Gordon Baker GRI, CDPE

The central Phoenix location makes the Science Center accessible for those living in Gilbert, Chandler and Mesa as well as those coming from Glendale, Avondale or Buckeye, and it is well worth the trip. Phoenix area residents are fortunate to have a facility such as the Arizona Science Center. Even better is the proximity to the light rail transit station. My family boarded the light rail in Mesa and rode into Phoenix and got off 1 block from the center. An all day light rail adult ticket was $3.50, and for children $1.75. My only regret was that we arrived so late in the afternoon that we could not take advantage of all the attractions. Fry’s was sponsoring the entire weekend so admission was free. Thank you, Fry’s.

Over 300 Hands On Exhibits Keep You Busy

One room was dedicated to making physics simple. At least that’s how I would explain it. One of the popular exhibits was a live tug of war exhibit that showed interactively how levers work. The bed of nails is always scary until you actually try it, and you had to wait in line. Another hands on exhibits demonstrated how pulleys work as kids elevated themselves in a chair by pulling on a rope that was threaded through one or more pulleys. Or you might experience rotational momentum and inertia as you were spun around so fast that you could hardly stand up. And that’s just one room. Both parents and children were equally enjoying the exhibits.

A Humble Beginning

The Science Center opened in 1984 in a small 10,000 sq.ft. storefront exhibition. In 1997, the Center opened with 120,000 sq.ft after significant fund raising and contributions. After another fund raising campaign and renovation that lasted into 2008, the Arizona Science Center now features a Planetarium, a 5 story IMAX Theatre, and more than 300 hands on exhibits. The Dorrance Planetarium is the first science center in the world to showcase a state-of-the-art NanoSeam dome.

More things to see, not enought time

We did have enough time to visit the Forces of Nature exhibit where we watched a video depicting extreme weather conditions at the same time being rained upon, blown upon and exposed to heat lamps in order to make the experience more realistic. The whole time were were standing on a movable platform so the earthquake effects were more believable.

My Digital World was the last one we visited that explained about digital technology and how information is shared. Of course, there is an explanation of how the internet works. For a more complete description of the activities, click on Science Center activities. Here is the link for Pricing and Hours. Another 2 - 3 hours would have made our trip complete.

The Arizona Science Center is impressive and deserving of at least one visit to check it out. You may even decide to become a member so you an return many times per year as the exhibits change and new ones are added.

Gordon Baker, a east valley Realtor also specializes in Phoenix waterfront homes and lake communities throughout the Phoenix valley.

Expansive soil in Phoenix and the East Valley

Post tension slabs are used to create a slab that is stronger than the typical slab and foundation that is poured in stages. Post tension slabs are used in many parts of the country and Arizona where the soil has high shrink / swell potential, commonly know as expansive soil. Parts of the Phoenix area have soil that is expansive and exhibits a high shrink / swell potential. The USDA has published a shrink / swell potential map for Phoenix which identifies the cities or towns most affected by this condition. Cave Creek, Gilbert, Chandler, and north Phoenix, and parts of north Scottsdale are such areas.

Installing Post Tensioned Slabs

Concrete performs extremely well under compression (pushed together), but poorly in tension (pulled apart). The cables or tendons are stretched with hydraulic jacks up to 25,000 psi and clamped at the ends. The result is the tendons constantly keep the concrete in compression forming a stronger more reliable foundation and slab.

The plastic sheathed cables are positioned in the slab at the correct height and distance using “chairs” or little cone shaped supports. The plastic coating allows the cables to move within the concrete after it is poured and stretched. This is why you may also hear the term unbonded, since the cables can move independently of the slab. Once the concrete is poured and has reached approximately 75% of the desired strength, the cables are stretched using a hydraulic jack. Applying the pressure to the concrete after it is poured and cured is the “post tension” part of the process and name. The cables are then anchored at the ends and allowed to cure.

Identifying Post Tension Slabs In A House?

Since the cables or tendons in the slab have been stretched to high tensile strengths, it is extremely important that you do not drill, cut, chisel or do anything to expose the tendons. An easy way to verify if the slab is post tension is to go to the edge of the garage by the garage door and check for stamped warning in the concrete similar to the one on the right.

What About Houses Without A Post Tension Slab?

The majority of the homes in Phoenix do not have post tension slabs. Home builders may choose not to use post tension slabs if the house is not in a high risk area. As you'll notice on the map, many areas and cities are considered low risk. The best approach is to consult the shrink / swell map of the Phoenix area to identify the areas where it would be a concern. If the house uses a slab on grade type of foundation, look for severe settling cracks, especially if they are recent. Settling cracks that have not moved for a long time pose less of a concern. A qualified inspector can also be a good source of information.

A simple yet critical practive that you can control is to keep water away from the house. Many home builders suggest keeping sprinklers and landscaping at least 12 – 24 inches away from the side of the house.

Being aware of the expansive soil condition is the first step. Looking for excessive settling cracks and continued settling is important. Using a qualified inspector is key and ultimately keeping water a safe distance from the perimeter of the home will help avoid further risk.

For further questions or assistance in searching for homes, feel free to call me at 480-326-8571. For homes with in law suites, guest quarters or casitas, go to East Valley Guest Quarter Homes.