Temporary Bracing

The orange steel tube is connected at both the slab and the masonry wall. This temporary bracing provides support for the wall until completion as well as ensuring the the wall remains plumb. When the wall is at a hight okay for the bracing to be put up, typically specified on the specs, bracing will be inserted into the mortar and also on the slab. The bracing on the mortar fits around a block, as noted in the picture below.

From there, the rod is attached to the wall bracing with a bolt and pin. The bracing has different holes where the bolt can go in depending on the height of the wall. This gives flexibility if you have to bolt the rod on the slab closer or further away from the wall because of conduit or other material coming out from the slab. Next the rod is attached to the slab in a similar fashion to the wall.

Although this picture doesn't show it, normally the rod allows you adjust its length so that you can get the wall plum. This allows one to fine-tune the rods length so that the wall is as close to plum as possible. It is so important that the adjustments are made because you are dealing with small units of measurement to correct a walls level. Again, the rod is attached to the ground with a bolt and pin. The bracing is held firm in place by a bolt that was shot into the concrete and then screwed tight to ensure it won't move.

Ladder Mesh Reinforcement

When laying brick and block, you need to have lateral reinforcement within your courses above and beyond your vertical reinforcement such as rebar. The above photo is an example of what a ladder reinforcement looks like to tie both block and brick together. The main ladder, the widest part shown on the right, is used for the block course. Typically, these are set every three courses and keeps the block from moving laterally and provides extra reinforcement when the block moves due to weather or other conditions.

The left "ladder" is used to tie together the brick course with the block. Here is a photo of block that has already been laid, and waiting for the exterior brick. It shows how the only thing extruding is the brick ties.

The brick is not laid directly next to the block. Usually, there is an air gap in-between the block and the brick for air to travel up and down in order to help dry up any moisture that is trapped between the brick and block. The picture below helps to illustrate this point further-

Also, flashing put in between the air cavity between the block and any sort of exterior facade to further help mitigate any moisture from traveling up the cavity, known as capillary action.

Below is a photo of some interior or exterior ladder mesh reinforcement for only block. One can tell this because it is only the one ladder system with no extrusions coming from the ladder.

The second to last photo was taken from - http://www.designerpages.com/products/119345-270-Ladder-Eye-Wire

Rollers

Rollers, or sometimes called compactors, are used for compacting soil, gravel, asphalt, etc... for constructing roadways or large foundation areas where concrete will be poured. The main use for these rollers are to smooth out roadways prior to laying asphalt. It is similar to a fine grade for finishing a grade around a building.

How does a roller work? It uses its weight and vibrating action from inside the roller to compact and flatten the area it covers. One thing I didn't realize is that in some rollers, you can fill the inside of the drum(front smooth roller) with water to achieve the particular weight that the roller needs for the job. For different applications, a roller needs to have certain weight standards in order to smooth different surfaces. If the roller is too light, then the end result will not be met and the area being rolled will not be compacted enough. Thus, your final product will be unsatisfactory.

Below is a video that I took from the Prices Fork Elementary school compacting a mid-size stone temporary road for equipment to get in and out. Since winter is already here, stone roads are needed for equipment to drive on. If these temporary roads aren't in place, equipment may sink into the wet soil and create a mess around the job site - a nightmare for any contractor.

The top image was taken from - http://www.davidtate.com/compaction.htm

Residential Piers

Above is a photo of a form for a concrete pier for a back deck of a home. The area has been dug dug out using a backhoe in order to have room to put the formwork and pour the pier. To start the formwork, 2x4's are cut to size to surround the perimeter of the pier. When the 2x4's are set in place, they are then set by a piece of rebar driven into the ground through a hole cut in the wood.

The formwork used comes in two parts. Each individual part of the form is in an L shape. Then, each L piece is connected using metal hooks that secure one piece to another. Once the forms have been completed, it is time to pour the concrete.

It is hard to tell from this photo, but there is an orange string line that runs across the pier. This string line designates the height that the concrete needs to be poured to.

Now that the concrete is poured and the anchor bolt is put into place, the forms can be removed. If you notice, there are pieces of 2x4 that cover the interior perimeter of the form. It is easy to knock the boards loose after the forms have been removed as opposed to just having the concrete poured into the form. It would be very difficult to pull apart the forms if they have been bonded with the concrete. Once the lumber has been knocked off, your pier is complete!

Concrete Forms

These men are taking down forming for a site-cast concrete wall. What you see happening is the man in the neon green safety vest hammering out pins within the metal clamps. These pins and clamps keep the wood form from coming apart. In between the horizontal 2x4 members, is a rebar tie that helps to strengthen the concrete after poured. The ties put somewhat of a camber in the wall so that when the rest of the load is built on top of the CC wall, it will settle level.

Also, the pieces of lumber that are coming off the wall at a 45 degree angle are support members to keep the wall plumb. Plumb is level but vertically. They also are used to support the wall when the concrete is poured in the form. If the forms weren't properly supported, then the forms could potentially break and concrete would go everywhere and cleanup would be a mess.

Waterproofing

This photo was taken from my commercial site during the beginning phase of the school. The black material that has been sprayed on the CMU is waterproofing. Waterproofing can either be sprayed or rolled on; it just depends on the limitations around the site.

This waterproofing application actually is not a good job. You can see towards the upper right hand corner of the picture that there are voids within the WP coat. This can cause water to get into the concrete and if exposure is prolonged, then the integrity of the concrete can be jeopardized. Also, the FD wall is not necessarily smooth. The WP coat will again have a hard time of sealing the area due to the inconsistency of where it was applied.

-- So make sure that your surface area is 1)clean 2)smooth 3) ready for the WP coat to be applied. This will make sure that your WP will hold up to its intended use.

New Way to Fix Concrete Cracks?

I ran across this article today...http://www.msnbc.msn.com/id/40201539/ns/technology_and_science-green_innovation/ It states that a certain bacteria can "fix" concrete cracks by emitting a glue like substance. Apparently, the bacteria has been trained to "swim" down concrete cracks in buildings. Once the bacteria has reached the bottom of the crack, it emits calcium carbonate and some sort of bacterial glue. The bacteria is found in soil particles and has been nicknamed "bacteriafacillia."

The researchers have found that this new method of healing concrete cracks is really useful in earthquake prone zones where there is no other alternative to fix buildings with too many cracks in the concrete.

The bacteria will only emit the glue like substance when it comes in contact with concrete. When the bacteria has reached the end of the crack, it releases three types of substances.

"This clumping activates the concrete repair process and the cells differentiate into three types: cells which produce calcium carbonate crystals, cells which become filamentous —acting as reinforcing fibers — and thirdly cells that produce a glue that acts as a binding agent and fills the gap."

What are your thoughts on the this chemical bacteria? If it does seem to work, this agent could help all types of building structures. Prolonging the life of concrete will help many buildings last long and therefor avoid being torn down. It would also alleviate costly demolition expenses. It seems like a win/win situation - - if it works!