas are.
Clear debris from drainage channels and curbs.
If water has nowhere to go, it doesn’t matter how good the drainage plan for your lot is. Making sure the drainage channels, storm sewers and other inlets to the runoff system near your property are clear of leaves, branches, garbage and other obstructions will help the water flow better and make it less likely to pool up on your property.
Limit or restrict heavy-vehicle traffic as much as possible.
Large trucks such as semis, garbage trucks and other heavy vehicles can place a lot of stress on asphalt. By itself this shouldn’t be a problem, but when the base course and subgrade are compromised by water or plant intrusion, it could speed up the breakdown process for the asphalt. If at all possible, try to limit, restrict or even out the traffic pattern for such vehicles within your lot to minimize the time they spend on your pavement.
Be sure it’s sealed.
Even if your parking area is free from cracks and other problems, it is a good idea to have it seal coated every 4 to 5 years at the minimum. This is because seal coating helps rejuvenate the asphalt binder at the surface, adding an extra layer of protection against traffic, water and other spills. Even better, it will help make your parking lot and driveways look newer, especially when you redo the striping at the same time. This makes your property more attractive, safer to navigate and less likely to fail for the long haul.
Seek professional help.
If you’re not sure if the paving problems you’ve identified are “big enough,” or if you think your pavement needs a facelift or a complete overhaul, Calvac Paving can help. We’ve been serving the Bay Area for over four decades with quality construction solutions including:
Curb and gutter remediation, repair and replacement
Paving rehabilitation, tearout and reconstruction
ADA access compliance and signage
And much more!
We take great pride in delivering a great product for your project, within the schedule and budget we agree upon. For more information about how Calvac Paving can help you with your paving or asphalt project, please contact us for a no charge estimate.
2645 Pacer Ln
San Jose, CA 95111
Sealcoating is an important process in the maintenance of your all too expensive parking lots. We all know that the costs for paving repairs have increased. This makes it all the more important to protect and preserve your asphalt surface. Calvac Paving has been applying sealcoat for over 40 years, longer than most Bay Area Suppliers have been making asphalt based sealcoats. Each successive generation of sealcoats has provided greater protection from premature wear, moisture intrusion and oxidation. Even with these improvements we strongly recommend the addition of latex and sometimes sand to the existing asphalt sealcoats to extend the life expectancy of these applications. It is also vital for you to have your contractor apply two coats of sealcoat to your property. The first coat, with the added sand and latex, is the filler coat and allows placement of a second coat with added latex only or wear coat.
Preparation of the existing asphalt surface is a very important process in sealcoating your parking lot. Calvac Paving will spend the time necessary to clean and prepare your asphalt to assure a durable and attractive product. We will remove all vegetation, and apply herbicide if appropriate. We will use Power blowers, scrapers, wire brushes and brooms to thoroughly clean the existing asphalt.
This preparation may also include Mobile Sweepers, water trucks or buggies and vacuum trucks. We will burn, scrape and carefully clean the oil spots and apply an oil spot sealer with sand. We will mask utility covers and other structures to protect against coverage. We will apply hot rubberized or coldpour emulsion crackfiller as directed.
The consistency of the asphalt sealer is also very important to the durability of your sealcoat project. Calvac Paving will never exceed the manufacturer’s recommendations for dilution. This addition of water is necessary for the application and actually improves the bonding to the existing asphalt surface. We feel the addition of latex and sand to the asphalt sealer extends the life of the sealer, and we include these admixtures in well over 90% of our sealcoat projects. By extendeding the life of your sealcoat surface with added latex, you reduce the number of times you will need to seal coat and stripe your lot as well as impose upon your tenants over the life of the asphalt.
The combination of effective barricading and traffic control with superior craftsmanship and products will provide you with the best result with the least impact upon you and your tenants.